Copyright: © 1999-2002 Trimble Navigation Limited


To abort a GPS processing session

 Overview and More Information

Once a GPS baseline processing session begins, the processor performs a continuous sequence of processing passes on each of the selected baselines. The number of passes and the actions performed on each pass are influenced by the GPS processing style settings and the results of earlier passes. You can abort this process to cancel the current GPS processing session.

When GPS processing is aborted, the processor will stop processing as soon as the Cancel message is received. Note, however, that in some situations there may be a delay between the time you click Cancel and the time the baseline processor receives this message.

To abort GPS processing:

1.	Click Cancel. The GPS processor displays a verification message.

2.	Do one of the following:

  Click Yes to confirm that you want to cancel the processing session.

  Click No to continue with the processing session and abort the cancel.


To adjust the time span of an occupation

 Overview and More Information

The time span of a Static Occupation or Continuous Kinematic Occupation Segment can be adjusted to span a shorter duration of time. The time span can be adjusted by:

  editing the occupation properties.

  directly editing the occupation element.

Instructions for adjusting the time span using both methods are described below.

To adjust the time span of the occupation properties:

1.	To view the occupation’s properties, do one of the following:

  Double-click the occupation element.

  Right-click the occupation element, and then select Properties.

The Occupation/Data Segment Properties dialog appears.

2.	Edit the Start and End Time fields.

The duration of the time span can only be decreased.

3.	Click OK.

The dialog closes and the changes are reflected in the appearance of the occupation element. The element appears as a rectangle with a black border. The black border shows the original time span of the occupation element and the rectangular area filled with color, within the rectangle, shows the span of time occupied by the edited occupation element.

To adjust the time span:

1.	Move the mouse over the leading edge of the Occupation element.

The cursor becomes a horizontal-double arrow.

2.	Press and hold down the left mouse button.

3.	Watch the Time Ruler while dragging the leading edge of the occupation to the right.

As the leading edge moves, the fill color moves in unison with the mouse, but the black rectangular border remains in place.

NOTE: You can use the an empty portion of an occupation element (an area void of fill color) as an indicator that an occupation’s time span has been edited.

4.	Release the left mouse button when the leading edge of the occupation is aligned to the correct time period in the Time Ruler.

5.	Repeat the above steps to adjust the trailing edge of the occupation, but reverse the movement of the mouse.


To analyze a GPS Baseline Processing report

 Overview and more information

After GPS baseline processing, warning flags may appear in the graphics window. For GPS baselines, a flag appears in the center of baselines that did not pass one or more of the quality acceptance tests as defined in the active GPS processing style. Flagged baselines should be examined more closely to determine why they received the flag, and troubleshooting techniques may be required to improve the overall quality of the baseline solution by reprocessing using a different GPS processing style.

Progressively analyze and correct the data for each baseline separately. Correct any problems found in a particular baseline solution and reprocess the baseline before analyzing the next baseline.

Look at the GPS Baseline Processing report statistics for the baseline, and ask the following questions:

  What is the solution type?

  How does the ratio compare to the reference variance?

  What is the slope distance?

  Is there a redundant baseline measured at a different time to compare slope distances and baseline components?

If the answers are questionable, ask:

  How long was the occupation time?

  Is the RMS less than 15 mm?

  Do the tracking summaries show gaps in the processed segments?

  Do the residual plots revolve symmetrically around zero within a 15 mm range?

To analyze the results of the Ratio, Reference Variance, and RMS tests, you need to understand the criteria used to accept and reject baseline solutions.

Other GPS processing style settings can influence the results of these acceptance tests. You should develop a working knowledge of these settings to understand how solutions are accepted and rejected. For more information, see Edit Advanced Style dialog.

These troubleshooting techniques may or may not improve baseline statistics. Try them one at a time before returning to the field. These techniques are listed in order of simplicity and effectiveness. Troubleshooting may make reobserving one or more baselines in the field unnecessary.

Troubleshooting:

  Disabling a satellite

  Editing cycle slips

  Editing invalid range data

  Evaluating and raising the elevation mask

For more information about baseline processing session, see Baseline Processing Log.


To analyze satellite tracking data on SV plots

 Overview and More Information

Once satellite tracking information is plotted in the SV Plot window, the data can be visually analyzed for inconsistencies.

Multiple plots of satellite tracking information can also be plotted in the same SV Plot window to compare data. New windows can also be created to display additional sets of one or more plots.

In addition to plotting the data on the screen, the plots can be printed and the information used to generate the plot can be exported to a file in tabular format.

To plot the data:

1.	To view the Timeline, do one of the following:

  Select View / Timeline.

  Press Alt+VI.

The Timeline appears.

2.	Click a data folder.

Data folders appear in the control bar. A [image] symbol appears when data folders are closed and a [image] appears when they are opened.

Data folders display the model and serial number of the receiver used to collect the data. You can double-click on a data folder to display the receiver properties associated with the collected data.

When opened, icons appear in the control bar for all satellites tracked over the survey time span.

NOTE: Instead of opening individual folders, the Expand All command can be used to open all data folders.

3.	Double-click a Satellite icon.

The SV Plot window appears.

4.	To display satellite tracking information plots, do one of the following:

  Select one or more plots by clicking dialog bar buttons.

  Select one or more commands from the View / Data submenu.

All applicable data collected for the selected satellite over the observation time span is plotted.

5.	Visually check the plotted satellite tracking information and look for inconsistencies in the data.

Once the plot is displayed, you also can perform these actions:

To display plot measurements:

1.	Move the mouse cursor across the plot to the desired location.

2.	Read the measurement and time information in the status bar.

The value recorded at the mouse location and the time when the data was collected appears in the status bar.

To print the plot:

1.	To select the Print command, do one of the following:

  Select File / Print.

  Press Ctrl+P.

  From the toolbar, click [image].

The Print dialog appears.

2.	Select the desired options.

3.	Click OK.

The plot is printed.

To print the plot to a file:

1.	To select the Print command, do one of the following:

  Select File / Print.

  Press Ctrl+P.

  From the toolbar, click [image].

The Print dialog appears.

2.	Select the Print to File option.

3.	Click OK.

The plot is printed to a file. Many programs can import graphic data printed to a file. This is useful for including plots in reports.

To print tabular data:

1.	To select the Export command, do one of the following:

  Select File / Export.

  Press Alt+FE.

The File Export dialog appears.

2.	Select the directory and file name for storing the file.

The satellite tracking information used to generate the plot is written to a text (*.txt) file and stored in the selected folder. The data is written to the file in tabular format. When multiple plots are displayed in the same SV Plot window, one column of tabular data is included for each type of plot.


To change a static occupation type

 Overview and More Information

The Occupation Type of a Static Occupation can be changed.

To change occupation type:

1.	Double-click the occupation element. The Occupation/Data Segment Properties dialog appears.

2.	Open the Segment Type list.

3.	To select the Occupation Type, choose one of these options:

  Static Occupation

  Continuous Segment

  Roving Segment

4.	Click OK.

The changes are saved.

WARNING:  You cannot change a Continuous Segment or a Roving Segment back to a Static Occupation once the change takes effect. Use caution when making this change.


To change a continuous segment type

 Overview and More Information

The Occupation Type of a Continuous Kinematic Segment can be changed.

To change occupation type:

1.	Double-click the occupation element. The Occupation/Data Segment Properties dialog appears.

2.	Open the Segment Type list.

3.	To select an Occupation Type, choose one of these options:

  Continuous Segment

  Roving Segment

4.	Click OK.

The changes are saved.

NOTE:  You can only change a Continuous Segment to a Roving Segment. It is not possible to turn a Continuous or Roving Segment into an Occupation.


To change time options

 Overview and More Information

The units of time in the Time Ruler can be set to GPS week/seconds or Windows local time.

To change time units:

1.	To display the Time Options dialog, do one of the following:

  Double-click in the Time Ruler.

  Right-click in the Time Ruler and select Time Options.

The Time Options dialog appears.

2.	Select one of these time formats:

  Local time, which corresponds to the Windows time display format

  GPS Weeks/Seconds

3.	Click OK.

The Start and End Time fields in the Time Ruler are updated to show the change in time units. This operation also affects the units of time displayed in Timeline property dialogs, Skyplot, DOP Plot, SV Plot, and the status bar.


To correct for cycle slips in GPS observations

 Overview and More Information

Cycle slips found in the satellite tracking plots of a GPS observation can be edited to selectively remove them from future GPS baseline processing sessions. Cycle slips should only be edited in cases where the a baseline solution is flagged due to high observation residuals and large numbers of cycle slips are discovered using Timeline.

NOTE: In most cases the baseline processor handles cycle slips automatically and manual editing is not required. Cycle slips can be detected before or after processing GPS baselines by examining the GPS observations in Timeline. The problematic data has a distinctive appearance in the satellite tracking plots within GPS observations. The appearance of cycle slips and other gaps in satellite tracking information are illustrated in GPS Observations.

To edit cycle slips:

1.	Print the GPS Baseline Processing report for the flagged baseline.

Trimble recommends that you print the processing results for the flagged baseline solution before proceeding. When the baseline solution is later reprocessed, you can use the data to compare the results with the results collected for the next GPS baseline processing session.

2.	Examine the GPS observations for the visual signs of cycle slips.

3.	Drag a selection rectangle around the cycle slip.

Timeline automatically selects the tracking information for the L1 and L2 carriers. In step 6, you will have the option to delete selected L1 and L2 carrier data.

4.	To view the GPS observation properties, do one of the following:

  Double-click the selection rectangle.

  Right-click the selection rectangle and select Properties.

The GPS Observation Properties dialog appears.

5.	Edit one or both of the Start and End Time fields.

If you adjust the times to ignore the data, the cycle slip is removed from future GPS baseline processing sessions. Later when you reprocess the baselines, the processor effectively ignores the data when determining new solutions for flagged baseline.

6.	Clear the check marks from the applicable Observation Types. This determines which Observation Types will be disabled for the specified time span.

7.	Click OK to apply your changes. The dialog closes, and the color of the disabled satellite tracking data within the selection rectangle turns gray, indicating that the data will no longer be used by the processor to determine a baseline solution during future processing sessions.

8.	To reprocess baselines, select Survey / Process GPS Baselines. The GPS Processing dialog appears and baseline processing begins.

9.	Select the solution from the GPS Processing list.

10.	Click Report. The GPS Baseline Processing report appears.

11.	Compare new processing results for the baseline with the results from the earlier baseline processing session.

12.	After comparing the results from the two baseline processing sessions, do one of the following:

  If the baseline slope distance and the statistics have improved, save the baseline solution to your network.

  If no improvement is indicated, return to the GPS Observation Properties dialog, re-enable the disabled observation types, then click OK.


To correct for invalid range data in GPS observations

 Overview and More Information

Finding invalid range data in the satellite tracking plots of a GPS observation is a rare occurrence compared to finding cycle slips. In the unlikely event that this does occur, the invalid range data can be edited to selectively remove it from future GPS baseline processing sessions. Invalid range data should only be edited in cases where a baseline solution is flagged due to high observation residuals and invalid range data is discovered upon further examination in Timeline.

NOTE: Invalid range data can be detected before or after processing GPS baselines by examining the GPS observations in Timeline. The problematic data has a distinct appearance in the satellite tracking plots within GPS observations. The appearance of invalid range data, cycle slips, and other gaps in satellite tracking information are illustrated in GPS Observations.

To edit invalid range data:

1.	Print the GPS Baseline Processing report for the flagged baseline.

Trimble recommends that you print the processing results for the flagged baseline solution before proceeding. When the baseline solution is later reprocessed, you can use the data to compare the results with the results collected for the next GPS baseline processing session.

2.	Examine the GPS observations for the visual signs of invalid range data.

3.	Drag a selection rectangle around the invalid range data.

Timeline automatically selects the tracking information for the L1 and L2 carriers. In step 6, you will have the option to delete selected L1 and L2 carrier data.

4.	To view the GPS observation properties, do one of the following:

  Double-click the selection rectangle.

  Right-click the selection rectangle and select Properties.

The GPS Observation Properties dialog appears.

5.	Edit either or both of the Start and End Time fields.

By adjusting the times to ignore the invalid range data, the data is removed from future GPS baseline processing sessions. Later when you reprocess the baselines, the processor effectively ignores the data when determining new solutions for the affected baseline.

6.	Clear the check marks from the applicable Observation Types. This determines which Observation Types will be disabled for the specified time span.

7.	Click OK to apply your changes.

The dialog closes, and the color of the disabled satellite tracking data within the selection rectangle turns gray, indicating the data will no longer be used by the processor to determine a baseline during future processing sessions.

8.	To reprocess the solution, do one of the following:

  Select Survey / Process GPS Baselines.

  Press F9.

The GPS Processing dialog appears and baseline processing begins.

9.	Select the solution from the GPS Processing list.

10.	Click Report. The GPS Baseline Processing report appears.

11	Compare the processing results with the results from the earlier processing session.

12.	After comparing the results of the two processing sessions, do one of the following:

  If the baseline has improved, save the baseline solution to your project.

  If no improvement was indicated, return to the satellite icon and re-enable the measurements for that satellite.


To disable a satellite

 Overview and More Information

You can examine the GPS observations in Timeline to help understand baseline processing problems. Some conditions that may cause problems include:

  cycle slips, invalid phase, and numerous gaps in L1 or L2 tracking.

  poor satellite geometry, especially if one or more satellites are disabled.

NOTE: Disabling a satellite also disables all GPS observations associated with the satellite. It is possible to disable individual GPS observations and selected regions of a GPS observation. For more information, see Correcting Cycle Slips and Correcting Invalid Range Data.

To disable a satellite:

CAUTION: Before disabling a satellite, ensure that the geometry of the satellite constellation will not be adversely affected by removing that satellite.

1.	To view Timeline, do one of the following:

  Select View / Timeline.

  Press Alt+VI.

Timeline appears.

2.	Identify the data folder containing the data. Then locate the Survey element that contains the time for which you want to disable satellites. Use the Zoom to Span command to enlarge the Survey Element to fill the Time Span Viewer.

You can identify the applicable folder in two ways: the folder itself lists the receiver model number and serial number, and the Survey element includes a label with the survey session ID.

3.	To open the data folder, click [image].

The icons for each satellite contributing data to the survey appear in the control bar, and the Time Span Viewer displays the GPS observation elements for each satellite.

NOTE: If you need to show the data for all satellites in the Time Span Viewer, resize the Timeline view area.

4.	Scan the GPS observation elements for gaps.

Gaps in the L1 and L2 carriers could indicate satellite signal cycle slips, invalid range errors, and other signal loss problems. For more information about the appearance of cycle slip and other carrier loss problems, see GPS Observations.

5.	Right-click a Satellite icon.

6.	Select Enable/Disable. The GPS observation element appears gray when data is disabled.

7.	Select the baseline.

8.	To reprocess the solution, do one of the following:

  Select Survey / Process GPS Baselines.

  Press F9.

The GPS Processing dialog appears and baseline processing begins.

9.	Select the solution from the GPS Processing list.

10.	Click Report. The GPS Baseline Processing report appears.

11	Compare the processing results with the results from the earlier processing session.

12.	After comparing the results of the two processing sessions, do one of the following:

  If the baseline has improved, save the baseline solution to your project.

  If no improvement was indicated, return to the satellite icon and re-enable the measurements for that satellite.


To disable GPS observations in Timeline

 Overview and More Information

In Timeline, you can disable individual GPS observation elements, groups of GPS observations, or all GPS observations for a particular satellite. Before disabling GPS observations, ensure that removing the satellite does not adversely affect the geometry of the constellation.

NOTE: Selected regions of GPS observations and selected raw satellite tracking information can be edited to improve overall observation quality. For an example of this technique, see Correcting Invalid Range Data.

To disable individual GPS observations

1.	Click the enabled GPS observation.

2.	Right-click the GPS observation.

3.	Select Enable/Disable.

The enabled GPS observation is disabled, and its appearance changes to show its disabled state.

To disable groups of GPS observations:

1.	Drag a selection rectangle around the group of GPS observations.

2.	Right-click within the selection rectangle.

3.	Select Enable/Disable.

The enabled GPS observations are disabled, and their appearance changes to show their disabled state.

To disable all GPS observations for a particular satellite:

1.	Click the Satellite icon associated with the GPS observations.

2.	Right-click the icon.

3.	Select Enable/Disable.

The satellite and all associated GPS observations are disabled.


To edit the acceptance criteria for GPS processing

Three GPS processing quality tests (the Ratio test, the Reference Variance test, and the RMS test) serve as quality acceptance criteria for accepting and rejecting baseline solutions.

To edit the acceptance criteria:

1.	To view the GPS Processing Styles dialog, do one of the following:

  Select Survey / GPS Processing Styles.

  Press Alt+UP.

The GPS Processing Styles dialog appears.

2.	Select the active style from the list.

3.	Click Edit. The Edit Style dialog appears with the style name in the title bar.

4.	Click Advanced. The Edit Advanced Style dialog appears.

5.	Select the Quality tab. The Acceptance Criteria Group includes check boxes for enabling and disabling the three acceptance tests. In the dialog, these are referred to as the If Ratio, If Reference Variance, and If RMS fields. Four data-entry fields are included for each test. Two sets of Flag and Fail fields exist; one set is for single-frequency receivers and the other is for dual-frequency receivers.

NOTE:  There are two circumstances when the single frequency acceptance criteria are used for a baseline.  The first is when at least one of the receivers for the baseline is a single frequency receiver.  The second is when the length of the baseline is less than the Final Pass cutoff specified on the Iono tab of the Active GPS Processing style.

6.	Select or clear the If Ratio check box to enable or disable the ratio acceptance test.

7.	Type a Flag value for single- or dual-frequency receivers.

8.	Type a Fail value for single- or dual-frequency receivers.

9.	Select or clear the If Reference Variance check box to enable or disable the reference variance acceptance test.

10.	Type the Flag value for single- or dual-frequency receivers.

11.	Type a Fail value for single- or dual-frequency receivers.

12.	Select or clear the If RMS check box to enable or disable the RMS acceptance test.

13.	Type a Flag value for single- or dual-frequency receivers.

14.	Type a Fail value for single- or dual-frequency receivers.

15.	Edit the Edit Multiplier and click OK.

The changes are saved.

NOTE: It is not necessary to modify the acceptance criteria for most survey applications. The exception, however, is for code-only final pass solutions. Code-only solutions typically are flagged based on the criteria supplied in the Trimble default processing style. If you routinely process Code-only final pass solutions, Trimble recommends that you set up a Code-only processing style with appropriate acceptance criteria.


To edit GPS processing style events options

The Events options in the GPS processing style determine how event positions are derived when continuous kinematic surveys with event markers are processed.

To edit Event options:

1.	Open the Edit Advanced Style dialog.

2.	In the Events tab, select one of the Interpolation Method options.

3.	In the remaining fields, enter the following:

  The number of points to fit

  The maximum allowed missing epochs

  The time offset (in microseconds)

4.	If no other changes are required, click OK.

The changes are saved and you are returned to the Edit Style dialog.

NOTE: For most survey applications it is not necessary to modify the advanced controls. If you do modify these controls, make sure that you understand the possible effects of these changes before saving the modifications and assigning the revised style as the active style.


To edit GPS processing style iono options

 Overview and More Information

The Ionospheric options in the GPS processing style are used to compensate for ionospheric errors when performing Ambiguity Resolution and Final processing iterations.

To edit Ionospheric options:

1.	Open the Edit Advanced Style dialog.

2.	Select the Iono tab.

3.	In the Ambiguity resolution pass group, select or clear the Apply to all baselines longer than check box to enable or disable this option. If the option is enabled, enter the appropriate distance value.

4.	In the Final pass group, sleect or clear the Apply to all baselines longer than check box for the Final Pass to enable or disable this option. If the option is enabled, enter the appropriate distance value.

5.	If no other changes are required, click OK.

The changes are saved and you are returned to the Edit Style dialog.

NOTE: For most survey applications it is not necessary to modify the advanced controls. If you do modify these controls, make sure that you understand the possible effects of these changes before saving the modifications and assigning the revised style as the active style.


To edit GPS processing style kinematic options

The Kinematic options in the GPS processing style are applied when processing Kinematic observations.

To edit Kinematic options:

1.	Open the Edit Advanced Style dialog.

2.	Select the Kinematic tab.

3.	In the appropriate fields, enter the following:

  minimum reference observation time (in seconds)

  minimum static initialization observation time (in seconds)

  minimum known point initialization (a ratio)

  minimum OTF processing time (in seconds)

4.	If no other changes are required, click OK.

The changes are saved and you are returned to the Edit Style dialog.

NOTE: For most survey applications it is not necessary to modify the advanced controls. If you do modify these controls, make sure that you understand the possible effects of these changes before saving the modifications and assigning the revised style as the active style.


To edit GPS processing style OTF search options

The OTF Search options in the GPS processing style are used to perform on-the-fly searches during GPS processing iterations.

To edit the OTF Search options:

1.	Open the Edit Advanced Style dialog.

2.	Select the OTF Search tab.

3.	In the Search method group, select the appropriate option. If you select the Forward sequential search or Backward sequential search options, the field in the Sequential control group becomes available.

4.	Enter a minimum search ratio.

5.	If no other changes are required, click OK.

The changes are saved and you are returned to the Edit Style dialog.

NOTE: For most survey applications it is not necessary to modify the advanced controls. If you do modify these controls, make sure that you understand the possible effects of these changes before saving the modifications and assigning the revised style as the active style.


To edit GPS processing style quality options

The Quality options in the GPS processing style are used to enable, disable, and define the Ratio, RMS, and Reference Variance tests used to evaluate baseline quality before a baseline is saved to the project.

Baselines that fail the acceptance test criteria are, by default, not saved to the project. A baseline that is flagged is saved to the project, but a red warning flag is displayed in the center of the baseline to indicate that this baseline should be checked to ensure it fits properly into the network. For more information about identifying why baselines are flagged, see Data Analysis.

To edit the Quality options:

1.	Open the Edit Advanced Style dialog.

2.	Select the Quality tab.

3.	In the Acceptance criteria group, select or clear the If ratio, If reference variance and If RMS check boxes to enable or disable these tests.

4.	Select the appropriate Flag and Fail fields for each test, and enter the required values.

NOTE: Trimble recommends that you do not change the default settings which are suitable for most survey applications.

5.	In the Edit multiplier field, enter a value.

6.	If no other changes are required, click OK.

The changes are saved and you are returned to the Edit Style dialog.

NOTE: For most survey applications it is not necessary to modify the advanced controls. If you do modify these controls, make sure that you understand the possible effects of these changes before saving the modifications and assigning the revised style as the active style.


To edit GPS processing style static options

The Static options in the GPS processing style are used when processing baseline data collected using Static survey methods.

To edit the Static options:

1.	Open the Edit Advanced Style dialog.

2.	Select the Static tab.

3.	In the Minimum Baseline Observation Time field, enter a value, in seconds.

This is the minimum baseline observation time elapsing before processing simultaneous measurements collected from two or more receivers. The processor requires 120 seconds of simultaneous data to process a baseline between receivers. This removes accidental overlap with multiple rovers. The default is 120 seconds.

4.	In the Maximum Baseline Length to Attempt a Fix Solution group, do the following:

  In the Using broadcast ephemeris field, enter a baseline distance (in project units). The default is 200 kilometers.

  In the Using Precise Ephemeris field, enter a baseline distance (in project units). The default is 2000 kilometers.

5.	If no other changes are required, click OK.

The changes are saved and your are returned to the Edit Style dialog.

NOTE: For most survey applications it is not necessary to modify the advanced controls. If you do modify these controls, make sure that you understand the possible effects of these changes before saving the modifications and assigning the revised style as the active style.


To edit GPS processing style tropospheric options

The Tropo options in the GPS processing style are used to apply tropospheric corrections during baseline processing.

To edit the Tropo options:

1.	Open the Edit Advanced Style dialog.

2.	Select the Tropo.

3.	In the Model list, select the appropriate tropospheric model.

4.	In the Estimated Zenith Delay Interval, enter a value, in hour units.

The minimum recommended estimation interval is one hour. The default value is two hours. A value of zero (0) results in no zenith delay estimation. This field is not available when the tropospheric model is set to None.

5.	Select the Use observed met data check box to select the type of meteorological data applied when computing GPS processing solutions. Met (Meteorological) data consists of relative humidity, barometric pressure, and temperature.

  When this check box is selected, observed meteorological data present in the data file or RINEX file is used to model the troposphere when computing the tropospheric zenith delay. By default, this check box is selected.

  Clear this check box to use standard met values in place of the recorded met data.

6.	If no other changes are required, click OK.

The changes are saved and your are returned to the Edit Style dialog.

NOTE: For most survey applications it is not necessary to modify the advanced controls. If you do modify these controls, make sure that you understand the possible effects of these changes before saving the modifications and assigning the revised style as the active style.


To edit GPS processing styles

 Overview and More Information

Two levels of dialog boxes can appear when editing GPS processing styles. General settings are displayed first and an optional set of Advanced settings can be displayed to fine tune the GPS processing style. Initially, both dialogs use the Trimble Geomatics Office software’s default style settings, suitable for most survey applications.

To edit the General style options:

1.	Do one of the following:

  Select Survey / GPS Processing Styles.

  Press Alt+UP.

The GPS Processing Styles dialog appears.

2.	Select a style from the list.

3.	Click Edit. The Edit Style dialog appears.

4.	In the Elevation Mask field, enter an elevation mask value. The specified elevation mask overrides the elevation mask used to collect the data.

5.	In the Ephemeris list, select Broadcast or Precise. If Broadcast is selected, the GPS processor uses the broadcast ephemerides collected for all satellites contributing data to the survey session. If Precise is selected, the GPS processor uses the current precise ephemeris imported into the project.

6.	In the Solution Type list, select Code, Float, or Fixed.

7.	Do one of the following:

  If the general setting changes are the only ones required, click OK to save your changes.

  Perform the next series of steps if you need to edit the Advanced options.

To edit the Advanced options:

  In the Edit Style dialog, click Advanced.

The Edit Advanced Style dialog appears. It contains the following tabs:

  Static

  Kinematic

  Global

  Quality

  Tropo

  Iono

  Event

  OTF Search

Once you have edited the appropriate options in this dialog, click OK. The changes are saved and you are returned to the Edit Style dialog.

NOTE: For most survey applications it is not necessary to modify the advanced controls. If you do modify these controls, make sure that you understand the possible effects of these changes before saving the modifications and assigning the revised style as the active style.


To edit GPS processing style global options

The Global options in the GPS processing style are considered when performing each GPS processor pass.

To edit Global options:

1.	Open the Edit Advanced Style dialog.

2.	Select the Global tab.

3.	In the Frequency type list, select L1, L2, Narrow lane, or Wide lane.

4.	In the remaining fields, enter the following:

  maximum fixable cycle slip (in seconds)

  maximum iterations (an integer value) − The GPS processor will perform no more than the maximum number of iterations while processing each baseline solution.

  maximum integer search time (an integer value, in minutes) − The GPS processor will abort further processing iterations when this time value elapses, and will use a float solution.

5.	If no other changes are required, click OK.

The changes are saved.

NOTE: For most survey applications it is not necessary to modify the advanced controls. If you do modify these controls, make sure that you understand the possible effects of these changes before saving the modifications and assigning the revised style as the active style.


To edit the ambiguity resolution pass baseline distance

This check box enables or disables ionospheric model correction during the ambiguity resolution GPS processing pass. The distance value entered in the Apply to All Baselines Longer Than field determines the minimum baseline length or threshold for applying ionospheric model corrections.

NOTE: Ionospheric modeling applies only to baselines observed with dual-frequency receivers.

To edit this value:

1.	Open the Edit Advanced Style dialog.

2.	Select the Iono tab.

3.	In the Ambiguity Resolution Pass group, select the Apply to all baselines longer than check box.

When the check box is selected, the GPS processor applies an ionospheric model to correct the ionospheric bias. The ionospheric correct method is automatically selected based on whether single or dual-frequency data exists in the project data base. One of these actions is performed when the check box is selected:

  If all project data was collected using dual-frequency receivers, the GPS processor attempts to produce an ionospheric-free observable by applying ionospheric model corrections to baselines longer than the distance specified in the Apply to All Baselines Longer Than field. The ionospheric corrections start in the code solution and the modeling action gradually improves for each successive solution.

  If at least one data file was collected using a single-frequency receiver, the GPS processor uses ionospheric data included in the broadcast ephemeris to remove 50% of the ionospheric error.

4.	In the Apply to all baselines longer than field, enter a distance value, in project units.

By default, ionospheric model corrections for the ambiguity resolution pass are enabled for baselines longer than 10 kilometers.


To filter Timeline elements

 Overview and More Information

Commands are available on the Timeline toolbar and menus for filtering the graphic elements appearing in the Time Span Viewer.

Filtering Ephemeris Icons

Select the Ephemeris command to filter the Ephemeris icons displayed in the Time Span Viewer. This command shows or hides Ephemeris icons each time it is used.

To filter Ephemeris icons, do one of the following:

  Right-click the Time Span Viewer background, and select View Filters / Ephemeris.

  From the Timeline toolbar, click [image].

Filtering Continuous Kinematic Occupation Segments

Select the Continuous command to filter the Continuous Segment elements displayed in the Timeline Time Span Viewer. This command shows or hides Continuous Segment elements each time it is used.

To filter occupation segments, do one of the following:

  Right-click the Time Span Viewer background, and select View Filters / Continuous.

  From the Timeline toolbar, click [image].

Filtering Satellites and Associated GPS Observations

The Satellites command can be used to filter the Satellites and GPS observation elements displayed in the Time Span Viewer. This command shows or hides Satellite icons and GPS observation elements each time it is used.

To filter Satellites, do one of the following:

  Right-click the Time Span Viewer background, and select View Filters / Satellites.

  From the Timeline toolbar, click [image].

Filtering Event Icons

Select the Events command to filter the Events displayed in the Time Span Viewer. This command shows or hides Event icons each time it is used. Event data must exist in the project before this button becomes active.

To filter events:

  From the Timeline toolbar, click [image].


To move columns in the GPS Processing list

 Overview and More Information

The columns in the GPS Processing list can be moved to new locations in the list. The column moves are temporary and revert back to their original locations when the next GPS processing session begins.

To move columns:

1.	Move the cursor over the header for the column.

The header contains the title of the column and is located above the first row of data.

2.	Perform one of these actions:

  To move the column to the right, drag the header right until its left side passes beyond the position where you want to insert the column, then release the mouse button.

  To move the column left, drag the column header left until its right side passes beyond the position where you want to insert the column, then release the mouse button.


To navigate through Timeline using the Time Span Viewer

Use these actions to pan the timeline through the Time Span Viewer:

  Use the scroll bars to shift the timeline left or right.

  Adjust the Start or End Time fields to pan to a specific time period.

  Use the Zoom Extents command to view the entire timeline.

  Use the Zoom to Span command to zoom and the selected element to the width of the Time Span Viewer.

  Use the Next command to pan to the next occupation end point.

  Use the Previous command to pan to the previous occupation start point.

Use these actions to view data vertically:

  Drag the top border of the Timeline view area upwards or downwards to show more or less information.

  Open and Close the data folders in the control bar to view more information.

  Use the vertical scrollbars to move up and down through the data.

Consider these guidelines:

  You can double-click on most Timeline elements to view the data properties they represent.

  You can right-click most Timeline elements and window backgrounds to see a menu of commands. Each menu includes commands applicable to the selected window or element.

  Timeline’s special displays are only available when certain elements are selected. The SV Plot menu only appears as a menu command or active toolbar button when a Satellite icon is selected. Similarly, the DOP Plot and Skyplot commands are only available in menus and toolbar buttons when an occupation, survey, or ephemeris icon is selected.

For more information, see these topics:

  Viewing the Previous or Next Occupation

  Timeline Data Folders

  Timeline Menus

  Timeline Toolbars

  Additional Timeline Displays

  Timeline Properties Dialogs

  Timeline Commands


To plot raw satellite tracking information

 Overview and More Information

Raw satellite tracking information is plotted in SV Plot by selecting buttons from the dialog bar or options for the View / Data menu. In addition to plotting the data, the plots can be printed and the information collected from the satellite can be exported to a file to document the plot.

To plot satellite tracking data:

1.	To view Timeline, do one of the following:

  Select View / Timeline.

  Press Alt+VI.

The Timeline View Area appears.

2.	Click a data folder.

Data folders appear in the control bar located in the lower-left corner of the Timeline Viewing Area and show a [image] symbol when closed and a [image] symbol when opened. Data folders display the model and serial number of the receiver used to collect the data. When opened, icons appear for all satellites tracked during the occupation time span.

NOTE: In lieu of opening individual folders, the Expand All command can be used to open all data folders.

3.	Double-click a Satellite Icon.

The Satellite icon is highlighted, and the SV Plot window appears.

4.	To plot the data, do one of the following:

  Click the desired button on the dialog bar.

  Select the desired plot commands from the View / Data menu.

Once the plot is displayed, you can perform these actions:

To display plot measurements:

  Move the mouse cursor across the plot to the desired location, and read the measurement and time information in the status bar. The value recorded at the mouse location and the time when the data was collected appears in the status bar.

To plot a different plot in the same window:

  Select the desired plot command from the dialog bar or View / Data submenu.

The selected data is plotted in the same plot window along with the first plot.

To print the plot:

1.	Do one of the following:

  Select File / Print.

  Press Ctrl+P.

  From the toolbar, click [image].

The Print dialog appears.

2.	Select the desired options.

3.	Click OK.

The plot is printed.

To print the plot to a file:

1.	Do one of the following:

  Select File / Print.

  Press Ctrl+P.

  From the toolbar, click [image].

The Print dialog appears.

2.	Select the Print to File option.

3.	Click OK.

The plot is printed to a file. Many programs can import graphic data printed to a file. This is useful for including plots in reports.

To print tabular data:

1.	Do one of the following:

  Select File / Export.

  Press Alt+FE.

The File Export dialog appears.

2.	Select the directory and file name for storing the file.

The satellite tracking information used to generate the plot is written to a text file (*.txt) and stored in the selected directory. The data is written to the file in tabular format. If multiple plots were displayed in the same SV Plot window, one column of tabular data is included for each type of plot.

NOTE: Additional plot windows can be opened using the File / New Plot command. Each window can display separate sets of plots. You can minimize and maximize windows and perform other common actions to control the windows displayed in SV Plot.


To print the Timeline view area

 Overview and More Information

The contents of the Timeline view area can be printed in portrait or landscape mode.

NOTE: Before printing, adjust the size of the viewing area. Only the data currently appearing in the viewing area is printed.

To print the Timeline view area:

1.	To view Timeline, do one of the following:

  Select View / Timeline.

  Press Alt+VI.

2.	Click the background of the control bar, Time Span Viewer, or Time Ruler.

3.	To view the Print dialog, do one of the following:

  Select File / Plot/Print.

  Press Ctrl+P.

The Print dialog appears.

4.	To print the view area, do one of the following:

  To print the view area in Portrait mode, click OK.

  To print the view area in Landscape mode, click Properties, click Landscape, click OK twice.

The Timeline view area is automatically scaled to fit the width or length of the paper and is printed.


To process baselines

 Overview and More Information

Individual baselines or sets of baselines can be selected for processing.

To process all baselines:

1.	Open a project containing raw GPS data files.

2.	Click the Graphics window background.

You must click an area where no data is plotted. This action deselects all selected items. When no baselines are selected in the Graphics window, the baseline processor automatically selects all potential baselines for processing.

3.	To process baselines, do one of the following:

  From the Survey menu, select Process GPS Baselines.

  From the Trimble Survey Group in the project bar, select Process GPS Baselines.

  From the process group in the project bar, select Process GPS Baselines.

  Press F9.

NOTE: The GPS processing session can be canceled at any time by pressing Cancel.

Status information appears in the status bar as the GPS processing session continues. These statistics appear:

  The progress indicator on the left side of the status bar monitors the progress of each baseline processing solution.

  The second indicator displays messages generated by the GPS processor. Individual baseline starting points and ending points are displayed as the session continues.

  The number of files to process and the remaining number of baselines to process appear in the third status bar indicator from the right. This indicator reads Pending after all baselines are processed and before Save is clicked to store the solutions in the project.

  The status indicator on the far right summarizes the number of accepted and rejected baseline solutions.

As the GPS processing session continues, the processing results of each of the selected baselines appear in summarized form in the GPS Processing list. Accepted baseline solutions are identified by a check mark appearing in the left column of the GPS Processing list.

Individual baselines with flagged solutions are marked with red flags in the Graphics window.

To process a selection of baselines:

1.	From the Graphics window, select the baseline(s) you want to process using one of these techniques:

  Drag a selection rectangle around a group of baselines.

  Hold down the Ctrl key while clicking multiple baselines.

TIP: You can deselect a baseline by holding down the Ctrl key and clicking the baseline a second time.

2.	To process baselines, do one of the following:

  From the Survey menu, select Process GPS Baselines.

  From the Trimble Survey Group in the project bar, select Process GPS Baselines.

  From the process group in the project bar, select Process GPS Baselines.

  Press F9.

The GPS Processing dialog appears and processing begins.

Once baselines are processed, you can view the GPS Baseline Processing report and analyze the results of individual baseline solutions. For more information, see Analyzing GPS Baseline Processing reports.

After reviewing the report data for individual solutions, you can save the baseline solutions.

NOTE: After processing baselines and closing the GPS Processing dialog, you can double-click on the Warning Flag indicator in the Survey view status bar. The double-clicking action opens the Properties window with the selection of baselines which have warning flags associated with them. You can open the Baseline folders in the Selection list to identify why these baselines were flagged. The Warning page will identify if the baseline failed the Ratio, RMS, or Reference Variance acceptance criteria and other reasons for flagging the baseline such as loop closure failure. Understanding why baselines are flagged may be useful in preventing the same problem from occurring again. For more information, see Analyzing GPS Baseline Processing reports.

There are many considerations for processing GPS data. For more information about GPS baseline processing, see these topics:

  Determining Potential Baselines

  Selecting Baselines to Process

  Selecting a GPS Processing Style

  Starting the Baseline Processor

  Viewing the Processing Results

  Saving the Processing Results

  Reprocessing Baselines


To reprocess problematic baselines

 Overview and More Information

This troubleshooting technique is dependent upon the length of the observation session time. If the baseline in question has enough data, and a sufficient number of satellites in view, shorten the occupation time at the beginning, or at the end of the session. This procedure is especially useful if the data at the beginning or the end of the session is noisy, or filled with cycle slips.

To reprocess the baseline:

1.	To view Timeline, do one of the following:

  Select View / Timeline.

  Press Alt+VI.

2.	Expand the data folder containing the survey data.

3.	Right-click on the GPS observation.

4.	Select Properties. The GPS Observation Properties dialog appears.

5.	Type the new Start or End time.

6.	Click OK.

7.	Click the problematic baseline.

8.	To process the baseline, do one of the following:

  From the Survey menu, select Process GPS Baselines.

  From the Trimble Survey Group in the project bar, select Process GPS Baselines.

  From the process group in the project bar, select Process GPS Baselines.

  Press F9.

The individual baseline solution is recomputed and the results appear in the Baseline Processing dialog.


To select occupations in Timeline

 Overview and More Information

The Graphics window and Timeline are interconnected. Consider these guidelines when selecting elements from the Graphics window or Timeline View Area:

  If you select occupations in Timeline, the selected points are also selected in the Graphics window.

  If you select a baseline in the Graphics window, Timeline selects the two occupations making up the baseline.

  If you select a point in the Graphics window, Timeline selects all occupations associated with the point.

A color coding scheme is used to identify the various types of occupations and data segments appearing in the Time Span Viewer. For more information, see Color Coding Scheme.

To select occupations in Timeline:

  Click the occupation.

The occupation is highlighted to show it is selected.

To select occupations by selecting a baseline in the Graphics window:

  Click the baseline in the Graphics window.

The two occupations associated with the baseline are selected in the Time Span Viewer.

To select occupations by selecting a point in the Graphics window:

  Drag a selection rectangle around the point.

The occupation associated with the point is selected in Time Span Viewer.

TIP: Observations and points can also be selected from the Properties window and vice versa. You can also leave the Properties window open while working in Timeline or the Graphics window to view the properties of selected entities.


To set up the GPS Baseline Processing report

Sections of the GPS Baseline Processing report can be enabled or disabled to control the content of the report.

To setup the report:

1.	To view the GPS Baseline Processing Report Setup dialog, do one of the following:

  Select Report / Setup / GPS Baseline Processing Report.

  Press Alt+RSO.

The GPS Baseline Processing Report Setup dialog appears.

2.	Select or clear check boxes to control the sections included in the GPS Baseline Processing report.


To start GPS processing

 Overview and More Information

To start GPS processing:

1.	In the Survey view, select the desired baselines. If none are selected, all potential baselines are processed.

2.	Do one of the following:

  From the Survey menu, select Process GPS Baselines.

  From the Trimble Survey group in the project bar, select Process GPS Baselines.

  From the Process group in the project bar, select Process GPS Baselines.

  Press F9.

The GPS Processing dialog opens and processing begins.

NOTE: To cancel the GPS processing session at any time, click Cancel.

Status information appears in the status bar as the GPS processing session continues. The following statistics appear:

  The progress indicator on the left side of the status bar monitors the progress of each baseline processing solution.

  The second indicator displays messages generated by the GPS processor. Individual baseline start and end points are displayed as the session continues.

  The number of files to process, and the remaining number of baselines to process, appear in the third status bar indicator from the right. This indicator reads Pending after all baselines are processed and before Save is clicked to store the solutions.

  The status indicator on the far right summarizes the number of accepted and rejected baseline solutions. The acceptance criteria are set in the GPS Processing Styles dialog.

As the GPS processing session continues, the processing results of each of the selected baselines appear in summarized form in the GPS Processing list. A check mark in the left column of the GPS Processing list identifies accepted baseline solutions. No check mark appears when a baseline fails the quality acceptance test criteria.

Flagged baselines are passed and their solutions are saved. Examine these once the GPS processing session ends to determine why they did not pass the quality acceptance criteria. Flagged baselines are marked with red flags in the graphics window.

To reject individual baselines before saving the processing session.

1.	Select the desired baseline solution from the GPS Processing list.

2.	Clear the check box in the left column.

To view a GPS Baseline Processing report for individual baseline solutions:

1.	Select the desired baseline solution from the GPS Processing list.

2.	Click Report. The GPS Baseline Processing report appears.

For more information, see GPS Baseline Processing report.

3.	If necessary, repeat these steps to view additional reports.

TIP: You can view the GPS Baseline Processing report for a baseline after GPS processing. In the graphics window, select the desired baseline(s), and then select Report / GPS Baseline Processing Report.

All accepted baseline solutions can be saved to the project.

The Overwrite Duplicate Baseline Solutions check box controls how baselines are saved after reprocessing. The default is selected, which means existing solutions are overwritten. If the check box is cleared, the new solution is added to the project and the old solution is retained. When this occurs, the new solution becomes the active solution and the previous solution becomes inactive. The Properties window can be used to change a previous solution back to be the active solution.

The Overwrite Duplicate Baseline Solution check box applies only to baselines that are processed more than one time. It does not affect baselines between the same two points that are computed from GPS data collected at a different time or on a different day. It is recommended that you always overwrite duplicate baseline solutions.

To save baseline solutions:

  Click Save.

The accepted baseline solutions are saved to the project.

To cancel a GPS processing session:

  Click Cancel.

There are many considerations for processing GPS data. For more information about GPS baseline processing, see these topics:

  Determining Potential Baselines

  Selecting Baselines to Process

  Selecting a GPS Processing Style

  Starting the Baseline Processor

  Viewing the Processing Results

  Saving the Processing Results

  Reprocessing Baselines


To troubleshoot the elevation mask setting

 Overview and more information

Use this troubleshooting procedure if baseline statistics did not improve after disabling selected satellites or GPS observations data. Raising the elevation mask may remove noisy data and improve baseline statistics. Use a trial-and-error approach to raising the elevation mask angle. Try increasing the angle in one degree increments to avoid losing good data.

To evaluate the elevation:

1.	To view Timeline, do one of the following:

  Select View / Timeline.

  Press Alt+VI.

Timeline appears.

2.	Click the [image] symbol of the desired data folder to see individual satellites associated with calculating the problematic baseline.

3.	Right-click a Satellite icon.

4.	Select SV Plot.

5.	Click Elevation to view the change in elevation for the satellite.

6.	Repeat for all satellites associated with the baseline to determine if raising the elevation mask is improving processing results.

To raise the elevation:

1.	To view the GPS Processing Styles dialog, select Survey / GPS Processing Styles. 	The GPS Processing Styles dialog appears.

2.	Select the style from the list.

3.	Click Edit. The Edit Style dialog appears.

4.	In the Elevation Mask field, enter the new elevation mask angle.

5.	Click OK one or more times until the dialogs close.

6.	Click the baseline.

7.	To process the baseline, do one of the following:

  Select Survey / Process GPS Baselines

  Press F9.

The individual baseline is reprocessed

8.	Check the results.

Verify if this troubleshooting procedure improved baseline statistics.


To use observed met data for GPS processing

The Use Observed Met Data check box control is used to specify that observed met data should be used during baseline processing for tropospheric corrections.

NOTE: The following steps assume the Edit Advanced Style dialog is displayed.

To enable or disable the use of Met data:

1.	Select the Tropo tab. The Tropo style settings appear.

2.	Set the Use Observed Met Data check box to select the type of meteorological data applied when computing GPS processing solutions. Met (Meteorological) data consists of relative humidity, barometric pressure, and temperature. Consider these guidelines:

  When this check box is selected, the observed meteorological data in the GPS data file (.dat), or imported with a RINEX file, is used to model the troposphere when computing the tropospheric zenith delay. By default, this check box is selected.

  Clear this option to use standard met values in place of the recorded met data.

NOTE: When recording Met data in the field, it is very important to use high-quality instruments that have been calibrated to ensure proper readings. Using Met data obtained with non-calibrated or poor-quality instruments can degrade the baseline solution.


To view ephemeris properties in Timeline

 Overview and More Information

Information derived from the broadcast ephermides collected from individual satellites during data collection sessions is available in Timeline. The applicable data folder must be opened before viewing the information.

Ephemeris information in the dialog is derived from the broadcast ephemeris and cannot be edited. The messages in the URA and Health fields are of special interest, since they are indicators of the quality of data transmitted from the satellite.

To view ephemeris properties, do one of the following:

  Double-click the Ephemeris icon.

  From the Timeline toolbar, click [image].

The Satellite Ephemeris Properties dialog appears.


To view occupation properties in Timeline

 Overview and More Information

The properties of Continuous Segments and Static Occupations can be viewed in the Occupation/Data Segment Properties dialog. The dialog options are automatically updated to reflect the selected occupation type.

To view Occupation properties:

1.	Double-click the desired Occupation element. The Occupation/Data Segment Properties dialog appears.

2.	After viewing the properties, click OK.

NOTE: You can also edit selected properties, including the Segment Type, Start and End Time of the Occupation, and the antenna properties.


To view GPS observation properties in Timeline

 Overview and More Information

The Satellites filter is turned on by default when Timeline appears. You can turn the filter off to hide GPS Observations.

To filter GPS observations from the toolbar:

  From the Timeline toolbar, click [image].

The GPS observations are hidden if displayed or revealed if hidden.

To filter GPS observations from the Time Span Viewer:

1.	Right-click the Time Span Viewer background.

2.	Select View Filters / Satellites.

The GPS observations are hidden if displayed or revealed if hidden.


To view the next or previous survey segment in Timeline

 Overview and More Information

The Next and Previous commands, also represented as blue arrow buttons on the Timeline toolbar, are used to pan the Time Span Viewer to the next or previous occupation's start or end point. These commands are especially useful when the timeline becomes extremely long, making it difficult to pan between occupations effectively.

To use the Next or Previous commands:

1.	Select the Occupation element in the Time Span Viewer.

2.	To select the Next or Previous command, do one of the following:

  Right-click the Occupation, and select Next or Previous.

  From the Timeline toolbar, click [image] or [image].

If Next is select, the Time Span Viewer pans to the end point of the next occupation. If Previous is selected, the Time Span Viewer pans to the previous occupation.

NOTE: The Occupation/Data Segment Properties dialog includes two spin buttons. The left spin button behaves like the Previous command and the right button behaves like the Next command. These buttons allow you to pan the Time Span Viewer to the next or previous occupation and view the properties of each occupation at the same time.

TIP: You can also use the Properties window to pan the Time Span Viewer by selecting an observation or point associated with an occupation. Selecting an observation or point from the Properties window automatically selects the applicable Survey element and pans the Time Span Viewer to the associated occupation element. If you leave the Properties window displayed while working in Timeline, you can view the properties of the observations and points associated with occupations.


To view baseline statistics

 Overview and More Information

Baseline statistics can be viewed in several ways. They can be viewed both during and after completing a GPS processing session.

To view baselines statistics from the GPS Processing dialog:

1.	Start GPS processing.

The GPS processing dialog appears and the processing session beings. As the processor continues, each solution appears in the GPS Processing lists. For more information, see Processing Baselines.

2.	Examine the Ratio, Ref Variance, and RMS columns for each baseline.

These columns show the results of the Ratio, Reference Variance, and RMS tests. If the reported results fall within the acceptance criteria defined for the GPS processing style, the baseline solution is accepted and a check mark appears in the first column of the list. No check mark appears in the first column when any one of the enabled tests report poor results.

NOTE: Flagged baselines are also accepted into the project, but a red warning flag appears in the Graphics window. The properties of flagged baselines should be examined to determine why the baseline did not pass the acceptance criteria, and appropriate actions should be taken to correct any deficiencies. For more information, see Properties window.

3.	To view the GPS Baseline Processing report for any solution, select a solution from the list and click Report. The GPS Baseline Processing report appears.

TIP: You can also double-click the baseline to view the report. You do not have to wait until the GPS processing session is completed before viewing the report. Processing will continue as you read reports for individual baselines.


To view the GPS Baseline Processing report

 Overview and More Information

The GPS Baseline Processing report for a baseline can be viewed as soon as the baseline is processed and the results appear in the GPS Processing list. The processor will continue to process baselines while you review the GPS Baseline Processing report.

To view the GPS Baseline Processing report:

1.	To view the GPS Baseline Processing report, do one of the following:

  Double-click a baseline solution in the GPS Processing dialog.

  Select a baseline, and click Report.

The GPS Baseline Processing report appears.

2.	Scroll through the report to examine the data.

Examine the details of the baseline solution that are not available in the one-line summary.

Verify the station information in the solution against the information in your field notes. Pay particular attention to:

  Station names

  Antenna heights, types and measurement methods

  Start and stop times

Check the Satellite Phase Tracking Summary at each station for breaks or gaps in the L1 or L2 signal. A solid line indicates a clean signal. A gap or break in the line indicates a cycle slip or satellite signal loss. Tick marks indicate when the receiver picked up the satellite signal after a cycle slip.

Check the combined Satellite Phase Tracking Summary. The gray shading indicates the measurements actually used in the baseline solution.

Check the Residual plots for each satellite. These show the RMS for each satellite used to determine the baseline solution.


    Process GPS Baselines command

More Information

How to ...	Dialog
Select this command to start a GPS processing session:

  Select Survey / GPS Processing. The GPS Processing dialog appears and the GPS processing session begins.


    GPS Baseline Processing Report command

More Information

How to ...	See also
Select this command to view the GPS Baseline Processing report:

1.	Select the baseline(s) you want to report.

2.	Select Report / GPS Baseline Processing Report. The GPS Baseline Processing report appears.

This report shows the results of the previous GPS processing session. Use it to analyze the results for the baseline processing solutions.

NOTE: The GPS Baseline Processing report is also accessible from the GPS Processing dialog. You can select individual baseline solutions from the GPS Processing list, and click Report to view the baseline’s report.


    Timeline command

More Information

 See also

To open the Timeline view area, do one of the following in the Survey view:

  Select View / Timeline.

  From the toolbar, select [image].

The Timeline view area appears at the base of the graphics window.

Timeline displays information about the GPS measurements in a project in a graphical, time-based format. Each piece of data is represented at its appropriate position on a timeline. Timeline is only available in the Survey view.


Edit Style dialog - Overview
    Edit Style dialog − Overview

More information

 How to ...

Overview

Use this dialog to determine how GPS data is processed.

To open the Edit Style dialog:

1.	Select Survey / GPS Processing Styles. The GPS Processing Styles dialog appears.

2.	Select a style from the list.

3.	Click Edit. The Edit Style dialog appears.

Click Advanced when you need to access more advanced style controls for fine-tuning the operation of the GPS baseline processor. The Edit Advanced Style dialog appears.

Elevation Mask

Edit this field to set the minimum satellite elevation for GPS baseline processing. This setting overrides the elevation mask used to collect observation data in the field.

Consider these guidelines:

  When computing baseline processing results, the Trimble Geomatics Office software only uses those satellites above this elevation. You must enter this value in degrees. The default is 13 degrees.

  You can set this value higher or lower than the elevation mask used to collect observation data in the field, but it is usually set to a higher value. Setting the value lower than that used in the field has no effect on processing.

  This setting is useful when several receivers are used to collect observation data and the elevation masks are not set to the same settings. This field overrides those elevation mask settings and uses a constant elevation mask for baseline processing.

  Increasing the elevation mask removes lower elevation satellites from GPS processing results. These satellite signals can be affected by noise resulting from possible obstructions and longer paths through the troposphere.

  Increasing the elevation mask by too much can influence GPS processing results by decreasing the number of satellites available in the constellation.

Ephemeris

From this list, select the type of ephemeris to use for baseline processing:

  Broadcast − the default for most processing. The broadcast ephemeris is transmitted periodically by each GPS satellite, typically on an hourly basis. The ephemeris contains the orbital parameters for the satellite.

  Precise − improves baseline accuracy. Often a precise ephemeris can also help you to achieve fixed ambiguity solutions on long baselines. To use this option, one or more precise ephemerides must be imported into the project.

To use precise ephemeris for baseline processing, the precise ephemeris files imported into the project must contain at least eight sets of SV positions both before and after the time interval of the data being processed. Since most precise ephemeris files provide SV positions every 15 minutes, this means that you must have precise ephemeris coverage for two hours before and two hours after the start of your survey. If you are surveying near 0:00 UTC, you may need to obtain precise ephemeris files from two days to ensure proper coverage.

Precise ephemeris files used to contain information for all GPS satellites for an entire week. The most commonly available files now, however, only contain information for a single day. Precise ephemeris files can be obtained in SP3 and EF18 format. The Trimble Geomatics Office software can use either format.

Precise ephemeris files are available from:

  National Geodetic Survey (NGS)

  Center for Orbit Determination in Europe (CODE)

  European Space Agency (ESA)

  Scripps Institute Observatory (SIO)

  Canadian Department of Energy, Mines, and Resources (EMR)

  NASA's Jet Propulsion Laboratory (JPL)

  U.S. Naval Observatory (USNO)

Solution Type

From this list, select the solution type for the final pass of the baseline processor.

The baseline processor progresses through an ordered sequence of solutions for each baseline based on the types of observations available and the settings in the active processing style. Processing typically begins with a Code solution, followed by a triple difference and several double-differenced carrier-phase solutions. The final pass solution is selected here and represents the best solution that can be obtained given the set of observations and controls.

The most common solutions types are L1 fixed for short baselines and Iono-free fixed solutions for most other solutions. If you process very long lines, Iono-free float solutions may be the best possible solution.

The following options are available:

  Code − use this option to perform a code-only solution. If you select this option, the GPS processor stops at the code solution pass.

  Float − use this option to generate a float solution without solving for fixed-integer ambiguities. In some instances the reduction in processing time could prove beneficial. This option might be useful, for example, when processing very long baselines where a float solution may be the only achievable solution. Selecting Float as the Solution Type prevents the GPS processor from performing what could be a long integer search.

Other controls used to specify the generation of float solutions in a different way include:

  Maximum Baseline Length to Attempt a Fixed Solution

  Maximum integer search time

Both of these controls are found in the Edit Advanced Styles dialog.

  Fixed − use this option to perform a fixed-integer solution. This is the default and also the preferred solution.

NOTE: When creating a GPS processing style that specifies a Code-only final Solution Type, you should edit the Acceptance criteria group in the Quality tab as well. Code only solutions typically are flagged based on the criteria supplied in the Trimble Default processing style. A Code-only processing style with appropriate Acceptance Criteria will ensure that baseline processing results are evaluated properly.

Advanced

Click Advanced to view or edit the advanced controls in the active GPS processing style.


Edit Advanced Style dialog - Static tab
    Edit Advanced Style dialog − Static tab

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 How to ...

Edit these controls to change the settings used for the processing of static and FastStatic baselines

To view the Static tab of the Edit Advanced Style dialog:

1.	Select Survey / GPS Processing Styles. The GPS Processing Styles dialog appears.

2.	Select a style from the styles list.

3.	Click Edit. The Edit Style dialog appears.

4.	Click Advanced. The Edit Advanced Style dialog appears.

5.	Select the Static tab.

Minimum Baseline Observation Time

Edit this field to set the amount of overlap required between two simultaneous station occupations before the resulting baseline will be considered for processing. This controls the addition of potential baselines to a project.

By default the baseline processor requires 120 seconds of simultaneous data to process a baseline between receivers. This removes accidental overlap between multiple rovers.

Maximum Baseline Length to Attempt a Fixed Solution

Edit the fields in this group to specify the maximum length of a baseline for which the baseline processor will attempt to produce a fixed solution. Baselines longer than the values specified here receive float solutions.

These fields are available:

 Using Broadcast Ephemeris − edit this field to set the maximum baseline length considered when computing fixed GPS processing solutions using a broadcast ephemeris. The GPS processor does not compute a fixed solution if the maximum baseline length is greater than this value. The default is 200 kilometers.

 Using Precise Ephemeris − edit this field to set the maximum baseline length considered when computing fixed GPS processing solutions using a precise ephemeris. The GPS processor does not compute a fixed solution if the maximum baseline length is greater than this value. The default is 2000 kilometers.


Edit Advanced Style dialog - Kinematic tab
    Edit Advanced Style dialog − Kinematic tab

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Edit these controls to change the settings used for the processing of kinematic baselines.

To view the Kinematic tab of the Edit Advanced Style dialog:

1.	Select Survey / GPS Processing Styles. The GPS Processing Styles dialog appears.

2.	Select a style from the styles list.

3.	Click Edit. The Edit Style dialog appears.

4.	Click Advanced. The Edit Advanced Style dialog appears.

5.	Select the Kinematic tab.

Minimum reference observation time

Edit this field to define the minimum amount of observation time required for an occupation to be considered a Kinematic reference station relative to other occupations in the processing session.

Consider these guidelines:

  The value in this field is intended to prevent the GPS processor from processing overlaps of common observations imported into the project from several data files. These observations are collected by two or more rovers which occupied two points simultaneously. If a rover remains stationary at a point longer than this minimum time, the rover is treated as a reference point and the common observation data collected by other rovers is processed relative to this point.

  Consider a Kinematic survey with a single base receiver and two roving receivers. Without this minimum reference observation time, the GPS processor would attempt to process not only the data between the rovers and the base, but also the data between the two rovers.

  The default is 600 seconds. The default minimum reference observation time tells the GPS processor that only occupations in excess of 600 seconds, or 10 minutes, are considered reference points.

  Set this field to zero to process baselines between roving receivers.

Minimum static initialization observation time

Edit this field to change the minimum amount of observation time required for a baseline to be used as a static initialization for a particular Kinematic processing segment.

Consider these guidelines:

  The default setting requires that a baseline be occupied for at least 120 seconds, or 2 minutes, before it is used for any further initialization purposes.

  Baselines exceeding this value are processed as static baselines and saved in the project for static initialization.

Minimum known point initialization ratio

Edit this field to change the minimum acceptable ratio used for known point initialization during Kinematic GPS processing.

Known point initialization begins by inversing between two known points. The information derived from this inverse is treated as if it were a fixed baseline. The baseline processor then holds the baseline derived from the inverse fixed, and solves only for the satellite ambiguities. This step includes an integer search, similar to that done in a static or FastStatic solution.

The ratio used to judge the success of the search is the same as that from a normal fixed integer solution. If the ratio from the search is greater than the Minimum Known Point Initialization Ratio, the GPS processor accepts the results and uses them to initialize for subsequent Kinematic processing.

The default Minimum Known Point Initialization Ratio is 3.0. This value is higher than the normal cutoff value of 1.5 for static and FastStatic solutions. It is higher because the processor is only solving for satellite ambiguities, and since fewer variables are involved, the ratio is expected to be higher.

Minimum OTF processing time

Edit this field to change the minimum time duration required for the GPS processor to attempt to resolve integer ambiguities on-the-fly.

Consider these guidelines:

  The receiver must run continuously for 200 seconds and maintain lock on at least four satellites to process the on-the-fly (OTF) initialization. The default is 200 seconds with five satellites in view.

  In the absence of any static initialization information, the GPS processor attempts to resolve the integer ambiguities using any portion of data with at least four satellites in the constellation, each with epochs of at least 200 seconds in duration. Since the satellite constellation continuously changes, the data for the best combination of four satellite is processed, and not necessarily the same four satellites for the entire occupation.

  The GPS processor uses the OTF initialization technique if any ambiguities remain after performing all static and fixed baseline initializations. The GPS processor does not use OTF initialization on kinematic processing segments shorter than this time interval. These segments must be initialized with static or fixed-baseline initialization techniques.


Edit Advanced Style dialog - Quality tab
    Edit Advanced Style dialog − Quality tab

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Edit these controls to change the identification and editing out of marginal data and solutions while processing, and before saving the processing results to the project. The controls on this page are used to identify which baseline solutions are passed, flagged, or failed.

To view the Quality tab of the Edit Advanced Style dialog:

1.	Select Survey / GPS Processing Styles. The GPS Processing Styles dialog appears.

2.	Select a style from the styles list.

3.	Click Edit. The Edit Style dialog appears.

4.	Click Advanced. The Edit Advanced Style dialog appears.

5.	Select the Quality tab.

Acceptance Criteria

Edit the fields in this group to change the acceptance criteria that are used to assign baseline processing solutions a Pass, Flag, or Fail status. These criteria also determine which baseline solutions, by default, should be saved in the project after processing.

Consider these guidelines:

 Flag and Fail fields are available for RMS, Ratio and Reference Variance. For information about these tests, see the following topics:

  If RMS check box

  If Ratio check box

  If Reference Variance check box

 Separate criteria can be specified for single- and dual-frequency baseline solutions. The use of single- or dual-frequency acceptance criteria is determined by a combination of the type of GPS measurements available, the Solution Type selected in the Active GPS Processing Style, and the final solution as determined by the baseline processor itself.

 The acceptance test can be based on any combination of checks using RMS, Ratio and Reference Variance. The default is to use all three of these quality parameters to determine the pass/flag/fail status. If more than one of the quality factors are used together, the status is based on the worst condition. For example, if Ratio and Reference Variance pass, but RMS fails, the baseline receives a fail status. The default is to use all three tests.

NOTE: It is not necessary to modify the acceptance criteria for most survey applications. The exception, however, is for code-only final pass solutions. Code-only solutions typically are flagged based on the criteria supplied in the Trimble default processing style. It is recommended that you set up a Code-only processing style with appropriate acceptance criteria if you routinely process Code-only final pass solutions.

Edit Multiplier

Edit this field to change the multiplier used to compute the cut-off value for removing outliers from successive GPS processor iterations.

The baseline processor solves baselines through a series of successive iterations. In each iteration the processor flags and removes data outliers from the solution. This is done by computing an observation residual for the current solution on an epoch-by-epoch basis. Each observation residual is then compared to a cut-off value to determine whether or not that observation is an outlier.

The cut-off value is the overall RMS for all observation residuals multiplied by the Edit Multiplier. If outliers are discovered, they are flagged and removed from the next processor iteration. A new overall RMS of all observation residuals is computed for each iteration, and this new value is used as the basis for the cut-off value used to flag and remove subsequent observations.


    If RMS check box

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 Dialog

This check box controls the use of RMS in determining acceptance of baseline processing solutions.

RMS is a measure of noise in the measurements and smaller values for RMS are considered better. Values of RMS that are less than the flag value contribute to a pass status. Values that are greater than the flag value, but less than the fail value, contribute to a flag status. Values that are greater than the fail value cause the baseline to fail. If this check box is clear, RMS is not considered when determining acceptance

Two pairs of fields are included for the RMS test; the Single Frequency Flag and Fail fields and the Dual-Frequency Flag and Fail fields. The GPS processor uses the values in only one set of these fields when performing the RMS acceptance test. The set of fields used is determined by the Solution Type selected for the GPS processing style.

Acceptance can be based on any combination of checks using RMS, ratio, and reference variance. The default is to use all three of these quality parameters to determine the pass/flag/fail status. If more than one of the quality factors are used together, the status is based on the worst condition. For example, if ratio and reference variance pass, but RMS fails, the baseline is given fail status.


    If Reference Variance check box

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This check box controls the use of Reference Variance in determining acceptance of baseline processing solutions.

The reference variance is a measure as to how well the baseline processor estimates the expected error. Ideally the reference variance should be 1.0. Values less than 1.0 indicate that less error was encountered than expected. Values more than 1.0 indicate that more error was encountered than expected. The test for acceptance based on reference variance only looks for the second case, where more error was encountered than expected.

Values of reference variance that are less than the flag value contribute to a pass status. Values that are greater than the flag value, but less than the fail value, contribute to a flag status. Values that are greater than the fail value cause the baseline to fail. If the check box is clear, reference variance is not considered when determining acceptance.

Two pairs of fields are included for the Reference Variance test—the Single-Frequency Flag and Fail fields and the Dual-Frequency Flag and Fail fields. The GPS processor uses the values in only one set of these fields when performing the test. The set of fields used is determined by the Solution Type selected for the GPS processing style.

Acceptance can be based on any combination of checks using RMS, ratio, and reference variance. The default is to use all three of these quality parameters to determine the pass/flag/fail status. If more than one of the quality factors are used together, the status is based on the worst condition. For example, if ratio and reference variance pass, but RMS fails, the baseline is given fail status.


    If Ratio

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This check box controls the use of Ratio in determining acceptance of baseline processing solutions.

Ratio is a measure of how well the processor is able to determine fixed integer solutions and higher numbers are considered better. Values for ratio that are greater than the flag value contribute to a pass status. Values that are less than the flag value, but greater than the fail value, contribute to a flag status. Values that are less than the fail value cause the baseline to fail. If the check box is clear, ratio is not considered when determining acceptance. The ratio also is ignored if the final solution for the processing style is float or code.

Two pairs of fields are included for the Ratio test: the Single-Frequency Flag and Fail fields and the Dual-Frequency Flag and Fail fields. The GPS processor uses the values in only one set of these fields when performing the Ratio test. The set of fields used is determined by the Solution Type selected for the GPS processing style.

Acceptance can be based on any combination of checks using RMS, ratio, and reference variance. The default is to use all three of these quality parameters to determine the pass/flag/fail status. If more than one of the quality factors are used together, the status is based on the worst condition. For example, if ratio and reference variance pass, but RMS fails, the baseline is given fail status.


Edit Advanced Style dialog - Tropo tab
    Edit Advanced Style dialog − Tropo tab

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Edit these controls to change the selection and application of tropospheric models when processing baselines.

To view the Tropo tab of the Edit Advanced Style dialog:

1.	Select Survey / GPS Processing Styles. 	The GPS Processing Styles dialog appears.

2.	Select a style from the styles list.

3.	Click Edit. The Edit Style dialog appears.

4.	Click Advanced. The Edit Advanced Style dialog appears.

5.	Select the Tropo tab.

Model

Select from this list to choose a tropospheric correction model. The model compensates errors that are introduced when the signals pass through the troposphere. The amount of correction varies with respect to the satellite elevation.

These options are available:

  Hopfield − the Hopfield model is the default

  Goad-Goodman

  Saastamoinen

  Black − the Black model is unstable at low satellite-elevation angles and should not be used with an elevation mask less than 10 degrees

  Niell − the Niell model is latitude and seasonal dependent, in addition to being satellite elevation dependent

  None − select this option if you do not want to use a tropospheric model.

For more information about the models for correcting GPS signals passing through the troposphere, see the Bibliography.

Estimated Zenith Delay Interval

Edit this field to define a constant zenith delay time estimation interval, in hours.

Consider these guidelines:

  The number of hours must be entered as an integer value. The minimum recommended estimation interval is one hour. The default value is two hours. A value of zero (0) results in no zenith delay estimation. This field is not available when the tropospheric model is set to None.

  Since the troposphere is not as dynamic as the ionosphere, the signal delay over two hours is slow. If processing long baselines, and a storm front passes over one receiver and not the other, shorten the estimate interval. The default interval is 2 hours.

  For very long baselines over 50 kilometers, errors in broadcast ephemeris may result in inaccurate tropospheric parameter estimation. In this case, use a precise ephemeris.

  For baselines under approximately 10 kilometers, with data files shorter than about 2 hours in duration, there may be no advantage to estimating zenith delays. As the baseline length and observation periods increase, effects of the troposphere may become more significant.

Use Observed Met Data

Select this check box to specify that Met data collected in the field should be used when computing GPS processing solutions. Met (meteorological) data consists of temperature, pressure and relative humidity.

Consider these guidelines:

  When this check box is selected, the observed meteorological data  in the GPS data file (.dat), or imported with a RINEX file, is used to model the troposphere when computing the tropospheric zenith delay. By default, this check box is selected.

  Clear this option to use standard met values in place of the recorded met data.

NOTE: When recording Met data in the field it is very important to use high quality instruments that have been calibrated to ensure proper readings. Using Met data obtained with non-calibrated or poor quality instruments can degrade the baseline solution.


Edit Advanced Style dialog - Iono tab
    Edit Advanced Style dialog − Iono tab

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How to ...	See also
Edit these controls to change the application of ionospheric modeling when processing baselines.

To view the Iono tab of the Edit Advanced Style dialog:

1.	Select Survey / GPS Processing Styles. 	The GPS Processing Styles dialog appears.

2.	Select a style from the styles list.

3.	Click Edit. The Edit Style dialog appears.

4.	Click Advanced. The Edit Advanced Style dialog appears.

5.	Select the Iono tab.

Ambiguity resolution pass

Select the check box in this group to enable ionospheric modeling for the ambiguity resolution pass. The value entered in the Apply to all baselines longer than field determines the minimum baseline length for receiving ionospheric corrections.

The default correction is Iono Free for baselines longer than 10 kilometers that were observed using dual-frequency receivers. The Broadcast ionospheric model is used for baselines observed using single-frequency receivers. This option controls the use of ionospheric corrections during ambiguity resolution only. A separate control is available for the final pass ionospheric correction.

Final pass

Select the check box in this group to enable ionospheric modeling for the final pass. The value entered in the Apply to all baselines longer than field determines the minimum baseline length for receiving ionospheric corrections.

The default correction is Iono Free for baselines longer than 5 kilometers that were observed using dual-frequency receivers. The Broadcast ionospheric model is used for baselines observed using single-frequency receivers. This option controls the use of ionospheric corrections during the final pass only. A separate control is available for the ambiguity pass ionospheric correction.


Edit Advanced Style dialog - Events tab
    Edit Advanced Style dialog − Events tab

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Edit these controls to define the interpolation scheme and time offset used to compute event positions and times.

To view the Events tab of the Edit Advanced Style dialog:

1.	Select Survey / GPS Processing Styles. The GPS Processing Styles dialog appears.

2.	Select a style from the styles list.

3.	Click Edit. The Edit Style dialog appears.

4.	Click Advanced. The Edit Advanced Style dialog appears.

5.	Select the Events tab.

When a receiver logs an event, an event marker is placed in the file with the GPS measurements. This event marker includes a time tag indicating the time the event occurred. Since events rarely occur at the exact instant a data measurement is made, the GPS processor must compute receiver positions preceding and following the event, and then interpolate the position where the event occurred.

Interpolation method

Select one of these options to choose the linear or quadratic interpolation method to derive event positions when processing continuous kinematic data:

  Linear − select this option to apply a simple linear interpolation using positions derived from the baseline solutions both before and after the event occurred. A minimum of two points is required, and up to five points can be used for linear interpolation. Specify the number of points to use in the Number of points to fit field. The default is 2 points.

  Quadratic − select this option to apply a second-order, curve-fitting interpolation using positions derived from the baseline solutions both before and after the event occurred. A minimum of three points is required, and up to five points can be used for quadratic interpolation. Specify the number of points to use in the Number of Points to Fit field. The default is 3 points.

The interpolation and final time tag are controlled by the following options:

Number of points to fit

Edit this field to specify the number of points used to interpolate the position of an event.

The value can be used to control the number of points used by both the Linear and Quadratic interpolation method. The default value for the Linear Interpolation is 2 points, and for Quadratic Interpolation the default is 3 points. If an insufficient number of points is available, no interpolation will be done.

Maximum allowed missing epochs

Edit this field to control the maximum number of missing data measurement epochs allowed when computing the position of an event.

Consider these guidelines:

  The value entered in this field is used as a threshold or cut-off value for the event position interpolation method. If the number of missing data measurement epochs exceeds this value, the baseline processor will not attempt to interpolate an event position. The default is 0. This requires at least one data measurement both immediately before and after the time of the event.

  Increasing this value may help to recover an event that may not have received an interpolated position due to missing data. Consider a continuous kinematic survey where GPS measurements are collected at a rate of 1.0 seconds, and an event is triggered with a time tag of 245742.2 seconds. When the Maximum Allowed Missing Epochs is 0, continuous kinematic solutions at times 245742.0 and at 245743.0 must be available to interpolate the event position. If the continuous kinematic vector at time 245743.0 is missing, the event position is not interpolated. Increasing the Maximum Allowed Missing Epochs value to 1 allows the event position to be computed if a vector at time 245744.0 is available.

NOTE: Increasing this value excessively may decrease the accuracy of the interpolated position.

Time offset

Edit this field to apply a constant time offset between the recorded time of an event in the receiver and the actual time the event occurred.

Consider these guidelines:

  The time offset is entered in microseconds and may be positive or negative. Positive values delay the time of the event by adding the specified number of microseconds to the time tag. Negative values have the opposite effect.

  This value is set to zero by default. Change this value in cases where an external device is connected to the GPS receiver and a time offset exists between the reported event time and the actual occurrence of the event. Consider the case of an aerial camera where the shutter is tripped when photographing geographic terrain. The camera reports the event to the receiver when the shutter is tripped, resulting in a time offset dependent on the current shutter speed. If the shutter speed were set to 1000th of a second, the photograph would be captured 1000th of a second after the reported event. This field lets you compensate for time offsets of this nature.


Edit Advanced Style dialog - OTF Search tab
    Edit Advanced Style dialog − OTF Search tab

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How to ...	See also
Edit these controls to define the variables used to determine how OTF (On-the-Fly) searches are performed during ambiguity resolution passes.

To view the OTF Search tab of the Edit Advanced Style dialog:

1.	Select Survey / GPS Processing Styles. 	The GPS Processing Styles dialog appears.

2.	Select a style from the Styles list.

3.	Click Edit. The Edit Style dialog appears.

4.	Click Advanced. The Edit Advanced Style dialog appears.

5.	Select the OTF Search tab.

Search Method

Select one of the options in this group to control the ambiguity search method used during OTF (on-the-fly) kinematic processing:

  Optimal Search − select this option to use float values for all ambiguities estimated during initial GPS processing passes. After all estimates are computed, the float ambiguities are searched and fixed to integer values if possible. This is the default and it provides the most thorough examination of the data.

  Forward Sequential Search − select this option to use a forward-sequential search when processing data. Data is searched forward in time, beginning with the oldest recorded data and ending with the newest recorded data. Ambiguity searches occur as required (for example, when cycle slips are detected) as the data is progressively examined. Forward searches require less time than the Optimal Search.

  Backward Sequential Search − select this option to use a backward-sequential search when processing data. Data is searched backward in time, beginning with the newest recorded data and ending with the oldest recorded data. Ambiguity searches occur as required (for example, when cycle slips are detected) as the data is progressively examined. Backward searches require less time than the Optimal Search.

NOTE: The Sequential Control option determines how examined data is rejected.

Sequential Control

The Minimum search ratio field becomes available depending on the option in the Search Method group that you select. Use this field to define the rejection criteria used to fail data examined during OTF (On-the-Fly) searches.

You can edit the ratio used to reject searches of data examined during ambiguity resolution passes. When the ratio of the search is less the value entered in this field, the immediate search is rejected and the ambiguities for the search are not fixed until all other data is examined.


GPS Processing Styles dialog - Overview
    GPS Processing Styles dialog − Overview

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How to ...	Dialog
Overview

Use this dialog to select, view, edit, create, copy, rename, and delete the Active GPS Processing style. To open it:

  Select Survey / GPS Processing Styles.

The GPS Processing Styles dialog appears.

These controls are available:

Styles List

Selecting a style from this list makes it the Active Style. A GPS Processing Style must be made the Active Style before editing, copying, renaming or deleting it. The Active Style that is specified when this dialog is closed contains the controls that will be used during the next GPS processing session.

Edit

Click this button to view or edit the active style.

New

Click this button to create a new style. The New Style dialog appears. The Trimble Geomatics Office software’s default style settings are used. (Make sure you set up your own GPS processing style before deleting the Trimble default style.)

Copy

Click this button to copy the active style. The Copy Style dialog appears.

Rename

Click this button to rename the active style. The Rename Style dialog appears.

Delete

Click this button to delete the active style.


    New Style dialog

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How to ...	How to ...

Use this dialog to create a new GPS processing style.

To view the New Style dialog:

1.	Select Survey / GPS Processing Styles. The GPS Processing Styles dialog appears.

2.	Click New. The New Style dialog appears.

Name

Use this field to name the new style. Style names can include up to 255 characters, but shorter names are easier to find in the Styles list.

NOTE: After clicking OK to exit this dialog, the Edit Styles dialog appears with the style name in the dialog title. You can edit the general style settings on this dialog, and click Advanced to edit more advanced settings.


    Rename Style dialog

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Use this dialog to rename a GPS Processing Style.

To view the Rename Style dialog:

1.	Select Survey / GPS Processing Styles. The GPS Processing Styles dialog appears.

2.	Select the desired style from the list. The style name is highlighted.

3.	Click Rename. The Rename Style dialog appears.

Name

In this field, enter the new name for the style. Style names can include up to 255 characters, but shorter names are easier to find in the Styles list.


    Copy Style dialog

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Use this dialog to copy the Active GPS processing style to use as the source for a new style.

To view the Copy Style dialog:

1.	Select Survey / GPS Processing Styles. The GPS Processing Styles dialog appears.

2.	Select the style to copy from the list.

3.	Click Copy. The Copy Style dialog appears.

Name

Use this field to enter the name of the new style. Style names can include up to 255 characters, but shorter names are easier to find and read in the Styles list.

NOTE: After clicking OK to exit this dialog, the Edit Styles dialog appears with the style name in the dialog title. You can edit the general style settings on this dialog, and click Advanced to edit more advanced settings.


Edit Advanced Style dialog - Global tab
    Edit Advanced Style dialog − Global tab

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How to ...	Dialog	See also
Edit these controls to change the settings that are common to both static and kinematic processing.

To view the Global tab of the Edit Advanced Style dialog:

1.	Select Survey / GPS Processing Styles. The GPS Processing Styles dialog appears.

2.	Select a style from the list.

3.	Click Edit. The Edit Style dialog appears.

4.	Click Advanced. The Edit Advanced Style dialog appears.

5.	Select the Global tab.

Frequency type

Select an option from this list to choose the frequency type used during the final GPS processing pass:

  L1 − use this option to select the L1 carrier frequency. The default is L1.

  L2 − use this option to select the L2 carrier frequency.

  Wide-lane − use this option to select the wide-lane observable with a wavelength of approximately 86 cm, derived from subtracting the L1 and L2 carrier waves, or L1 – L2.

  Narrow-lane − use this option to select the narrow-lane observable with a wavelength of about 11 cm, obtained from adding the L1 and L2 carrier waves, or L1 + L2.

Consider these guidelines:

  When the Final Pass control is selected on the Iono tab, the Frequency Type specified here applies only to those baselines that are shorter than the cutoff value for the Iono Final Pass. Baselines that are longer than the cutoff value for the Iono Final Pass will get Iono Free solutions.

  The L2, Wide-lane, and Narrow-lane options do not apply if the project data includes observations for any single-frequency receiver. All data must be collected with dual-frequency receivers to use the L2, Wide-lane, and Narrow-lane options.

Maximum fixable cycle slip

Edit this field to set the maximum length of time of a cycle slip that the processor will attempt to be fixed during baseline processing.

Consider these guidelines:

  The GPS processor will attempt to fix cycle slips lasting less than or equal to the specified time limit.

  The GPS processor will not attempt to fix cycle slips lasting longer than the specified time. Instead, the GPS processor estimates separate ambiguities for each side of the cycle slip.

NOTE: The occurrence of cycle slips in the GPS measurements can be visually verified by using Timeline to examine the tracking for individual satellites. Cycle slips are graphically depicted as breaks in the L1 or L2 carrier spans along the timeline. For more information, see Timeline.

Maximum iterations

Edit this field to set the maximum number of iterations used by the baseline processor when computing baseline solutions. You can enter values from 1 to 99.

Consider these guidelines:

  An average of three GPS processing iterations are performed per solution to determine a baseline. If ten iterations are necessary, the baseline processing solution could be questionable.

  Ten iterations are usually sufficient. Do not change this field unless you understand its effect on least-squares adjustments.

Maximum integer search time

Edit this field to limit the amount of time the baseline processor spends doing an integer search. This control is used primarily for processing long baselines, especially when using data collected for a long period of time, such as 24 hours or more.

Consider these guidelines:

  Certain conditions, such as poor reference station coordinates, could cause the GPS processor to search literally billions of combinations, which might take several hours to compute. This time limit stops the search after the specified time elapses without completing the solution and proceeds with a float solution.

  The default is 30 minutes.


    GPS Processing dialog

More Information

How to ...	See also
The GPS Processing dialog shows:

  Processing status

  Number of baselines processed

  Number of baselines that have been accepted and rejected

To open the GPS Processing dialog:

1.	Select the set of baselines to process.

The baselines are highlighted in the Graphics window.

2.	To start baseline processing, do one of the following:

  From the Survey menu, select Process GPS Baselines.

  From the Trimble Survey Group in the project bar, select Process GPS Baselines.

  From the process group in the project bar, select Process GPS Baselines.

  Press F9.

The GPS Processing dialog appears and the baseline processing begins.

These controls are available:

GPS Processing List

Watch this list to monitor the results of the GPS processing session.

GPS Processing Status Indicators

The progress indicator on the left side of the status bar monitors the progress of each baseline processing solution. Clicking on this indicator will recenter the GPS Processing Dialog.

The second indicator displays messages generated by the GPS processor. Individual baseline starting points and ending points are displayed as the session continues.

The number of files to process and the remaining number of baselines to process appear in the third status bar indicator from the right. This indicator reads Pending after all baselines are processed and before Save is clicked to store the solutions in the project.

The status indicator on the far right summarizes the number of accepted and rejected baseline solutions.

Upon completing the processing session, the status bar displays Pending, indicating that the baselines have been processed but have not yet saved to the project. A one-line baseline summary is displayed in tabular format as each baseline is completed.

Stop / Save

Before processing is complete, you can click Stop to halt further processing without canceling the baseline processing session. After processing is complete, the Stop button becomes the Save button. Click Save to save the solutions that are selected in the GPS Processing list into the project. Selected baseline solutions are indicated by a check mark in the Use box. A save operation is also affected by the Overwrite Duplicate Baseline Solutions Control, as described below.

Cancel

Select this button at any time after GPS processing begins to abort the GPS processing session. Consider the following:

  If GPS processing is already completed when this button is clicked, a verification message appears. If you click Yes, the processed solutions are discarded and the dialog closes. If you click No, you are returned to the GPS Processing dialog.

  If GPS processing is under way when this button is clicked, processing stops after the current baseline solution is completed and a verification message appears. If you click Yes, the processed solutions are discarded and the dialog closes. If you click No, you are returned to the GPS Processing dialog.

Report

Select this button to view the GPS Baseline Processing report for the selected baseline solution. A baseline solution must be selected from the GPS Processing list before this button becomes available.

When the report dialog appears, you can navigate through the report to search for information. You do not have to wait until all baseline processing is completed before viewing a report. Reports can be generated as soon as the first solution appears in the GPS Processing List.

Overwrite Duplicate Baseline Solutions

This option controls how baselines are saved after reprocessing. By default the check box is selected, which means existing solutions are overwritten. If the check box is cleared, the new solution is added to the project and the old solution is retained. When this occurs, the new solution becomes the active solution and the previous solution becomes inactive. The Properties window can be used to change a previous solution back to be the active solution.

The Overwrite Duplicate Baseline Solutions check box applies only to baselines that are processed more than one time. It does not affect baselines between the same two points that are computed from GPS data collected at a different time or on a different day. Trimble recommends that you always overwrite duplicate baseline solutions


    GPS Processing List

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Dialog	See also
The GPS Processing List provides a one-line baseline solution summary in tabular format. A line is added to the list as each baseline is completed. The order in which the baseline summaries are displayed can be controlled by clicking on any of the column headings. Clicking on the column heading sorts by the values in that column. Sorting is useful to identify quickly all baselines with a low ratio, a high RMS or a high reference variance.

The GPS Processing List contains the following columns:

Use

The Use check box is selected when a baseline solution has been processed and, based on the acceptance criteria, the results are either Pass or Flag. If, based on the acceptance criteria for Ratio, Reference Variance and RMS, the results are Fail, this box is clear. Only baseline solutions for which the Use check box is selected are saved to the project when the Save button is used.

Baseline ID

The observation identifier used for this baseline in the project.

From Station

The point from which the baseline originates.

To Station

The point at which the baseline terminates. The coordinates of this point are derived by adding the baseline components to the coordinates of the from station.

Baseline Length

The slope distance of the baseline.

Solution Type

The final baseline solution type as determined by the processor. In most cases the Solution Type will be either L1 Fixed, L1 Float, Iono Free Fixed, or Iono Free Float.

Ratio

Ratio is used to evaluate the relationship between the variance of the best to the second best baseline solution (fixed solutions only).

Ref Variance

Reference Variance is a unitless number relating the actual error to the expected error of the baseline solution

NOTE: Always evaluate Ratio and Reference Variance together. Baselines with a low ratio and high reference variance should receive further attention and analysis.

RMS

RMS is the root mean square of the error of the solution of observations

NOTE: The solution summary gives a brief outline of GPS processing results. To perform a detailed analysis of individual baseline solutions, examine the GPS Baseline Processing report. You can access this report immediately after individual solutions are processed by selecting a solution from this list and clicking Report. You do not have to wait until all solutions are processed before viewing the report for individual baselines. The processor will continue processing baselines while you examine the reports for each solution.

After the GPS Processing dialog closes, you can view the report by selecting the baseline from the Graphics window and selecting Report / GPS Baseline Processing Report. The information included in the report also can be customized from the GPS Baseline Processing Report Setup dialog.


    Overwrite Duplicate Baseline Solution

More Information

 See Also

This option controls how baselines are saved after reprocessing. By default the check box is selected, which means existing solutions are overwritten. If the check box is cleared, the new solution is added to the project and the old solution is retained. When this occurs, the new solution becomes the active solution and the previous solution becomes inactive. The Properties window can be used to change a previous solution back to be the active solution.

The Overwrite Duplicate Baseline Solutions check box applies only to baselines that are processed more than one time. It does not affect baselines between the same two points that are computed from GPS data collected at a different time or on a different day. Trimble recommends that you always overwrite duplicate baseline solutions

Additional Reading

There are many considerations for processing GPS data. For more information about GPS baseline processing, see these topics:

  Determining Potential Baselines

  Selecting Baselines to Process

  Selecting a GPS Processing Style

  Starting the Baseline Processor

  Viewing the Processing Results

  Saving the Processing Results

  Reprocessing Baselines


Contents

The following Help Topics are available:

  GPS Baseline Processing Overview

  Processing GPS Baselines

  Baseline Data Sources

  GPS Processing Commands

  GPS Processing Styles

  GPS Processing Data Analysis

  GPS Baseline Processing Report

  Timeline

To learn how to use Help, press the F1 key.

If you have a problem and cannot find the information you need in this Help system, contact your local dealer or see the Technical Support.

© 1999−2002, Trimble Navigation Limited. All rights reserved.


GPS Baseline Processing Report - Overview
    GPS Baseline Processing Report − Overview

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How to ...	See also
Overview

Use the GPS Baseline Processing report to view detailed information about baseline solutions.

To access it:

1.	Process baselines. The GPS Processing dialog appears.

2.	Select a baseline solution from the GPS Processing list. The solution is highlighted.

3.	Click Report. The GPS Baseline Processing report for the baseline solution appears.

The GPS Baseline Processing report can contain the following sections:

  Processing Summary

  Baseline Components

  Occupations

  Tracking Summaries

  Residuals

  Processing Style

The sections included in the report are determined by the current settings in the GPS Baseline Processing Report Setup dialog and the type of data processed for each baselines.


Edit Advanced Style dialog - Overview
    Edit Advanced Style dialog − Overview

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Overview

GPS Processing Styles let you customize your processing for specific requirements, such as processing with precise ephemeris or a specific elevation mask. The settings can be saved as a named style and recalled at a later time simply by specifying the name of the style. This allows a processing style library to be developed to handle common processing scenarios.

The most common controls are easily accessible from the main GPS Processing Styles dialog. Additional advanced controls are also available for viewing and editing. These advanced processing controls are organized in one dialog and separated by tabs.

These tabs are available:

  Static

  Kinematic

  Global

  Quality

  Tropo

  Iono

  Events

  OTF Search


Sources of GPS Data - Overview
    Sources of GPS Data − Overview

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Overview

The baseline processor uses measurements made by GPS receivers to compute baselines. These measurements can be stored in, or referenced by:

  Trimble Data Collectors (*.dc)

  Trimble Receivers (*.dat)

  Other Manufacturer's Receivers (RINEX)

In addition to GPS measurements, these sources also provide information that is used to determine how the GPS measurements should be processed, such as when a receiver is stationary at a point, or when it is roving. This allows the baseline processor to categorize the GPS measurements as follows:

  Static/FastStatic GPS Data

  Kinematic Data

  Roving and Continuous Kinematic Data


GPS Processing Styles - Overview
    GPS Processing Styles − Overview

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Overview

GPS processing styles allow you to customize your processing for specific requirements, such as processing with precise ephemeris or a specific elevation mask. The settings can be saved as a named style and recalled at a later time simply by specifying the name of the style. This allows a processing style library to be developed to handle common processing scenarios. GPS processing styles are system wide. New styles, or changes made to an existing style, are available for use in all projects on a single PC.

The GPS Processing Styles dialog is the control center for working with styles. The currently selected style is called the Active Style. The Active Style is used to provide the processing controls to the baseline processor for subsequent processing sessions within that project. Different projects can have different Active Styles, and the Active Style can be changed between baseline processing sessions. The GPS Processing Styles dialog also provides for the ability to edit, copy, create, rename, and delete styles.

The Trimble Geomatics Office software comes with the Trimble Default GPS processing style. For most survey applications it is not necessary to modify this style. If you do modify the controls, make sure that you understand the possible effects of these changes before saving the modifications.

For more information, see Editing Styles.


GPS Baseline Processing - Overview
    GPS Baseline Processing − Overview

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Overview

The Trimble Geomatics Office software provides the ability to generate postprocessed GPS baseline solutions when the Baseline Processor Module is installed. The Baseline Processor Module includes WAVE™, the Weighted Ambiguity Vector Estimator. This program computes baseline solutions from GPS field observations made using static, FastStatic, or kinematic data collection procedures. The baseline processor uses both carrier phase and code observations to produce three-dimensional GPS baselines between survey points.

Postprocessing in the Trimble Geomatics Office software is straightforward. The baseline processor comes configured with system defaults that meet the requirements of most survey projects. Postprocessing controls also can be modified and saved in named GPS processing styles, as required, for advanced processing and reprocessing scenarios.

Separate processing sessions are not required for GPS data collected using different survey techniques. The baseline processor examines the data to be processed and then makes decisions automatically about processing strategies. Static, FastStatic and kinematic surveys can all be processed at the same time, with little, if any, advance setup required.


    Determining Potential Baselines

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A potential baseline appears in the Graphics window once you import GPS measurements collected by two receivers that also overlap in time. The amount of overlap in time must meet the minimum required for processing. Potential baselines can be, but have not yet been, processed by the baseline processor.

Potential baselines are determined automatically by the Trimble Geomatics Office software. Whenever new GPS measurements are imported into a project, the software searches for other overlapping data sets that may be processed. A potential baseline is added to the project whenever there is an overlap in time between two data sets that meet or exceed the value specified for minimum baseline observation time of the active GPS processing style, or whenever an occupation identifier is encountered in kinematic data sets.

NOTE: If you have downloaded hour-long data segments from a GPS base station before importing the data into the Trimble Geomatics Office software, combine it into one file, using the Rinmerge utility.


    Selecting Baselines to Process

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The default is to process all potential baselines in a project when Survey / Process GPS Baselines is selected. No additional steps or selections are required to process all the potential GPS baselines as they are added to the project.

Alternatively one or more specific baselines can be identified for processing, or reprocessing, by selecting only those baselines before Survey / Process GPS Baselines is selected. When one or more baselines is selected, only the selection set is considered.

Use any of the standard methods to make the selections:

  click one or more baselines in the Graphics window

  select by query

  previous selection set

NOTE: If the baseline processor displays a message indicating that no baselines have been selected without processing all the potential baselines in a project, you may have specified a selection set that does not include GPS baselines or kinematic bases. If this occurs, click in a blank area of the map in the Graphics window and then start the baseline processor again. The View Filters options also may be useful in helping to identify a subset of vectors for processing or reprocessing.

If the project contains continuous kinematic data, the default is to process all unprocessed kinematic bases. To process continuous kinematic data from a specific base, select the point at which the base was located and then initiate processing.

Baselines are processed sequentially. The direction of baseline, which station is used as the base and which is used as the rover, is determined automatically by the processor. The direction is optimized for the transfer of precise coordinates. This transfer of precise control coordinates from one point to another is referred to as coordinate seeding. The baseline processor automatically chooses the highest quality points in the processing session to use as the coordinate seed, and baselines are computed out from those points.

In most cases the processor will select the appropriate direction for processing, particularly if care has been used in setting up control and field observation sessions. In some instances, however, you may need to switch the direction of baseline by swapping the base and rover. To change the direction of the baseline flowout after processing, select the baseline on the map in the graphics window, and then select Edit / Reverse Observation Flowout.

The direction of the baseline flowout also can be used to enforce processing in a particular direction. An arrow on the baseline shows the direction of flowout. Reverse the flowout, if necessary, to enforce processing in the desired direction.

NOTE: If you have downloaded hour-long data segments from a GPS base station, before importing the data into the Trimble Geomatics Office software combine it into one file, using the Rinmerge utility.


    Selecting the GPS Processing Style

More Information

How to ...	Dialog
GPS processing styles allow you to customize your processing for specific requirements, such as processing with precise ephemeris or a specific elevation mask. The settings can be saved as a named style and recalled at a later time simply by specifying the name of the style. This allows a processing style library to be developed to handle common processing scenarios. GPS processing styles are system wide. New styles, or changes made to an existing style, are available for use in all projects on a single PC.

The GPS Processing Styles dialog is the control center for working with styles. The currently selected style is called the active style. The active style is used to provide the processing controls to the baseline processor for subsequent processing sessions within that project. Selecting a style from the styles list makes that style the current active style for that project.

Different projects can have different active styles, and the active style can be changed between baseline processing sessions. The GPS Processing Styles dialog also provides for the ability to edit, copy, create, rename, and delete styles.

Trimble Geomatics Office software comes with the Trimble default GPS processing style. For most survey applications it is not necessary to modify this style. If you do modify the controls, make sure that you understand the possible effects of these changes before saving the modifications.


    When to Use the GPS Baseline Processor

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 See also

Most surveyors process survey data immediately after the field sessions to determine if any of the baselines require reobservation.

Before using the baseline processor, do the following:

  Create the project.

  Plan the field observations (recommended).

  Collect the data in the field.

  Download the data from receivers, survey devices, or your computer into the Trimble Geomatics Office software project.

Usually baseline processing is not the final step in a GPS survey project. Your processing results will reflect the overall quality of your GPS measurements, but good surveying practice should include a network adjustment of all your observations. Network adjustment will help determine the consistency of your observed baselines within the network and will generate final coordinates. See the Trimble Geomatics Office software Network Adjustment Help.


GPS Baseline Processing Commands - Overview
    GPS Baseline Processing Commands − Overview

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Overview

GPS baseline processing commands are available on the Survey and Report menus.

These Survey menu commands are available:

  GPS Processing Styles

  GPS Processing

The Reports menu has the following commands available:

  GPS Baseline Processing Report

  GPS Baseline Processing Report Setup

The View menu has the following commands available:

  Timeline

  Planning Plots (Toolbars)

  Timeline (Toolbars)

These Survey view commands are also useful before and after processing GPS baselines:

  GPS Loop Closures Report

  Recompute

  Recompute Report

  Timeline


Processing GPS Baselines - Overview
    Processing GPS Baselines − Overview

The baseline processor computes baselines from GPS field observations made using static, FastStatic, or kinematic data collection procedures. The baseline processor uses both carrier phase and code observations to produce three dimensional GPS baselines between survey points.

There are many considerations for processing GPS data. For more information about GPS baseline processing, see these topics:

  Determining Potential Baselines

  Selecting Baselines to Process

  Selecting a GPS Processing Style

  Starting the Baseline Processor

  Viewing the Processing Results

  Saving the Processing Results

  Reprocessing Baselines


    Starting the GPS Baseline Processor

More Information

How to ...	Dialog	See also
The baseline processor is available only if you are working in the Survey view and you have imported two or more files with GPS measurements into your project.

Processing all Potential Baselines

To process all potential baselines:

1.	Open a project containing one or more potential baselines.

2.	To start the processor, do one of the following:

  From the Survey menu, select Process GPS Baselines.

  From the Trimble Survey Group in the project bar, select Process GPS Baselines.

  From the Process Group in the project bar, select Process GPS Baselines.

  Press F9.

The GPS Processing dialog appears and the baseline processor starts processing all potential baselines.

Processing one or more Selected Baselines

To process or reprocess one or more selected baselines:

1.	Open a project containing one or more potential or saved baselines.

2.	To create a selection set of the baselines to be processed using any of the standard selection methods, do one of the following:

  Click on one or more baselines in the Graphics window

  Select by query

  Previous selection set

3.	Selected baselines appear in the graphics window as a thicker line.

4.	To start the processor, do one of the following:

  From the Survey menu, select Process GPS Baselines.

  From the Trimble Survey Group in the project bar, select Process GPS Baselines.

  From the process group in the project bar, select Process GPS Baselines.

  Press F9.

The GPS Processing dialog appears and the baseline processor starts processing all selected baselines.

Processing Continuous Kinematic Baselines

To process continuous kinematic baselines:

1.	Open a project containing continuous kinematic data.

2.	Select the point at which the base receiver was located during the survey.

3.	To start the processor, do one of the following:

  From the Survey menu, select Process GPS Baselines.

  From the Trimble Survey Group in the project bar, select Process GPS Baselines.

  From the Process Group in the project bar, select Process GPS Baselines.

  Press F9.

The GPS Processing dialog appears and the baseline processor starts processing the kinematic baselines.

Processing a Specific set of Kinematic Baselines

To process a specific set of continuous kinematic baselines:

1.	Open a project containing continuous kinematic data.

2.	To view Timeline, do one of the following:

  Select View / Timeline.

  Press Alt+VI.

The Timeline view area appears.

3.	Select the base receiver occupation for the survey.

4.	To start the processor, do one of the following:

  From the Survey menu, select Process GPS Baselines.

  From the Trimble Survey Group in the project bar, select Process GPS Baselines.

  From the Process Group in the project bar, select Process GPS Baselines.

  Press F9.

The GPS Processing dialog appears and the baseline processor starts processing the kinematic baselines.

Monitoring the GPS Processing Dialog’s Status Bar

The status bar, located at the bottom of the GPS Processing dialog, shows the progress of each file as it is loaded for processing. The From and To station names appear for each baseline during processing, and a one line summary with processing results appears in the GPS Processing list upon completion of each baseline. The baseline processor then proceeds to process the next baseline. The status bar is updated after each baseline to indicate current status. It also shows a count of the baselines accepted (Acc) and rejected (Rej), based on the default acceptance criteria as set in the active GPS processing style.

For more information about a baseline processing session, see Baseline Processing Log.


    Viewing the Processing Results

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How to ...	Dialog	See also
The GPS Processing dialog automatically appears when you process your baselines. The status bar, located at the bottom of this dialog, shows the progress of each file as it is loaded. The From and To station names appear for each baseline during processing, and a one line summary with processing results appears in the GPS Processing list upon completion of each baseline. The baseline processor then proceeds to process the next baseline. The status bar is updated after each baseline to indicate current status. It also shows a count of the baselines accepted (Acc) and rejected (Rej), based on the default acceptance criteria as set in the active GPS processing style.

For more information, see these topics:

  Using the GPS Processing Dialog

  Using the GPS Baseline Processing Report


    Using the GPS Processing dialog

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How to ...	Dialog	See also
The GPS Processing dialog shows:

  processing status

  number of baselines processed

  number of baselines that have been accepted and rejected

  one-line summary of processing results in tabular format

  pending status of processed baselines

The GPS Processing dialog also provides the ability to:

  save baseline processing results to the project

  generate a GPS Baseline Processing Report

  control how baselines are saved after reprocessing

These controls are available:

GPS Processing List

Watch this list to monitor the results of the GPS processing session. For more information about the list columns, see GPS Processing List.

GPS Processing Status Indicators

A GPS Processing indicator is displayed on the status bar. Clicking on this indicator will recenter the GPS Processing Dialog.

The progress indicator on the left side of the status bar monitors the progress of each baseline processing solution.

The second indicator displays messages generated by the GPS processor. Individual baseline starting points and ending points are displayed as the session continues.

The number of files to process and the remaining number of baselines to process appear in the third status bar indicator from the right. This indicator reads Pending after all baselines are processed and before Save is clicked to store the solutions in the project.

The status indicator on the far right summarizes the number of accepted and rejected baseline solutions.

Stop / Save

Before processing is complete, you can click Stop to halt further processing without canceling the baseline processing session. After processing is complete, the Stop button becomes the Save button. Select Save to save the solutions that are selected in the GPS Processing list to the project. Selected baseline solutions are indicated by a check mark in the Use box. A save operation is also affected by the Overwrite Duplicate Baseline Solutions check box, as described below.

Cancel

Select this button at any time after GPS processing begins to abort the GPS processing session.

  If GPS processing is already completed when this button is clicked, a verification message appears. If you click Yes, the processed solutions are discarded and the dialog closes. If you click No, you are returned to the GPS Processing dialog.

  If GPS processing is under way when this button is clicked, processing stops after the current baseline solution is completed and a verification message appears. If you click Yes, the processed solutions are discarded and the dialog closes. If you click No, you are returned to the GPS Processing dialog.

Report

Select this button to view the GPS Baseline Processing Report for the selected baseline solution. A baseline solution must be selected from the GPS Processing list before this button becomes available.

Overwrite Duplicate Baseline Solutions

This option controls how baselines are saved after reprocessing. By default, the check box is selected, which means existing solutions are overwritten. If the check box is cleared, the new solution is added to the project and the old solution is retained. When this occurs the new solution becomes the active solution and the previous solution becomes inactive. The Properties window can be used to change a previous solution back to be the active solution.

The Overwrite Duplicate Baseline Solutions option applies only to baselines that are processed more than one time. It does not affect baselines between the same two points that are computed from GPS data collected at a different time or on a different day. Trimble recommends that you always overwrite duplicate baseline solutions


    Using the GPS Baseline Processing Report

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The GPS Baseline Processing Report provides detailed information about a baseline solution.

To generate a GPS Processing Report, do one of the following:

  Double-click a baseline in the GPS Processing dialog.

  Select a baseline in the GPS Processing dialog, and click Report.

  Select a baseline in the Graphic window and select Reports / GPS Baseline Processing Report

The GPS Baseline Processing report can be used to:

  Examine the details of the baseline solution that are not available in the one-line summary, such as errors in NEU (North-East-Up), or the number of measurements used and the number rejected.

  Verify the station information in the solution against your field notes. Pay particular attention to:

  Station names

  Antenna heights, types and measurement methods

  Start and stop times

  Check the Satellite Phase Tracking Summary at each station for breaks or gaps in the L1 or L2 signal.

  Check the combined Satellite Phase Tracking Summary. The gray shading indicates the measurements actually used in the baseline solution.

  Check the Residual plots for each satellite. These show the RMS for each satellite used to determine the baseline solution.


    Saving Processing Results

More Information

Dialog	See also
Click the Save button in the GPS Processing dialog to save the baseline solutions that are selected in the GPS Processing list into the project. Selected baseline solutions are indicated by a check mark in the Use box.

If the processing session includes reprocessed baselines, the save will be affected by the Overwrite Duplicate Baseline Solutions check box. This option controls how baselines are saved after reprocessing. By default this check box is selected, which means existing solutions are overwritten. If the check box is cleared, the new solution is added to the project and the old solution is retained. When this occurs, the new solution becomes the active solution and the previous solution becomes inactive. The Properties window can be used to change a previous solution back to be the active solution.

The Overwrite Duplicate Baseline Solutions check box applies only to baselines that are processed more than one time. It does not affect baselines between the same two points that are computed from GPS data collected at a different time or on a different day. Trimble recommends that you always overwrite duplicate baseline solutions


     L1 Fixed

 Overview and more information

For short baselines of a few kilometers in length, an L1-only final pass is generated instead of Iono Free Fixed when dual-frequency data is used for processing. This final L1-only solution, however, is generated using the dual-frequency data to help derive the L1 ambiguities. For baselines in the range of approximately 5 kilometers or less, the L1 Fixed solution is generally preferable because there is less noise in the solution.

The value used as the cutoff for L1-only solutions can be set using the GPS processing style.


    Iono Free Fixed

 Overview and more information

The Iono Free Fixed solution is the optimum solution under the widest range of conditions. These solutions contain no ionospheric biases, and fixed ambiguities give the best overall results.

An Iono Free Fixed solution on short baselines, however, can be a weak solution. Avoid using such solutions for short baselines. The Trimble Geomatics Office software automatically identifies short baselines and selects the appropriate final solution type.

See L1 Fixed for more information.


    L1 Float

 Overview and more information

When processing single-frequency data, the baseline processor generates an L1 Fixed final pass solution if L1 ambiguities can be successfully determined. If the L1 search is not successful, however, an L1 Float solution is generated. An L1 Float solution for a short baseline may arise from too brief an occupation or unusually noisy observations. For baselines of 10 to 15 kilometers and more, it can become increasingly difficult to obtain reliable L1 Fixed solutions due to the sensitivity of single-frequency observations to ionospheric delays.

L1 Float solutions generally are weaker than fixed-integer solutions. For standard survey applications, Trimble does not recommend that you use L1 Float solutions. You should either reprocess your data or reobserve these baselines.

The decision to produce a fixed-integer solution is controlled by the ratio cutoff specified internally by the baseline processor. The cutoff is set internally by the processor to 1.5. When the computed ratio is less than this internal ratio cutoff value, float solutions are produced.


    Iono Free Float

 Overview and more information

An Iono Free Float solution on baselines longer than 30 kilometers may be a very good solution, but make sure to verify it. On very long baselines, an Iono Free Float solution may be the best you can achieve. Longer occupation times result in better Iono Free Float solutions, since the unbiased Iono Free observable allows the solution to converge toward the correct geometric result. In fact, Iono Free Float solutions on very long lines, occupied for several hours, can give excellent results.

For very long baselines (several hundred to several thousand kilometers), select a float solution type to generate an Iono Free Float solution using the dual-frequency data. As mentioned previously, long occupation times on very long lines can give excellent Iono Free Float solutions.

The value used as the cutoff for float solutions for very long baselines can be set using the GPS processing style. Separate criteria can be set for the use of broadcast and precise ephemeris.


GPS Processing Data Analysis - Overview
    GPS Processing Data Analysis − Overview

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Overview

Evaluation of the quality of the measurements is an important task. Because the observation technique itself (the collection of carrier-phase data from satellites) is not as physically obvious as the measurement of distances and angles by more traditional techniques, you must rely on postprocessing tools to evaluate the results. There are a number of simple guidelines that, if followed carefully, will lead to better GPS surveys.

If the baseline processing results are not as good as you expected, there are several options for improving your results before you have to go back out and reobserve those problematic baselines. The information in the GPS Baseline Processing report can help identify satellite signal interference and isolate the observation time at which signal problems occurred. This report may be useful if you decide to reprocess the data using a different GPS processing style.

Potential Problems

Poor GPS processing results can occur for a variety of reasons, including:

  field blunders, such as:

  incorrect antenna height measurements

  incorrect naming of stations

  tripod centering errors

  inconsistencies in receiver settings, such as:

  sync rates

  SVs enabled or disabled

  data formats

  collecting data under marginal conditions, such as:

  observing too few satellites

  high PDOP

  too many satellites at low elevation angles

  bad multipath conditions

  many cycle slips

  insufficient observation time

The first category of potential errors are operator mistakes, or blunders. You can reduce blunders by adopting good field procedures. Measuring and recording antenna heights in both feet and meters, and then recording them at the start and end of occupations, helps to eliminate measurement errors. Using a fixed-height tripod helps to reduce error in reading a tape and avoids the subsequent transposition of numbers. Making clear, accurate field notes for station names, locations, observation times and antenna heights can prove invaluable if questions arise when processing data.

The second category of potential errors is more difficult to reconcile. Ideally, a GPS survey would always have six satellites, good PDOP, no trees and unobstructed visibility. It is unreasonable to expect, however, that this will be the case. Therefore, it is necessary to formulate and follow field-proven methods that take these real-world conditions into account.

Improving Quality

There are a number of steps you can take to maximize the accuracy of your GPS survey results. Consider these guidelines:

  Choose the best conditions possible, given the constraints of the job. Use QuickPlan to choose periods of good PDOP and sufficient number of satellites. To maximize the quality of your vertical results, examine VDOP as well.

  Visit your stations ahead of time to look for obstructions and possible sources of multipath; relocate stations (if possible) that are heavily obstructed. This is particularly important for base stations in kinematic surveys.

  Verify that the settings for all receivers used during the same survey session are compatible.

  Observe for an adequate period of time, given the conditions. If you are unsure of the guidelines, extend your observation times a little until you have more experience. In the case of kinematic surveying, pay particular attention to initializations, adding some additional time to static initializations or periods of on-the-fly initialization. As you decrease observation times, you increase the likelihood that you will have to reobserve baselines.

  Use good surveying practices and make redundant measurements. Observe critical baselines twice, in independent sessions. Design your network so that all stations have at least three independent baselines attached to them. That way, if it is impossible to solve one of the baseline observations, you can still compute the station coordinates without returning to the field.

  Structure your network design such that small closed figures are created from baselines observed in two or more sessions. This ensures that loop closures are meaningful. If all the baselines in a loop are from the same session, station setup errors that are common to all the baselines in that session cannot be detected.

  Learn how to evaluate the output from the baseline processor. A number of simple guidelines will help you to detect and evaluate marginal results. (A discussion of evaluation of processing results follows.)

  Use the network adjustment module, if installed. You do not really know whether your work is done until all of the baselines in a job are brought together and adjusted simultaneously. A rigorous network adjustment is your most powerful tool for detecting blunders and systematic errors in your network.

The steps listed above, together with the tools provided in the Trimble Geomatics Office software, such as Recompute, Loop Closures and the optional Network Adjustment module, all help to ensure that your network meets the specifications required for your project.

These topics give additional guidelines for processing, examining, and improving GPS data quality:

  GPS Baseline Processing Report

  Reprocess Problematic Baselines

  Examine Data with Timeline

  Correct Cycle Slips

  Correct Invalid Range Data

  Disable GPS Observations

  Disable Selected Satellites


    Multipath

Overview and More Information
Multipath increases the GPS satellite signal travel time due to the reflection of the signals off of a variety of surfaces. Common sources of multipath include:

  bodies of water

  buildings

  vehicles

  chain link fences

Urban areas in particular can cause considerable multipath problems.

The Residual Plot displays multipath as an underlying sine wave within the plot. The sine wave size depends upon the satellite signal strength and the distance between the multipath source and the antenna phase center of the receiver. Multipath is difficult to identify in less than fifteen minutes of data. If you suspect multipath in an area, plan longer occupation times so that the baseline processor has enough data to average out the effects. Using an antenna with a ground plane, or a choke ring antenna will also help reduce these affects.


     Reprocessing Baselines

More Information

How to ...	See also
Perform the following steps to reprocess baselines:

1.	Select the active GPS processing style to be used for reprocessing.

2.	To create a selection set of the baselines to be reprocessed using any of the standard selection methods, do one of the following:

  Click on one or more baselines in the Graphics window

  Select by query

  Previous selection set

3.	To start the processor, do one of the following:

  From the Survey menu, select Process GPS Baselines.

  From the Trimble Survey Group in the project bar, select Process GPS Baselines.

  From the Process Group in the project bar, select Process GPS Baselines.

The GPS Processing dialog appears and the baseline processor starts reprocessing all selected baselines. Use the GPS Processing List to evaluate the results of the processing and decide whether you want to keep or discard the new results. Check the status of the Overwrite Duplicate Baseline Solutions check box before saving the new results to the project.

The Overwrite Duplicate Baseline Solutions check box controls how baselines are saved after reprocessing. By default the check box is selected, which means existing solutions are overwritten. If the check box is cleared, the new solution is added to the project and the old solution is retained. When this occurs, the new solution becomes the active solution and the previous solution becomes inactive. The Properties window can be used to change a previous solution back to be the active solution.

The Overwrite Duplicate Baseline Solutions check box applies only to baselines that are processed more than one time. It does not affect baselines between the same two points that are computed from GPS data collected at a different time or on a different day. It is recommended that you always overwrite duplicate baseline solutions.


    Cycle Slips

Overview and More Information
A cycle slip is a break in continuous satellite tracking. The wave fronts that the receiver counts during continuous carrier tracking are also referred to as cycles. Therefore, when the receiver loses count because of an interruption in satellite tracking, the cycle or wave counting slips. Hence, a cycle slip causes continuous carrier phase to be reset. This is not necessarily a bad situation, provided the baseline processor can re-establish the count through its computations.

There are a number of things that interrupt the satellite signal, both while stationary or moving. While stationary, slips can occur due to a weak, low-elevation satellite, or signal disruption due to obstructions such as trees. While moving, there are many things which can cause cycle slips: passing under a bridge, driving through a tunnel, driving or walking under a tree, or simply placing your hand over the GPS antenna. Be on the lookout for situations that can cause cycle slips and avoid them if you can.


GPS Baseline Processing Report - Processing Summary
    GPS Baseline Processing Report − Processing Summary

This section of the GPS Baseline Processing report lets you quickly determine which baselines are successfully processed, and which baselines need further investigation.

To access the Processing Summary, use one of the following methods:

  In the GPS Processing dialog, double-click a one-line solution summary.

  Select one or more baselines, and in the GPS Processing dialog, click Report.

  In the graphics window, select baselines and then select Reports / GPS Baseline Processing Report.

The following information is shown:

Column	What it shows
ID	The baseline identifier.
From	The name of the station that the GPS observation was made from.
To	The name of the station that the GPS observation was made to.
Baseline Length	The length of the baseline between the from and to stations.
Solution Type	The solution type. The most common reported types are L1 fixed solutions for short baselines, and iono-free fixed solutions for medium lines. If you process very long lines, iono-free float solutions may be used.
Ratio	The baseline processor compares the two solutions with the lowest variance. The ratio is the variance of the second best solution divided by the variance of the best solution.  NOTE: Only fixed solutions have ratios.
Reference Variance	The reference variance is a unitless number that indicates how well the observed data fits the baseline solution.
RMS	The RMS (Root Mean Square). RMS indicates the quality of the solution based solely on the measurement noise of the satellite ranging observations. It is independent of satellite geometry.


GPS Baseline Processing Report - Baseline Summary
GPS Baseline Processing Report − Baseline Summary

This section of the GPS Baseline Processing report shows the summary information for a specified baseline. To investigate this baseline:

1.	Select Reports / GPS Baseline Processing Report. The Baseline Processing report appears.

2.	Select the baseline from the Processing Summary.

The following information is shown:

Field	What it shows
Processed	The day, date, and time when the solution was processed.
Solution Type	The most common types reported are L1 fixed solutions for short baselines, and iono-free fixed solutions for medium lines. If you process very long lines, iono-free float solutions may be used.
Solution Acceptability	Whether the solution passed the acceptance criteria set in the GPS Processing Styles dialog.
Ephemeris Used	Whether broadcast or precise ephemeris was used when determining the baseline solution.
Met Data	The meterological model used.
Baseline Slope Distance	The slope distance of the baseline.
Elevation Mask	The elevation mask set during the processing. This value is set in the GPS Processing Styles dialog.
Variance Ratio	The baseline processor compares the two solutions with the lowest variance. The ratio is the variance of the second best solution divided by the variance of the best solution.  NOTE: Only fixed solutions have ratios.
Reference variance	The reference variance is a unitless number that indicates how well the observed data fits the baseline solution.
RMS	The RMS (Root Mean Square). RMS indicates the quality of the solution based solely on the measurement noise of the satellite ranging observations. It is independent of satellite geometry.
Horizontal Precision	The horizontal precision of the observation.
Vertical Precision	The vertical precision of the observation.
Start time (GPS Time)	The start time of the GPS observation.
Stop time (GPS Time)	The stop time of the GPS observation.
Occupation time	The length of the occupation; that is, the difference between the start time and the stop time of the GPS observation.


GPS Baseline Processing Report – Baseline Components
GPS Baseline Processing Report − Baseline Components

This section of the GPS Baseline Processing report shows the coordinates for two points that are occupied during the observation. The baseline components between the two points, the standard errors, and the a posteriori covariance matrix are also shown.

To access the Baseline Components section:

1.	Select Reports \ GPS Baseline Processing Report. The GPS Baseline Processing report appears.

2.	Select the baseline from the Processing Summary. The Baseline Summary appears.

3.	From the Contents, select Baseline Components.

The coordinates for each point are displayed; that is grid, local, and WGS-84 coordinates.

The following fields are shown in the Baseline Components table:

  Delta northing, easting, and elevation

  Normal Section Forward Azimuth

  Ellipsoid distance

  Delta height

  Delta X, Y and Z

The following fields are shown in the Standard Errors table:

  σ Northing, σ Easting, σ Elevation

  σ Normal Section Azimuth

  σ Ellipsoid Distance

  σ Delta Height

  σX, σY, σZ

The covariance information is shown in the A posteriori Covariance Matrix table.


GPS Baseline Processing Report - Occupations
GPS Baseline Processing Report − Occupations

This section of the Baseline Processing report shows details about the GPS receiver and the antenna used to observe the points in the survey.

To access the Occupations section:

1.	Select Reports \ GPS Baseline Processing Report. The GPS Baseline Processing report appears.

2.	Select the baseline from the Processing Summary. The Baseline Summary appears.

3. 	From the Contents, select Occupations.

The following information is shown:

Field	What it shows
Point name	The names of the points that were occupied with the GPS receiver.
Data file	The filenames (.dat files) used to store data at the from and to points.
Receiver Type	The types of GPS receiver used in the observations.
Receiver Serial Number	The serial number of the GPS receiver.
Antenna Type	The type of GPS antenna.
Measure To	The point on the GPS antenna that was measured to when determining the height of the antenna.
Antenna Height	The height of the GPS antenna that was measured, and the height of the antenna to the Antenna Phase Centre (APC).  NOTE: The APC value is calculated according to the type of antenna.
Antenna Model	The model of GPS antenna.


GPS Processing Report – Processing Style
GPS Processing Report − Processing Style

This section of the Baseline Processing report summarises the controls used in the processing. These controls are set in the GPS Processing Styles dialog. You must ensure that the correct settings are used in your GPS baseline processing.

To access the Processing Style section:

1.	Select Reports / GPS Baseline Processing Report. The GPS Baseline Processing report appears.

2.	Select the baseline from the Processing Summary. The Baseline Summary appears.

3.	From the Contents, select Processing Style.

The following fields are shown:

Section	Fields
Processing Style − shows the name of the processing style used.	Elevation mask Ephemeris type Solution type
Static − shows the static processor controls.	Minimum baseline observation time Maximum baseline length to attempt to fix a solution—two settings are shown; one for using the broadcast ephemeris and one for using precise ephemeris.
Kinematic − shows the  kinematic processor controls.	Minimum reference observation time Minimum static initialization observation time Minimum known point initialization ratio Minimum OTF processing time
Global − shows the global setting made in the global setting tab.	Frequency type Maximum fixable cycle slip (static processing only) Maximum iterations (static processing only) Maximum integer search time (static processing only)
Quality	RMS acceptable criteria Ratio acceptance critieria Reference variance acceptance criteria Edit multiplier
Tropo	Model Minimum zenith delay interval Use observed met data
Iono	Ambiguity Resolution pass (static processing only) Final Pass
Events	Interpolation Method Number of points to fit Maximum allowed missing epochs Time offset NOTE: You can view events data in the Properties window.
OTF Search – shows the method used for On-The-Fly searches.


GPS Baseline Processing Report - Station Tracking Summaries
    GPS Baseline Processing Report − Tracking Summary

The Baseline Processing report includes satellite tracking summaries at each point, and also a combined tracking summary.

To access the Tracking Summaries section:

1.	Select Reports \ GPS Baseline Processing Report. The GPS Baseline Processing report appears.

2.	Select the baseline from the Processing Summary. The Baseline Summary appears.

3. 	From the Contents, select Tracking Summary.

Individual Point Summaries

These summaries indicate the quality of the tracking of the L1 and L2 signals received from each satellite.

The satellite tracking summaries indicate the continuity of the satellite tracking at both the base and rover stations. The summaries indicate continuous tracking throughout the observation session by using solid, continuous lines for each satellite at each station.

Use the summaries to determine the size and number of cycle slips (loss of lock) that occur. Cycle slips on a satellite are indicated by gaps and breaks in the data. After a cycle slip, tick marks indicate when the receiver picks up the satellite signal again.

Combined Summary

Because baseline processing requires the simultaneous tracking of the same satellites at each station, the GPS Baseline Processing report also includes a plot of the combined tracking.

The segments used in processing are shown as gray boxes surrounding the signal. A gap in the processed phase segments shows that the baseline processor did not use those segments of data to process the baseline.


GPS Baseline Processing Report - Continuous Kinematic Quality
    GPS Baseline Processing Report − Continuous Kinematic Quality

More Information

How to ...	Report	See also

This section is included only after processing continuous kinematic data. The Continuous Kinematic Quality section contains two plots.

To access the continuous kinematic quality information:

1.	Select Reports \ GPS Baseline Processing Report. The GPS Baseline Processing report appears.

2.	Select the baseline from the Processing Summary. The Baseline Summary appears.

3. 	From the Contents, select Continuous Kinematic Quality.

The first is a plot of the RMS for each continuous kinematic baseline plotted against time. It can be used to identify time when poor results may be present. A constant increase in RMS over time also can indicate that problems may have occurred during processing.

The second is a plot of RDOP and number of SVs against time. This plot is used to identify times when there may have been poor satellite geometry, and hence poor processing results.


GPS Baseline Processing Report - Residuals
    GPS Baseline Processing Report − Residuals

The residual plots are a graphical representation of the observation residuals for each satellite used in the baseline solution.

The residual plots indicate the quality of data received from each satellite. You can use this plot to get a feel for the amount of noise in the solution. This plot shows the residuals for each satellite for each measurement cycle. Noisy satellites may affect data coming from other satellites. The lines on the graph should be centered around zero. The amount of noise in the solution is indicated by how far the plot varies from zero.

Residuals are not shown for the satellite chosen by the processor as the base for double differencing. For long occupations, more than one satellite may be chosen by the processor for this purpose. Gaps in the residual plot typically mean that, for that period of time, the satellite was used as the base for double differencing.


    L1 Only versus Iono Free Solutions

The Iono Free Fixed solution is the optimum solution under the widest range of conditions. These solutions contain no ionospheric biases, and fixed ambiguities give the best overall results.

An Iono Free Fixed solution on short baselines, however, can be a weak solution. Avoid using such solutions for short baselines. The Trimble Geomatics Office software automatically identifies short baselines and selects the appropriate final solution type.

An Iono Free Float solution on baselines longer than 30 kilometers may be a very good solution, but make sure to verify it. On very long baselines an Iono Free Float solution may be the best you can achieve. Longer occupation times result in better Iono Free Float solutions since the unbiased Iono Free observable allows the solution to converge toward the correct geometric result. In fact, Iono Free Float solutions on very long lines, occupied for several hours, can give excellent results.

For very short baselines (less than 5 kilometers), an L1-only final pass (derived from the dual-frequency ambiguities) typically is the final solution; for very long baselines (more than 200 kilometers using broadcast ephemeris, 2000 kilometers using precise ephemeris) an Iono Free Float final pass may be the final solution, as follows:

Very Short Baselines

For short baselines of a few kilometers in length, an L1-only final pass is generated instead of Iono Free Fixed. This final L1-only solution, however, is generated using the dual-frequency data to help derive the L1 ambiguities. For baselines in the range of approximately 5 kilometers or less, the L1 Fixed solution is generally preferable because there is less noise in the solution.

The value used as the cutoff for L1-only solutions can be set using GPS processing styles.

Very Long Baselines

For very long baselines (several hundred to several thousand kilometers), select a Float solution type to generate an Iono Free Float solution using the dual-frequency data. As mentioned previously, long occupation times on very long lines can give excellent Iono Free Float solutions.

The value used as the cutoff for float solutions for very long baselines can be set using GPS processing styles. Separate criteria can be set for the use of broadcast and precise ephemeris.


    Float Solutions

More Information

How to ...	Report	See also

When processing single-frequency data, the baseline processor generates an L1 Fixed final pass solution if L1 ambiguities can be successfully determined. If the L1 search is not successful, however, an L1 Float solution is generated. An L1 Float solution for a very short line may arise from too brief an occupation or unusually noisy observations. For baselines of 10 to 15 kilometers and more, it can become increasingly difficult to obtain reliable L1 Fixed solutions due to the sensitivity of single-frequency observations to ionospheric delays.

L1 Float solutions generally are weaker than fixed-integer solutions. For standard survey applications it is recommended that you avoid using L1 Float solutions. You should either reprocess your data or reobserve these baselines in the field.

The decision to produce a fixed-integer solution is controlled by the ratio cutoff specified internally by the baseline processor. The cutoff is set to 1.5. When the computed ratio is less than this ratio cutoff value, float solutions are produced.


    GPS Baseline Processing Report Setup dialog

More Information

How to ...	See also

Use this dialog to select the sections appearing in the GPS Baseline Processing report.

To access it, do one of the following:

  Select Reports / Setup / GPS Baseline Processing Report.

  Press Alt+RSO.

The GPS Baseline Processing Report Setup dialog appears.

Select or clear the check boxes provided to add or remove the following report sections:

  Baseline Summary

  Baseline Components

  Occupations

  Processing Style

  Combined Tracking Summary

  Continuous Kinematic Quality

  Residuals


    Trimble Data Collectors (*.dc)

These files typically contain information obtained during real-time kinematic (RTK) or conventional surveys. The Trimble data collector files can be used to reference GPS measurements used for postprocessing when radio communication is not possible. In this case the point information is stored in the data collector file and raw GPS measurements are stored in a related .dat file for later processing. The GPS measurements referenced by the data collector file are used by the baseline processor in the Trimble Geomatics Office software to compute baselines that could not be solved in real time.

Although the GPS measurements are stored in separate .dat files, they can be loaded automatically by the import procedure because of the references in the data collector file itself. They do not have to be loaded as independent files.

Data collector files can include measurements collected during several survey sessions, each collected using different survey methods.


    Trimble Receivers (*.dat)

These files contain the measurements obtained by a Trimble GPS receiver. These files are typically recorded to the receiver memory board, or to a memory card in a Trimble data collector. These files are downloaded from the survey device into the Trimble Geomatics Office software for processing. The measurements contained in these files are used by the processor to compute baselines using static, FastStatic and kinematic techniques.


    Other Receiver Manufacturers (RINEX)

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These files contain measurements obtained by a GPS receiver. They are similar in content to .dat files, but are stored in the Receiver INdependent EXchange format (RINEX). The RINEX format is an ASCII representation of GPS data collected by receivers. RINEX files include observation, navigation, and meteorological data.

RINEX files are typically obtained from base stations, such as from the IGS Tracking Network, the Continuously Operating Reference Stations (CORS) in the United States, or from other manufacturers’ software. The processor uses these files just as it does .dat files to obtain vector baseline solutions.


    Static/FastStatic GPS Data

More Information

 See also

The following distinctions exist between the data collected during a Static survey session and FastStatic survey session.

For Static sessions, the receiver is assumed to:

  remain stationary over a single point

  collect data for a longer period of time than for FastStatic.

For FastStatic sessions, the receiver is assumed to:

  move to several points and remain stationary while collecting data at each point, and

  not collect data while the receiver is moving from point to point, and

  collect data for a shorter period of time than for a static session

The most important distinction between Static and FastStatic is the minimum time required for the receiver to record data (the occupation time). This time depends on your application, the baseline length, and whether you are using single or dual-frequency receivers.

Static occupation times can range from 30 minutes to several hours or more in length for applications requiring the highest levels of precision and repeatability. FastStatic occupation times are around 8 minutes for surveys conducted with dual-frequency receivers, but may be longer based on local conditions.

In general, longer baselines require longer occupation times. As occupation times increase, so does the confidence in the computed result. The time required to remain on station depends on the satellite constellation. The occupation time decreases as the number of satellites in view increases. Occupation times also depend on the length of the baseline being observed. Longer baselines, in general, require longer occupation times, regardless of the satellite constellation.

Static and FastStatic survey methods offer the highest possible GPS precisions. Best results are usually achieved when you plan in advance to use Static and FastStatic data collection sessions in conjunction with one another.


    Kinematic Data

More Information

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The distinction between a Kinematic survey session and Static or FastStatic sessions is the mobile or roving action of the receiver while data is collected; receivers generally do not remain stationary while collecting Kinematic data.

Another important distinction between Kinematic and Static/FastStatic survey methods is the occupation time. In Kinematic surveying, the station occupation time is dramatically shortened (after initialization). It can vary from minutes down to seconds, depending on the application. This allows for a highly productive survey; many data points can be collected in a short period of time.

However, this increased productivity has a disadvantage: the attainable precisions are lower than with the Static/FastStatic methods and the shorter occupations are more susceptible to multipath because of the smaller amount of data. The precisions associated with Kinematic surveying limit its use to GPS applications where high precision is not a requirement.

Kinematic surveying requires an initialization step to solve for the unknown integer ambiguity in the GPS signal when lock on the satellite is acquired. This ambiguity must be solved for during processing to obtain the high precision results required for survey applications.

Once initialization occurs, you can use short occupations at survey points. The Trimble Geomatics Office software can apply the initialization to subsequent solutions. Therefore, once initialization occurs you only need an occupation time with enough data to obtain the new position.

Four types of initializations exist:

  Known Point

  Static

  Post-processed On-The-Fly (OTF)

  Reoccupation


    Static Initialization

More Information

 See also

Static initialization requires the base receiver to occupy a known reference point while the rover occupies any other point. The rover stays stationary on its point for the amount of time required for a normal FastStatic occupation. The occupation time will vary according to the number of satellites available and the type of receivers used in the survey. Consider FastStatic occupation time recommendations and your own experience, based on satellite availability and local conditions.


    Known Point Initialization

More Information

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Known point initialization is the fastest and most reliable of all the initialization types. Both the base and roving receivers are set up on known or previously surveyed points, and the rover stays stationary for at least 30 seconds on its point. The baseline processor uses the known coordinates as additional information during initialization.


    Postprocessed On-the-Fly (OTF) Initialization

More Information

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OTF initialization requires maintaining lock on five satellites. The base receiver is placed on a known point and collects GPS measurements. The rover collects measurements for this same time period, but the rover is not required to remain stationary on any point for any specified length of time. The baseline processor can use this data for initialization, even if the rover was moving during the entire time the data was collected.


    Reoccupation Initialization

More Information

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Reoccupation initialization is similar to known point initialization, only the point occupied by the rover is not known ahead of time. Instead the rover occupies a point that was previously occupied in the same kinematic field session. An assumption is made that the baseline processor will be able to solve the baseline from the base to the rover for the previous occupation of that same point. If this assumption proves true, then that previous baseline solution can be used later for initialization. The rover should remain stationary over the previously occupied point for at least 30 seconds.


    Roving and Continuous Kinematic Data

More Information

 See also

Continuous Kinematic surveying lets you perform these operations:

  Map topographic features, such as profiles, cross sections, and contours.

  Map the paths of moving vehicles, such as airplanes or boats, and also determine the coordinates for instantaneous events, such as the opening of a camera shutter. Events are generated in the receiver by sending a signal to the receiver event port, which triggers the storage of an event marker.

Continuous kinematic surveying has the same restrictions as Stop & Go Kinematic surveying. In Continuous Kinematic surveys, however, the baseline processor can solve for the receiver’s position not only when it is stationary but also for each GPS observation made while the rover is moving. Topographic surveys, for example, can be performed by logging data continuously over a project area, provided proper attention is paid to antenna heights.

Since Continuous Kinematic surveying provides a position for the receiver at every epoch, this technique also can be used to solve for the position of the receiver at a specific time, such as the instance of an event mark. To do this the baseline processor uses one or more positions on either side of the event together with an interpolation strategy to determine the position of the receiver at any specific instance in time. GPS processing styles can be used to control event interpolation using:

  Interpolation Method

  Maximum Allowed Missing Epochs

  Time Offset

NOTE: The baseline processor automatically assigns point names to all the continuous points. This is done is such as way as to ensure that there is not a conflict with points obtained in using RTK continuous techniques.


     New Plot command (SV Plot)

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Select this command to open a new SV Plot window. Multiple SV Plot windows can be opened, tiled, and cascaded. Individual SV Plot windows can be minimized and their icons can be arranged within the SV Plot client area.

To access it, do one of the following from the GPS Signal Plots window:

  Select File / New Plot.

  From the SV Plot toolbar, click [image].

A new client window appears. You can use it to display additional plots.


     Export command (SV Plot)

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Select this command to export the raw satellite tracking data for the active plot to a file. The data table in the file includes one column for every type of raw satellite tracking information included in the active plot.

To access it, do one of the following from the GPS Signal Plots window:

  Select File / Export.

  From the SV Plot toolbar, click [image].

Exported SV Plot files are saved to text files (*.txt files).


     Print command (SV Plot)

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Select this command to print the plot displayed in the currently selected SV Plot window. The plot can be output to a printer or file, depending on options selected from the Print dialog.

To access it, do one of the following from the GPS Signal Plots window:

  Select File / Print.

  From the SV Plot toolbar, click [image].

The Print dialog appears, with options for selecting printing options.

Consider these options:

  You can click OK to immediately print the plots in the active window in portrait mode.

  Choose the Landscape option to rotate the plot 90 degrees on the printed page.

  Choose the File option to write the plots in the active window to a printer file. If you choose the File option and click OK, a dialog will appear to request the file name.

  You can also write the raw satellite information used to generate plots to a file using the Export command. This is useful to documenting the raw satellite tracking information in tabular form. Later you can combine the exported tabular information and plots in reports.


     SV Plot Help command (SV Plot)

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Select this command to display help information about SV Plot commands and operations.

To access it, do one of the following from the GPS Signal Plots window:

  Select Help / SV Plot Help.

  From the SV Plot toolbar, click [image].

SV Plot help appears.


     L1 S-Range command (SV Plot)

More Information

How to ...	See also
Select this command to plot L1 Stationary Range (S-Range) data, in meters, for the selected satellite over the span of the timeline.

To access it, do one of the following:

  Select View / Data / L1 S-Range.

  From the dialog bar, click L1 S-Range.

L1 Stationary Range information is plotted in the active window.


     Azimuth command (SV Plot)

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How to ...	See also
Select this command to plot the azimuth data, in degrees, collected for the selected satellite over the span of the timeline.

To view the Azimuth plot, do one of the following:

  Select View / Data / Azimuth.

  From the dialog bar, click Azimuth.


     Elevation command (SV Plot)

More Information

How to ...	See also
Select this command to plot raw satellite elevation information. Data is plotted in degrees over the span of the timeline.

To view the Elevation plot, do one of the following:

  Select View / Data / Elevation.

  From the dialog bar, click Elevation.

Elevation data is plotted in the active window.


     L1 SNR command (SV Plot)

More Information

How to ...	See also
Select this command to plot the L1 carrier signal-to-noise ratio (SNR) data, collected for the selected satellite over the span of the timeline.

To view the L1 SNR plot, do one of the following:

  Select View / Data / L1 SNR.

  From the dialog bar, click L1 SNR.

L1 signal-to-noise ratio information is plotted in the active window.


     L2 SNR command (SV Plot)

More Information

How to ...	See also
Select this command to plot the L2 carrier signal-to-noise ratio data, collected for the selected satellite over the span of the timeline.

To access it, do one of these actions from the GPS Signal Plots window:

  Select View / Data / L2 SNR.

  From the dialog bar, click L2 SNR.

L2 signal-to-noise ratio information is plotted in the active window.


     L1 Phase command (SV Plot)

More Information

How to ...	See also
Select this command to plot the L1 carrier phase data collected for the selected satellite over the span of the timeline.

To view the L1 Phase plot, do one of the following:

  Select View / Data / L1 Phase.

  From the dialog bar, click L1 Phase.

L1 phase information is plotted in the active window.


     L2 Phase command (SV Plot)

More Information

How to ...	See also
Select this command to plot the L2 carrier phase data collected for the selected satellite over the span of the timeline.

To view the L2 Phase plot, do one of the following:

  Select View / Data / L2 Phase.

  From the dialog bar, click L2 Phase.

L2 phase information is plotted in the active window.


     L1 Doppler command (SV Plot)

More Information

How to ...	See also
Select this command to display the L1 carrier Doppler data, in kHz, collected for the selected satellite over the span of the timeline.

L1 Doppler is the apparent carrier signal frequency offset averaged over a sample measurement interval. It is measured in relation to the nominal L1 carrier frequency of 1575.42 MHz, referenced to the internal receiver clock. L1 Doppler includes all receiver and satellite clock frequency errors. It is expressed in Hertz at the L1 carrier.

To view the L1 Doppler plot, do one of the following:

  Select View / Data / L1 Doppler.

  From the dialog bar, click L1 Doppler.

L1 Doppler information is plotted in the active window.


     L1 Aux, CA command (SV Plot)

More Information

How to ...	See also
Select this command to plot the L1 Auxiliary C/A-code information collected for the selected satellite over the span of the timeline. The menu options and dialog bar buttons for command are not available when no L1 auxiliary C/A information was collected for the satellite.  It is only available for receivers that can track both L1 C/A code and L1 P code simultaneously.

To view the L1 Auxiliary C/A-code information, do one of the following:

  Select View / Data / L1 Aux. CA.

  From the dialog bar, click L1 Aux. CA.

L1 Auxiliary C/A information is plotted in the active window.


     Clock Offset command (SV Plot)

More Information

How to ...	See also
Select this command to plot the clock offset information, in milliseconds, over the span of the timeline.

To view the Clock Offset plot, do one of the following:

  Select View / Data / Clock Offset.

  From the dialog bar, click Clock Offset.

Clock Offset data is plotted in the active window.


     Dialog Bar command (SV Plot)

More Information

How to ...	See also
Select this command to show and hide the dialog bar. The dialog bar includes all commands for plotting raw satellite tracking information.

To show or hide the dialog bar:

  Select View / Dialog Bar.

  Press Alt+VD.

These dialog bar buttons are available:

  Azimuth

  Elevation

  L1 Range

  L1 S/N

  L2 S/N

  L1 Phase

  L2 Phase

  L1 Doppler

  L1 Aux. CA

  Clock Offset

NOTE:  These buttons duplicate the command on the SV Plot menu.

TIP: You can dock and undock the dialog bar. The dialog bar can be docked to the area next to the SV Plot toolbar or to the area below the status bar.


     Toolbar command (SV Plot)

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Select this command to show and hide the SV Plot toolbar.

To show or hide the SV Plot toolbar:

  Select View / Toolbar.

  Press Alt+VT.

The toolbar is shown or hidden each time you select this command.


     Data command (SV Plot)

More Information

How to ...	See also

Select this command to show a submenu of plotting commands. Individual commands plot a specific type of raw satellite tracking information.

To view the Data submenu:

  Select View / Data

A submenu appears with these commands:

  Azimuth

  Elevation

  L1 Range

  L1 S/N

  L2 S/N

  L1 Phase

  L2 Phase

  L1 Doppler

  L1 Aux. CA

  Clock Offset

NOTE:  These commands duplicate the command buttons on the SV Plot dialog bar.


     Exit command (SV Plot)

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Select this command to end a SV Plot viewing session.

To select the Exit command, do one of the following:

  Select File / Exit.

The SV Plot closes.


     Using Help command (SV Plot)

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 See also

Select this command to display the Windows help system on using help.

To view Windows help system on Using Help, do one of the following:

  Select Help / Using Help.

The Windows help system on Using Help appears.


     Index command (SV Plot)

Select this command to start the Trimble Geomatics Office software’s help system.

To view the Trimble Geomatics Office Help, do one of the following:

  Select Help / Index.

The opening topic for the help system appears.


     Printing Plots

The graphical image of a plot can be output to a printer or a printer file.

By default, plots are printed in Portrait mode. You can select Landscape from the Printer Setup dialog to rotate the plots 90 degrees.

TIP: You can also export the satellite tracking data associated with a plot to a file, open the file in a text editor, and print the data. This could be useful for documenting printed plots.


     Exporting Plot Data

Sets of plotted satellite tracking data can be displayed in a plot window and exported to a file.

The following is an excerpt of the first few lines of a file containing L1 and L2 Signal-to-Noise Ratio plot data:

Timeline Satellite Data Export for Satellite SV 1 in file 29932370.DAT

Time                       	       L1 S/N   L2 S/N

14:05:25.0  1998/09/10       52.75     38.00

14:05:30.0  1998/09/10       52.25     38.50

NOTE: Additional columns are added to exported files when more data types are included in the same plot window.


     Analyzing Plots

More Information

 See also

Plots of satellite tracking, displayed in one or more SV Plot windows, can be visually analyzed for discrepancies. This is useful for identifying problems the receiver may have had tracking one or more satellites.  In some cases it may help to disable all, or portions of, the measurements from one or more satellites.


     Displaying SV Plots

More Information

 See also

Plots of collected satellite tracking data can be displayed using menu or dialog bar commands.

You can do the following when viewing plots:

  Display multiple types of collected satellite tracking data within the same window.

  Open multiple windows, each displaying one or more types of collected satellite tracking data.

  Use the mouse to point to data areas of a plot, and read the status bar indicators to learn the value and collection time of the data

  Visually analyze two or more types of collected tracking data to look for discrepancies.

  Tile and cascade windows.

  Minimize and maximize windows.

  Arrange minimized window icons.

  Resize, move, and restore windows using standard Windows commands.

  Close client windows at any time.

  Minimize and maximize the SV Plot window. When minimized, the icon appears in the Windows task bar.


SV Plot - Overview
     SV Plot − Overview

View SV Plot to analyze plots of raw satellite tracking information collected for a satellite selected in Timeline.

The application window can be minimized, maximized, and exited like any Windows application. When minimized, the SV Plot icon appears in the Windows taskbar.

You can plot one or more types of raw satellite tracking information in the window simultaneously, and use the plots as a diagnostic tool for analyzing the raw satellite data collected during observation spans.

The plots are active when data is displayed. You can move your mouse across the plots and the read value and collection time of the data. The position of the mouse cursor as it hovers over the plot determines the content of the status bar indicator panes.

For more information about the SV Plot, see these topics:

  SV Plot Window

  SV Plot Commands

These operations can be performed while working with SV Plot windows:

  Displaying Plots

  Analyzing Plots

  Exporting Plot Data

  Printing Plots


SV Plot Commands - Overview
     SV Plot Commands − Overview

All SV Plot commands are accessible from the menu. Some commands are also accessible from the toolbar and dialog bar. Many commands have keyboard shortcuts.

These commands are available from the GPS Signal Plot window:

File Commands

  New Plot

  Export…

  Print…

  Print Setup

  Exit

View Commands

  Data

  Toolbar

  Dialog Bar

Window Commands

  Cascade

  Tile

  Arrange Icons

Help Commands

  SV Plot Help

  Index

  Using Help

  About Timeline


SV Plot Window - Overview
     SV Plot Window − Overview

More Information

Dialog	See also
Overview

Use this window to plot and visually analyze raw satellite tracking information collected during an observation versus time spans for the selected satellite and active survey. SV Plot has its own menu, status bar, toolbar, dialog bar, and plot windows. Multiple plot windows with separate sets of satellite tracking plots can be displayed, minimized, and maximized. Standard Windows commands can be used to resize, restore and move these windows.

A number of SV Plot commands are supported, including commands for printing plots and exporting plot data.

For more information, see these topics:

  SV Plot Menu

  SV Plot Status Bar

  SV Plot Toolbar

  SV Plot Dialog Bar

  SV Plot Windows


     SV Plot Windows

More Information

 See also

Multiple plots can be displayed in the same window or new windows can be opened to display separate plots or selections of plots.

Consider these guidelines:

  New windows can be opened and individual plots or multiple plots can be displayed in the same window.

  Windows commands can be selected from the Windows or Control menus to minimize, maximize, close, restore, and resize windows.

  Windows commands can be used to tile and cascade windows and arrange window icons.

  The plot in the active window can be output to a printer or file.

  The data used to generate plots also can be exported to a file in tabular format. This file can be printed later using any text editor.


     SV Plot Menu

Overview and More Information
Use the menu to execute commands for viewing, printing and exporting raw satellite tracking data plots.

All SV Plot commands are accessible from the menu. Some commands are also accessible from the toolbar and dialog bar. Many commands have keyboard shortcuts.

These commands are available from the GPS Signal Plot window:

File Commands

  New Plot

  Export…

  Print…

  Print Setup

  Exit

View Commands

  Data

  Toolbar

  Dialog Bar

Window Commands

  Cascade

  Tile

  Arrange Icons

Help Commands

  SV Plot Help

  Index

  Using Help


     SV Plot Toolbar

Overview and More Information
Use the toolbar to open new plot windows, export data, print plots, and display help.

These commands are available:

	New Plot Window
	Export Data to File
	Print Plot


     SV Plot Status Bar

Overview and More Information
The status bar shows the observed value and the time corresponding to the position of the mouse cursor in the window.

You can use the mouse to identify when an observation value was recorded over the observation time span.

Message Indicator Pane

SV Plot command messages are displayed in this indicator pane. When the selection bar appears over a menu command or the mouse points to a toolbar or dialog bar button, more detailed information about the command is displayed in this pane.

Tracking Data Indicator Pane

The value appearing in this indicator pane varies and depends on the type of data displayed in the plot and the current mouse location.

This indicator is automatically updated with the units of measurement applicable to a particular data type when multiple types of satellite tracking data are plotted in the same window. You can use the legend at the bottom of a plot to learn the units of measurement for the satellite data appearing in the plot. The current location of the mouse cursor as it hovers over plotted data determines the unit of measurement appearing in the indicator.

Time Indicator Pane

The time when the satellite tracking data was collected is displayed in this pane. Time values are displayed in GPS week/seconds or Windows local time. You can change the time format from the Time Options dialog.


     SV Plot Dialog Bar

Overview and More Information
Use the dialog bar buttons to plot the value of raw satellite tracking data collected over the observation period for the selected satellite and active survey.

To plot data:

  Click on any combination of the buttons on the dialog bar.

You can move the mouse over any observation value on the plot and read the status bar to learn the observation time and value of the raw satellite tracking data.

TIP: You can dock and undock the dialog bar. The dialog bar can be docked to the area on the right of the toolbar or to the area below the status bar.

These dialog bar buttons are available:

L1 S-Range

Use this button to plot the tracked L1 Stationary Range of the satellite, in meters, collected over the observation time. For more information, see L1 S-Range command.

Azimuth

Use this button to plot the tracked azimuth data, in degrees, of the satellite collected over the observation time. For more information, see Azimuth command.

Elevation

Use this button to plot the tracked elevation data, in degrees, of the satellite collected over the observation time. For more information, see Elevation command.

L1 SNR

Use this button to plot the tracked L1 carrier signal-to-noise ratio data, collected over the observation time. For more information, see L1 SNR command.

L2 SNR

Use this button to plot the tracked L2 carrier signal-to-noise ratio data, collected over the observation time. For more information, see L2 SNR command.

L1 Phase

Use this button to plot the tracked L1 carrier phase data, in cycles, collected over the observation time. For more information, see L1 Phase command.

L2 Phase

Use this button to plot the tracked L2 carrier phase data, in cycles, collected over the observation time. For more information, see L2 Phase command.

L1 Doppler

Use this button to plot the tracked L1 Doppler, in kHz, over the observation time. For more information, see L1 Doppler command.

L1 Aux C/A

For more information, see L1 Aux. C/A command.

Clock Offset

Use this button to plot the clock offset, in milliseconds, over the observation time. For more information, see Clock Offset command.


     Continuous command (Timeline)

More Information

How to ...	See also
Select this command to filter the continuous segments displayed in the Time Span Viewer.

To filter the continuous segments from the Time Span Viewer:

1.	Right-click the Time Span Viewer background.

2.	Select View Filters / Continuous.

The occupation segments are shown or hidden.

To filter the continuous segments:

1.	Click the Time Span Viewer background.

2.	From the Timeline toolbar, click [image].

The occupation segments are shown or hidden.


     Delete command (Timeline)

More Information

 See also

Select this command to delete a Survey or Occupation element in Timeline. Since these Timeline elements represent project data, all references to the associated data in the project are removed.

To select the Delete command from the Time Span Viewer:

1.	Right-click the Survey or Occupation element.

2.	Select Delete.

To select the Delete command from Survey View:

1.	Click the Survey or Occupation element.

2.	Do one of the following:

  Select Edit / Delete.

  Press Del.

The Survey or Occupation data associated with the element is deleted, and the element’s appearance changes to a rectangle with a black border to signify data once existed at this location on the timeline. Deleted data is removed from the project and can no longer be accessed.

CAUTION: Consider the effects of deleting Survey or Occupation data from the project.


     DOP Plot command (Timeline)

More Information

 See also

Select this command to view the DOP Plot display. This command is only available when an occupation is selected in the Time Span Viewer.

To view a DOP Plot from the Occupation menu:

1.	Right-click the Occupation element.

2.	Select Ephemeris Info / DOP Plot.

The DOP Plot display appears.

To view DOP Plot from the Plot toolbar:

1.	Click the Occupation element.

2.	From the Plot toolbar, click [image].

The DOP Plot display appears.


     Enable/Disable command (Timeline)

More Information

How to ...	See also
Select this command to enable or disable Timeline elements. Since Timeline elements represent actual project data, the data is also enabled or disabled.

This command is especially useful for disabling problematic data when performing trial-and-error tests to improve baseline solution quality. If you find no improvement in baseline processing results after disabling an element, re-enable that element.

This command is also available when editing small regions of GPS observations, such as areas containing large numbers of cycle slips.

NOTE: Satellites, GPS observations, and selected regions of GPS observations can be disabled and enabled. Some Timeline elements are protected and cannot be disabled directly—they are only disabled when their parent elements are disabled. These protected elements include Ephemeris icons and Station icons.

To select the Disable/Enable command from the Time Span Viewer:

1.	Select the Satellite Icon or GPS Observation element.

2.	Right-click the element.

A menu containing the Disable/Enable command appears.

To select the Disable/Enable command from a selected region within a GPS observation:

1.	Drag a selection rectangle around the GPS Observation region.

2.	Right-click within the selection rectangle.

A menu containing the Disable/Enable command appears.

To select the Disable/Enable command from a selection of GPS observations:

1.	Drag a selection rectangle around the region of GPS Observation elements.

2.	Right-click within the selection rectangle.

A menu containing the Disable/Enable command appears.


     Ephemeris command (Timeline)

More Information

How to ...	See also
Select this command to filter the Ephemeris icons displayed in the Time Span Viewer. Each time this command is executed, the Ephemeris icons are shown or hidden.

To filter Ephemeris icons from the Time Span Viewer:

1.	Right-click the Time Span Viewer background.

2.	Select View Filters.

A submenu containing the Ephemeris command appears.

To filter Ephemeris icon:

1.	Click the Time Span Viewer background.

2.	From the Timeline toolbar, click [image].


     Ephemeris Info command (Timeline)

More Information

How to ...	See also
Select this command to view a submenu with options for viewing the DOP Plot and Skyplot for a selected occupation.

To view the Ephemeris Info submenu:

1.	Select the Occupation element. The occupation is highlighted.

2.	Right-click the occupation.

A menu containing the Ephemeris Info command appears.

These submenu commands are available:

  DOP Plot

  Skyplot

NOTE: The above commands are also available from the Plot toolbar.


     Expand All command (Timeline)

More Information

How to ...	See also
Select this command to open all data folders in the Timeline control bar.

NOTE: At least one data folder must be closed before this command becomes available.

To select the Expand All command from the control bar:

  Right-click the control bar background or a data folder. A menu containing the Expand All command appears.

To select the Expand All command from the Timeline toolbar:

1.	Click the control bar background or a data folder.

2.	From the Timeline toolbar, click [image].

TIP: You can also open individual data folders by clicking [image] on the data folder.


     Next command (Timeline)

More Information

How to ...	See also
Select this command to pan the Time Span Viewer to the next Survey element. Select this command several times to quickly pan the Time Span Viewer to each successive Survey element in the data folder.

To select the Next command from the Time Span Viewer:

  Right-click the Time Span Viewer background. A menu containing the Next command appears.

To select the Next command from the Timeline toolbar:

1.	Click the Time Span Viewer background, a Survey element, or Occupation element.

2.	On the Timeline toolbar, click [image].

TIP: You can also take the direct route when panning to an occupation element. For example, you can view a baseline's properties from the Survey view and select an occupation from the Selection list. This pans the Time Span Viewer to the selected occupation and highlights it.

TIP: You can also use the Zoom Extents command to view the entire timeline, select the desired occupation, and use the Zoom to Span command to view it in the Time Span Viewer.


     Previous command (Timeline)

More Information

How to ...	See also
Select this command to pan the Time Span Viewer to the previous occupation end point. Select this command several times to quickly pan the Time Span Viewer to each successive occupation in the survey data.

To select the Previous command from the Time Span Viewer:

  Right-click the Time Span Viewer background, a Survey rectangle, or Occupation element. A menu containing the Previous command appears.

To select the Previous command from the Timeline toolbar:

1.	Click the Time Span Viewer background, a Survey element, or Occupation element.

2.	On the Timeline toolbar, click [image].

TIP: You can also take the direct route when panning to a occupation element. For example, you can view a baseline's properties from the Survey View window and select a occupation from the Selection list. This pans the Time Span Viewer to the selected occupation and highlights it.

TIP: You can also use the Zoom Extents command to view the entire timeline, select the desired occupation, and use the Zoom to Span command to view it in the Time Span Viewer.


     Satellites command (Timeline)

More Information

How to ...	See also
Select this command to filter all GPS observations appearing in the Time Span Viewer. Each time this command is executed, it shows or hides the GPS Observations.

To filter GPS observations from the Time Span Viewer:

1.	Right-click the Time Span Viewer background.

2.	Select View Filters.

A submenu containing the Satellites command appears.

To filter GPS observations from the Timeline toolbar:

1.	Click the Time Span Viewer background.

2.	From the Timeline toolbar, click [image].

All Ephemeris icons, associated with the GPS observations, are also shown or hidden when this command is executed.


     Shrink All command (Timeline)

More Information

How to ...	See also
Select this command to close all open data folders in the Timeline control bar.

NOTE: At least one data folder must be open before this command becomes available.

To select the Shrink All command from the control bar:

  Right-click the control bar background or a data folder. A menu containing the Shrink All command appears.

To select the Shrink All command from the Timeline toolbar:

1.	Click the control bar background or a data folder.

2.	From the Timeline toolbar, click [image].

TIP: You can also close individual data folders by clicking the [image] symbol on the folder.


    Skyplot command (Timeline)

More Information

 See also

Select this command to view a Skyplot. This command is only available when an Occupation element is selected from the Time Span Viewer. The Skyplot display shows a local-horizon plot of the satellite constellation visible from the selected point at the time of the occupation. Satellite positions are calculated from ephemeris information that was current at the time of the observation, and are displayed in terms of azimuth and elevation.

To view an occupation’s Skyplot:

1.	To open the data folders, do one of the following:

  From the control bar, open a data folder using one of these actions.

  Click [image] on the data folder.

  Right-click the data folder and select Expand All.

  From the Timeline toolbar, click [image].

The first action displays Satellite icons for the selected data folder. The two alternate actions expand all data folders.

2.	Select the Occupation element.

3.	To select the Skyplot command, do one of the following:

  Right-click the Occupation to display and select Ephemeris Info to display a submenu with the Skyplot command.

  From the Plot toolbar, click [image].


     SV Plot command (Timeline)

More Information

 See also

Select this command to view the SV Plot display. SV Plot includes commands for viewing and printing selected satellite tracking information. It also is useful for analyzing raw satellite tracking information for individual satellites. This command is only available when a Satellite icon is selected from the control bar.

To view SV Plot:

1.	To open the data folders, do one of the following:

  From the control bar, open a data folder using one of these actions:

  Click [image] on the desired data folder.

  Right-click the data folder and select Expand All.

  From the Timeline toolbar, click [image].

The first action displays Satellite icons for the selected data folder. The two alternate actions open one or more data folders.

2.	Select the desired Satellite icon.

3.	To select the SV Plot command, do one of the following:

  Right-click the Satellite icon to display a menu with the SV Plot command.

  From the Timeline toolbar, click [image].


     Time Options command (Timeline)

More Information

Dialog	See also
Select this command to display the Time Options dialog with options for selecting the time format used to display time in the Time Ruler, Timeline properties dialogs, SV Plot, Skyplot, DOP Plot, and the Survey View status bar.

To view the dialog, do one of the following:

  Double-click the Time Ruler.

  Right-click the Time Ruler to display a menu with the Time Options command.


     View Filters command (Timeline)

More Information

How to ...	See also
Select this command to display the submenu of commands used to filter the information appearing in the Time Span Viewer:

1.	Right-click the Time Span Viewer background.

2.	Select View Filters from the menu.

A submenu of commands appears.

These commands are available:

  Continuous

  Satellites

  Ephemeris

NOTE: This command is not available on the Timeline toolbar, but the individual commands on the submenu are available.


    Zoom In command (Timeline)

More Information

 See also

Select this command to zoom the Time Span Viewer by 200%. The Start and End Fields in the Time Ruler are updated to reflect the shorter time span.

To select the Zoom In command from the Time Span Viewer:

  Right-click the Time Span Viewer background. A menu containing the Zoom In command appears.

To select the Zoom In command from the Survey view:

1.	Click the Time Span Viewer background.

2.	To select the Zoom In command, do one of the following:

  Select View / Zoom to display a submenu with the Zoom In command.

  From the View Control toolbar, click [image].


     Zoom Extents command (Timeline)

More Information

 See also

Select this command to zoom the Time Span Viewer out to view the entire timeline. This command is useful for showing the time span occupied by a Timeline element in relation to the overall timeline. You can use this command and then use the Zoom Previous command to return to your original magnification level.

To select the Zoom Extents command from the Timeline view area:

  Right-click a Timeline element or window background.

A menu containing the Zoom Extents command appears.

To select the Zoom Extents command from the Survey view:

1.	Click a Timeline element or the Time Span Viewer background.

2.	Select View / Zoom to display a submenu with the Zoom Extents command.


    Zoom Out command (Timeline)

More Information

 See also

Select this command to zoom out the Time Span Viewer by 50%. The Start and End Time fields in the Time Ruler are updated to reflect the longer time span.

To select the Zoom Out command from Timeline:

  Right-click the Time Span Viewer background. A menu containing the Zoom Out command appears.

To select the Zoom Out command from the Survey view:

1.	Click the Time Span Viewer background.

2.	Do one of the following:

  Select View / Zoom to display a submenu with the Zoom Out command.

  From the View Control toolbar, click [image].


     Zoom Previous command (Timeline)

More Information

 See also

Select this command to zoom to the previous magnification.

To select the Zoom Previous command from the Timeline view area:

  Right-click a Timeline element. A menu containing the Zoom Previous command appears.

To select the Zoom Previous command from the Survey view:

1.	Click a Timeline element.

2.	To select the command, do one of the following:

  Select View / Zoom to display a submenu with the Zoom Previous command.

  From the View Control toolbar, click [image].


     Zoom to Span command (Timeline)

More Information

 See also

Select this command to zoom the time span of a selected Timeline element to the width of the Time Span Viewer.

To zoom the element to fill the Time Span Viewer:

1.	Select a Timeline element.

2.	Right-click the element.

3.	Select Zoom to Span.


     Events command (Timeline)

More Information

How to ...	See also
Select this command to view Event icons in the Time Span Viewer:

  From the Timeline toolbar, click [image]. The Event icons appear in the Time Span Viewer if events are included in the data.


     Properties command (Timeline)

More Information

How to ...	Dialog
Select this command to display the properties dialog for the selected Timeline element:

1.	Right-click the Timeline element.

2.	Select Properties. The applicable properties dialog is displayed.

Properties commands exist for these dialogs:

  Receiver Properties

  GPS Observation

  Survey

  Static Occupation

  Continuous Occupation Segment

  Ephemeris Icon

TIP: You can also double-click on a Timeline element to view its properties.


     Planning Plots command (Timeline)

Select this command to show or hide the Planning Plots toolbar:

  Select View / Toolbars / Planning Plots. The Planning Plot toolbar is shown or hidden each time the command is executed.


     Timeline command (Toolbars)

Select this command to show or hide the Timeline toolbar:

  Select View / Toolbars / Timeline. The Timeline toolbar is shown or hidden each time the command is executed.


     Stations command (Timeline)

More Information

How to ...	See also
The small red triangular Station icons and labels displayed to identify Static Occupations. can be filtered:

1.	View Timeline.

2.	From the Timeline toolbar, click [image].

Each time the Stations command is executed, the Station icons are turned on or off.

NOTE: Station Icons cannot be deleted or disabled—they are only deleted or disabled with their parent occupation.


     Select All command (Timeline)

More Information

How to ...	See also
Select this command from a Time Span Editing field to select all data in the fields that contain the time and date of the observations. This is useful for selecting all data before cutting or copying the data to the clipboard.

To select all data in a Time Span Editing field:

1.	Click the Start or Stop Time Span Editing field.

2.	Right-click and choose Select All.

All data in the field is selected.


    Receiver Properties dialog

More Information

Overview and More Information
Use this dialog to learn general information about the receiver used to collect the survey data. All fields are read-only data, obtained from the downloaded receiver information records, or from the header records in a RINEX file.

To view the Receiver Properties dialog:

  Double-click a data folder. The Receiver Properties dialog appears with these read-only fields:

Serial Number

This field shows the receiver serial number.

Receiver Type

This field shows the receiver model.


    Survey Properties dialog

More Information

Dialog	See also
Use this dialog to view information about individual survey data logging sessions.

To open the Survey Properties dialog, do one of the following:

  Double-click on the Survey element.

  Right-click on the Survey element, and select Properties.

These data fields are available:

Session ID

This field shows the name of the survey session. Type a new Session ID if you want to identify the session in a new way. This is the only editable field in this dialog.

Data File Name

This field shows the name of the file associated the survey.

Start Time

This field shows the Survey session start time in Windows local time of GPS Week/Seconds. The time format is dependent on the current Time Options setting.

Stop Time

This field shows the Survey session end time in Windows local time of GPS Week/Seconds. The time format is dependent on the current Time Option setting.

Nav Processor Version

This field shows the firmware version of the receiver Navigation Processor (Trimble receivers only).

Epoch Rate

This field shows the minimum synchronization rate, in seconds, used to collect the data for the survey session.

Signal Processor Version

This field shows the firmware version of the receiver Signal Processor (Trimble receivers only).

Elev Mask

This field shows the elevation mask in effect when the survey data was collected.

DC Type

This field shows data collector and version number of the survey controller, if a survey data was used in the survey.


Occupation/Data Segment dialog - Overview
    Occupation/Data Segment dialog − Overview

More Information

How to ...	Dialog	See also
Use this dialog to view and edit all information pertaining to both Static Occupations and Continuous and Roving Segments. A separate dialog can be opened for each segment, allowing you to compare the data for multiple segments.

To view the Occupation/Data Segment dialog, do one of the following:

  Double-click an Occupation element.

  Right-click an Occupation element, and select Properties.

These two tabs are available:

  Segment

  Antenna

In the upper-right corner of the Occupation/Data Segment dialog is a left-right spin button. If the survey includes multiple occupations, use these spin buttons to display information from the next or previous occupation. If the dialog for the next occupation is displayed in another properties dialog and the right-arrow button is pressed, that occupation is skipped.


Occupation/Data Segment dialog - Segment tab
    Occupation/Data Segment dialog − Segment tab

More Information

How to ...	Dialog	See also
The Segment tab displays overall occupation information for editing.

To view the Segment tab, do one of the following:

  Double-click Occupation element.

  Right-click an Occupation element, and select Properties

The Occupation/Data Segment Properties dialog appears with the Segment tab displayed.

These fields or controls are available:

Point Name

Read this field to learn the name of the point at which the occupation occurred. This field will be blank for Roving and Continuous segments.

Segment Type

Select an option from this list to change the segment to one of these types:

  Static Occupation

  FastStatic Occupation

  Stop&Go Occupation

  Roving Segment

  Continuous Segment

NOTE: The Static and FastStatic options may or may not appear, depending on the type of data available in the file.

WARNING: Changing the designation of an occupation to Roving or Continuous should only be done with caution. If a Static Occupation is changed to continuous, the station reference to the station for that occupation is deleted.

Start Time

Edit this field to change start time of the occupation. The time is displayed in Windows local time or GPS Week/Seconds, depending on the current Time Options setting.

Stop Time

Edit this field to change the stop time of the occupation. The time is displayed in Windows local time or GPS Week/Seconds, depending on the current Time Options setting.

TIP: Start and stop times can also be edited by selecting the occupation element in the Time Span Viewer and changing the Start and End Time fields in the Time Ruler.


Occupation/Data Segment dialog - Antenna tab
    Occupation/Data Segment dialog − Antenna tab

More Information

How to ...	Dialog	See also
Use this tab to adjust the height of the antenna (in meters), the type of antenna, and the measurement type.

To view the Antenna properties:

1.	To open the Occupation/Data Segment dialog, do one of the following:

  Double-click an Occupation element.

  Right-click an Occupation element, and select Properties.

The Occupation/Data Segment dialog appears.

2.	Click Antenna.

The Antenna properties appear.

Antenna Height

Use this field to view or edit the measured height of the antenna.

Type

Use this field to view or select the type of antenna connected to the receiver.

Measurement To

Use this field to view or select the method used to measure the height of the antenna.

Below the Measured To field is a group of radio buttons that control how the antenna information is applied. These include:

  Use for this measurement only applies the changes only to the selected occupation or segment. This is the default setting.

  Use for this and subsequent measurements in this session applies the changes to the selected occupation or segment, and all subsequent occupations and segments through the end of the Survey element.

  Use for all measurements in this session applies the changes to all occupations and segments in the Survey element.


    GPS Observation Properties dialog

More Information

How to ...	Dialog	See also
Use this dialog to view the observation types available for a selected GPS Observation element(s).

To view the GPS Observation Properties dialog:

1.	To open the data folders in the control bar, do one of the following:

  Right-click the data folder, and select Expand All.

  From the Timeline toolbar, click

  From a data folder, click the [image] symbol.

All GPS Observations in the Time Span Viewer and all SV Icons in the control bar appear.

TIP: These elements can be hidden at any time by clicking [image] from the Timeline toolbar or by right-clicking the data folder and selecting Shrink All from the menu. You can also close individual folders by clicking [image].

2.	To display the properties dialog, do one of the following:

  Double-click a GPS Observation element.

  Right-click a GPS Observation element, and select Properties.

The GPS Observation Properties dialog appears.

These fields are available:

Start

Edit this field to change the starting time of the selected GPS Observation. The time appearing in this field is initially based on the current GPS observation selection in the Time Span Viewer. Any changes applied to the GPS observation data are based on this start time. If you change the start time in this field, all changes are applied to all satellites currently selected from the Satellites to Edit list or the GPS observation region(s) selected in the Time Span Viewer.

Stop

Edit this field to change the ending time of the selected GPS Observation. The time appearing in this field is based on the current GPS observation selection in the Time Span Viewer. Any changes applied to the GPS observation data are based on this stop time. If you change the stop time in this field, all changes are applied to all satellites currently selected from the Satellites to Edit list or the GPS observation region(s) selected in the Time Span Viewer.

Observation Types

Use this control group to disable and enable the Observation Types included in GPS observations. Each Observation Type is one form of raw satellite information.

These Observation Type check boxes are available:

  L1 Phase

  L1 P-Code

  L1 C/A-Code

  L2 Full Phase

  L2 Half Phase

  L2 P-Code

  L2 Encrypted

Consider these guidelines when viewing or editing Observation Types:

  A check mark for an Observation Type indicates the data is used, while a cleared check box indicates the data type is not included.

  A gray check mark indicates both enabled and disabled spans are within the GPS Observation, and no operation is to be performed on the Observation Type.

  Dimmed text adjoining a check mark indicates that the Observation Type is not available.

  Clear check marks to disable selected data.

Reset

Click this button to reset all Observation Types check boxes to their original state—that is, the state when the observation data was collected in the field.

Satellites to Edit

Select check boxes in this list to select the satellites and their associated raw GPS observation data to edit.

NOTE: When multiple satellites are selected from this list, changes in properties are applied to all GPS observations over the time span selected from this properties dialog.

TIP: GPS observations can also be selected directly in the Time Span Viewer by dragging a selection rectangle around a group of GPS observations or around a small region of a GPS observation. For more information, see Selecting and Editing GPS Observations.

Enable All

Click this button to enable all available Observation Types for the satellites selected from the Satellites to Edit list over the time span defined by the Start and Stop fields.

Disable All

Click this button to disable all available Observation Types for the satellites selected from the Satellites to Edit list over the time span defined by the Start and Stop fields.


    L1 Phase

Overview and More Information
This Observation Type is available when the receiver is able to recover L1 Phase measurements. Single-frequency or dual-frequency receivers can track this data.

If set, the check box can be cleared (for individual satellites, selections of satellites, or areas of GPS observation elements) to disable the L1 Phase data.


    L1 P-Code

Overview and More Information
This Observation Type is available when L1 P-Code is tracked on the L1 carrier. Most current dual-frequency receivers and select single-frequency receivers can track this data when Anti-spoofing is is turned off.

If set, the check box can be cleared (for individual satellites, selections of satellites, or areas of GPS observation elements) to disable the L1 P-Code data.


    L1 C/A-Code

Overview and More Information
This Observation Type is available when Coarse/Acquisition Code is tracked on the L1 carrier. Single-frequency or dual-frequency receivers can track this data.

If set, the check box can be cleared for individual satellites, selections of satellites, or selected areas of GPS observations to disable the L1 C/A-Code data.


    L2 Full Phase

Overview and More Information
This Observation Type is available when the GPS receiver is able to recover Full Phase L2 Carrier Phase measurements. Most current dual-frequency receivers can collect this data.

If set, the check box can be cleared (for individual satellites, selections of satellites, or selected areas of a GPS observation element) to disable the L2 Full Phase data.


    L2 Half Phase

Overview and More Information
This Observation Type is available when the receiver can only recover Half Phase L2 Carrier Phase measurements. Some dual-frequency receivers can collect this data.

If set, the check box can be cleared for individual satellites or selections of satellites to disable the L2 Half Phase data.


    L2 P-Code

Overview and More Information
This Observation Type is available when L2 P-Code is tracked on the L2 carrier. Most current dual-frequency receivers can collect this data when Anti-spoofing (A/S) is turned off.

If set, the check box can be cleared (for individual satellites, selections of satellites, or areas of GPS observation elements) to disable the L2 P-Code data.


    L2 Encrypted

Overview and More Information
This Observation Type is available when the L2 P-Code is encrypted during times when Anti-spoofing (A/S) is turned on.  Trimble receivers use proprietary techniques that provide the benefits of tracking code on L2, even during periods of encryption.  The measurements available through these proprietary techniques are called L2 Encrypted.

If set, the check box can be cleared (for individual satellites, selections of satellites, or areas of GPS observation elements) to disable the L2 Encrypted data.


    Satellite Ephemeris Properties dialog

More Information

How to ...	Dialog	See also
Use this dialog to view the satellite ephemeris information periodically broadcast to GPS users. This information is derived from satellite data and cannot be edited.

To view the Satellite Ephemeris Properties dialog:

1.	To view the Ephemeris icons, do one of the following:

  From the Timeline toolbar, click [image].

  Right-click the Time Span Viewer, and select Filter / Ephemeris.

Blue Ephemeris Icons appear on the SV tracking information.

2.	To view the Ephemeris properties, do one of the following:

  Double-click the Ephemeris icon for the desired satellite.

  Right click the Ephemeris icon for the desired satellite, and select Properties.

The Satellite Ephemeris Information dialog opens.

These options are available:

Satellite

This field shows the satellite PRN identifier assigned to the satellite.

Time of Collection

This field shows the GPS Week/Seconds or Local time when the broadcast ephemeris was collected from the satellite. The time format is dependent on the current Time Options setting.

IODC

This field shows the Issue of Data, Clock value included in the broadcast ephemeris.

Time of Ephemeris

This field shows the GPS Week/Seconds or Local time when the ephemeris was issued. The time format is dependent on the current Time Options setting.

Time from Epoch

This field shows the time from the Ephemeris Reference Epoch, rounded to the nearest minute.

GPS Week

This field shows the GPS week when the ephemeris was collected.

GPS week 0 (zero) began on January 6th 1980. A GPS Week Cycle is 1,024 weeks (0 − 1023) or 7,168 days. The GPS Week Cycle rolled over at midnight August 21, 1999. At this time, the GPS Week broadcast by the satellites rolled over to week 0 (zero). Trimble receivers, however, maintain a continuous week count internally.

GPS seconds roll over to zero at Saturday midnight of each GPS Week, correlated to UTC.

URA

This field shows the User Range Accuracy of the satellite, converted to meters. URA is a ranging accuracy indicator of the quality of the satellite data.

URA Alert

This field lets you know if the User Range Accuracy Alert flag is turned on or off for the satellite. This flag is set when the range accuracy may be worse than the value indicated by the URA.

Health

This field shows the health message included for the satellite in the ephemeris. The Health message is an indicator of the quality of the signals broadcast from the satellite. The satellite is in good health when this field reads:

All SV Data OK.

A number of other values could be displayed, and these generally imply poorer satellite health. For more information about these messages, acquire a copy of the ICD-GPS-200 publication referenced in the Bibliography.

A/S

This field lets you know if the Anti-Spoofing mode flag is turned on or off for the satellite.


    Time Options dialog

More Information

How to ...	Dialog
Use this dialog to select the time format for displaying time spans within the Time Ruler and the time appearing in all Timeline dialogs, displays, and the status bar.

To view the Time Options dialog, do one of the following:

  Double-click in the Time Ruler.

  Right-click the Time Ruler, and select Time Options.

The Time Options dialog appears.

These options are available:

Local Time

Select this field to display time in Windows local time format.

GPS Weeks/Seconds

Select this field to display time in GPS week/seconds.

GPS week 0 (zero) began on January 6th 1980. A GPS Week Cycle is 1,024 weeks (0 − 1023) or 7,168 days. The GPS week cycle rolled over at midnight August 21, 1999. At this time, the GPS week broadcast by the satellites rolled over to week 0 (zero). Trimble receivers, however, maintain a continuous week count internally.

GPS seconds roll over to zero at Saturday midnight of each GPS week, correlated to UTC.


    Continuous Segments

More Information

How to ...	Dialog	See also
Continuous Segments represent spans of time when the receiver collects data continuously as it moves. The intent of a Continuous Segment is to process a baseline from the base to the receiver at each measurement cycle. It differs from a Roving Segment only in the fact that a Roving Segment is not intended to be processed. Continuous Segments initially do not have a point association before processing. Once processing is complete, however, a point is generated and stored in the project for every receiver measurement cycle, thus displaying the path of the receiver in Survey view.

Double-click a Continuous Segment element to view or edit its properties.

You can right-click anywhere within the Segment element to view a menu of commands for working with Segment data.

The Continuous Segment time span can be adjusted. A Continuous Segment also can be changed to a Roving Segment so that no processing occurs.

Because the Graphics window and Timeline are linked together, the occupations of points and baselines selected in the Graphics window are selected in Timeline and vice versa. For example, you can select a Continuous Segment in Timeline to see its associated points and baselines selected in the Graphics window. Once the points or baseline are selected, you can view their properties to learn more about the occupation.

Two plots with information about the satellite constellation for the time of the occupation or segment can be displayed when a continuous segment is selected. For more information, see these topics:

  DOP Plot

  Skyplot

TIP: The Properties window, accessed from the Graphics window, is also useful for navigating through Timeline to find selected occupations. The occupations of baselines and points selected from this dialog are also selected in Timeline. Once selected, you can double-click on the occupation element in Timeline to read its properties.

Occupation and Segment elements are displayed in color-coded rectangles for easy identification. For more information, see Occupation Color Coding Scheme.


    Time Span Viewer

More Information

How to ...	Dialog	See also
Think of the Time Span Viewer as a magnifying glass—it can view the entire timeline or can be panned or zoomed to display small spans of the timeline.

Timeline offers several options for zooming and panning the Time Span Viewer to selected information on the timeline. Elements, such as Occupation and GPS observation elements, can be displayed in the Time Span Viewer in two ways:

  Select a zooming command:

  Zoom In

  Zoom Out

  Zoom Extents

  Zoom Previous

  Zoom to Span

  Editing the Time Span fields to pan the Time Span Viewer to selected regions of the timeline.

The Time Ruler covers the time span of the observations, indicated by the time span fields on the left and right side of the Time Ruler. When the time span is too large, Timeline automatically pans the display to show only the last day.

Timeline elements represent data collected over the duration of the survey. Because the Timeline and the Graphics window are also inter-linked together, data selected in this window is also selected in Time Span Viewer.

You can view a menu of commands by right-click on the Time Span Viewer background.


    Ephemeris Icons

More Information

How to ...	Dialog	See also
These icons identify the times where broadcast ephemerides were received by the receiver for individual satellites. Ephemeris information for each satellite tracked during a survey is recorded at the following times:

  At the start of the survey (if the satellite is visible)

  When the satellite first rises above the elevation mask

  Hourly

By default, the filter for these icons is turned off when Timeline first appears. You filter these icons by selecting commands from the Timeline toolbar or from several menus accessible in the Timeline viewing area. For more information, see Filtering Timeline Elements.

You can view the Satellite Ephemeris Properties dialog by double-clicking on a icon. This dialog includes useful information, including the satellite health status message. This message is useful for learning if the satellite contributing data to the observation was in poor or good health.

Right-clicking on a icon displays a menu of ephemeris-related commands.

Ephemeris icons cannot be deleted or disabled. Since Ephemeris icons are associated with a GPS observation, the GPS observation, or selected regions of the GPS observations, can be disabled to remove all associated ephemerides from the project data. For more information, see Disabling GPS Observations.


    GPS Observations

More Information

How to ...	Dialog	See also
GPS observation elements only appear in the Time Span Viewer when one or more data folders are opened to show the data collected during a survey session.

When a data folder is open, one Satellite icon appears for every satellite contributing GPS observations to the survey, and for each icon, GPS Observations represented by satellite tracking plots appear in the Time Span Viewer.

The shapes and color-coding scheme, shown below, are used in Timeline to distinguish different types of observation data from one another.

L1 P-Code   (Green)	L1 Phase   (Black)	Invalid Range	L1 Cycle    Slip	L1 C/A-Code       (Red)
L2 Full Phase (Black)	L2 P-Code   (Green)	L2 Cycle     Slip	L2 Encrypted       Code	L2 Half-Phase  (Thick Black)
When evaluating GPS observations, consider these guidelines:

  For single-frequency observations, satellite tracking information for the L1 carrier signal is represented as a sequence of pixels plotted across the Time Span Viewer.

  For dual-frequency observations, satellite tracking information for the L1 and L2 carrier signals is represented by two parallel sequences of pixels plotted across the Time Span Viewer.

  Long gaps between tracking plots represent periods when the receiver is not tracking the satellite. Small gaps between pixels represent cycle slips and other types carrier signal losses.

  Cycle slips, invalid range data, and other sources of spurious satellite signal conditions are also plotted within the strands of pixels.

Imagine each pixel in a satellite tracking plot to represent all of the raw data collected from one satellite at one instant in time. This raw data includes:

  Observation type − Phase, C/A-code, P-code, etc.

  Signal availability − True or false

  Signal status − Valid, invalid, cycle slip

  Enable/Disable status − Enable/disable flags

These pixels behave like switches with an on and off state. Disable a pixel and the raw satellite data associated with the pixel is also disabled. Enable a pixel, and the raw satellite data becomes available again. This allows you to use a trial-and-error approach while editing GPS observation data; you can disable selections of data and recompute a baseline to see if improvements in data quality result and re-enable the data if the results prove unsuccessful.

By selecting small areas of pixels (for example, regions of pixels containing cycle slips) those areas can be edited to improve the overall quality of GPS observations.

TIP: Selecting regions of pixels is performed by dragging a selection rectangle around the problematic data—simply place the mouse cursor over the upper-left corner of the area you want to disable, hold the left mouse button down, and drag a rectangle around the affected region.

To disable data for the selected region of pixels, double click in the selection rectangle to display the GPS observation properties dialog. Among other tools, this dialog includes options for disabling and enabling selected raw satellite data for individual satellites or selections of satellites. To learn more about selecting and editing Timeline elements, see Selecting and Editing Elements.

Several other tools are available when working with GPS Observation Properties dialog. These include:

  Disabling selected satellite data for multiple satellites

  Editing the starting and end times when satellite observation data was collected

  Editing individual Observation Types included in the GPS observation

From the control bar, you can disable a Satellite icon to remove all associated tracking information for a GPS observation from a survey. This is useful in cases where the overall health of all GPS observations associated with a satellite is poor and the satellite constellation for the occupation has sufficient redundancy to overcome the omission of the disabled satellite. For more information, see Disabling a Satellite.

TIP: You can learn the health of the GPS observations collected for a selected satellite by viewing the properties for the most recent Ephemeris icon appearing in the satellite tracking plots. These ephemeris updates are decoded by the receiver at approximately 1 hour intervals and include a message indicating the current health of each satellite. The URA and URA Flag fields are also useful for evaluating the overall quality of satellite broadcasts.

You can right-click anywhere within the GPS Observation element to view a menu of commands for working with GPS Observation data.

GPS observations cannot be deleted, but an entire GPS observation or selected regions of it can be disabled. Satellites can also be disabled to disable all associated GPS observation types plotted on the timeline.


    Occupation/Data Segment Elements

More Information

How to ...	Dialog	See also
Occupations and Data Segments represent a span of time where GPS observations are collected by a receiver. These can be classified into two types:

  Static Occupations, which include FastStatic and Stop and Go (Stop&Go) occupations. An Occupation represents a period of time where a receiver is stationary at a point.

  Continuous Segments, which include Roving Segments. A Continuous or Roving Segment represents a period of time where the receiver is moving while still collecting measurements.

Color Coding Scheme

Occupation and Data Segment spans are represented by color-coded rectangular regions showing the time span over which the occupation data was collected. These color codes and shapes are used to identify different types of information:

  Static and FastStatic occupations appear as large blue rectangular regions.

  Stop&Go occupations appear as small blue rectangular regions.

  Continuous Segments appear as large green rectangular elements.

  Roving Segments appear as small green rectangular elements.

  Segments with errors appear as red elements.

Satellite Constellation Plots

Two plots with information about the satellite constellation for the time of
the occupation or segment can be displayed when an occupation or
continuous segment is selected. For more information, see these topics:

  DOP Plot

  Skyplot

Dotted Lines

A dotted line represents areas where GPS measurements are available, but there are no Occupation or Segment elements associated with those measurements.

Roving segments are not imported into the database by default. They can only be created by converting a Continuous segment to a Roving segment. When the data are imported into TGO from a DAT file the Use checkbox for all Roving segments is clear.

If the checkbox is left clear, the Roving segment is not loaded into the project and the dotted line is used to indicate that there are GPS measurements available for this time period, but that there are no Occupation or Segment elements associated with those observations.

If the checkbox is selected, the Roving segment will be converted to Continuous, and a continuous segment will be displayed in Timeline. The only way to get a Roving segment is to change the Continuous segment to Roving.

Additional Guidelines

Consider these guidelines when working with occupations and data segments:

  All occupation and data segment properties can be viewed by double-clicking on the occupation or data segment.

  The time span can be adjusted directly by dragging the left and right edges of the rectangle.

  A Static Occupation may be changed to a Continuous or Roving Segment by selecting the appropriate type from the Occupation/Data Segment Properties dialog.

  Occupations and Segments can be deleted. Once deleted, however, they are no longer accessible from the project.

  The Next and Previous commands, also represented as blue arrow buttons on the toolbar, are used to pan the Time Span Viewer to the next or previous occupation or segment start or end point found in the active data folder.


     Satellite Icons

More Information

How to ...	Dialog	See also
Satellite icons represent the satellites contributing GPS measurements to the Survey. The satellite PRN number is printed on each icon for identification purposes.

Satellite Icons are hidden when Timeline first appears. To reveal the satellites, open one or more data folders in the control bar.

Minus sign shows folder is open
	Satellite icon
The satellite icons in the control bar have a one-to-one correspondence with the GPS Observations appearing in the Time Span Viewer the icon shows the satellite number and the GPS observations show the corresponding spans of satellite broadcast activity.

Right-click any of these icons to view a menu of commands. Use the Enable/Disable command to enable or disable the associated GPS observations appearing in the Time Span Viewer. This feature is useful for removing satellite information from an occupation. When disabled, the corresponding satellite tracking plots are color coded with light-tinted shading to denote their disabled state. Selecting the command a second time re-enables the tracking information. Use this command when the health of the satellite is in question. For instance, you might want to disable a selected satellite to determine if baseline processing results improve.

TIP: You can also disable selected regions of a GPS observation. For example, you can disable a region containing a cycle slip or invalid phase data. For more information, see GPS Observations.

Double-click on a Satellite icon to view the SV Plot window with commands for plotting the raw satellite tracking information collected from the satellite. SV Plot also offers an option for exporting the raw satellite data to a file in tabular format.

Satellite icons also can be rearranged within a data folder by dragging the icons to new locations in the folder. This is useful when selecting several satellites before editing GPS observation properties.


    Static Occupations

More Information

How to ...	Dialog	See also
Static occupations represent spans of time when the receiver remained stationary while collecting data at a point. The collected data identifies the exact location of the point and the time when the data was collected.

Static occupations appear as a large blue rectangle. The length of the rectangle represents the time span over which the data was collected. A Station Icon appears at the leading edge of the occupation, indicating the occupation was static.

Double-click on a Static occupation to view its properties. These properties show the segment and antenna information.

You can right-click anywhere within the Static Occupation element to view a menu of commands for working with Occupation data.

The Static Occupation element can be adjusted to change the time span. Static occupations may be changed to a Continuous or Roving Segment by selecting the appropriate type from the Occupation Type list in the Occupation/Data Segment Properties  dialog.

Because the Graphics window and Timeline are linked together, the occupations of points and baselines selected in the Graphics window are also selected in Timeline and vice versa. For example, you can select a Static occupation in Timeline to see its associated points and baseline selected in the Graphics window. Once the points or baseline are selected, you can view their properties to learn more about the occupation.

Two plots with information about the satellite constellation for the time of
the occupation or segment can be displayed when an occupation is selected. For more information, see these topics:

  DOP Plot

  Skyplot

TIP: The Properties window, accessed from the Graphics window, is also useful for navigating through Timeline to find selected occupations. The occupations of baselines and points selected from this dialog are also selected in Timeline. Once selected, you can double-click on the occupation element in Timeline to read its properties.

Occupation and Segment elements are displayed in color-coded rectangles for easy identification. For more information, see Occupation Color Coding Scheme.


     Survey Elements

More Information

How to ...	Dialog

Within the Time Span Viewer are one or more rectangular Survey elements. These Survey Elements are associated with a data folder which appears in the control bar. Each data folder represents a single receiver and contains information for one or more Surveys, which basically are files with GPS measurements.

The leading edge of a Survey element identifies the start time when the Survey session began and the trailing edge identifies the end time. When a single Survey element is contained within the data folder in the control bar, that Survey element spans the entire length of the timeline. Since numerous Surveys collected over several days could be included a project, a typical Survey element occupies only a small portion of the entire timeline.

You can double-click on the Survey element to view and edit its properties.

You can right-click anywhere within the Survey element to view a menu of commands for working with Survey data.

Survey elements can be deleted. Since Survey elements represent actual data, the associated data is also deleted from the project. Deleted survey elements appear in the Time Span Viewer as white rectangular regions surrounded by a black border. These regions let you know survey data once existed in this region of the timeline.


Timeline Elements - Overview
    Timeline Elements − Overview

More Information

How to ...	See also
Overview

Timeline uses graphic elements to represent the GPS survey data appearing the Time Span Viewer.

	Data Folder	Survey	Ephemeris icon
	Satellite icon	Occupation	GPS observation
These elements may be selected and their associated data properties can be edited. When appropriate, the time span of collected data can be edited, selected satellite tracking information can be disabled, and occupation or survey elements can be deleted. Actions performed on these elements affect their associated project data. These actions can improve survey data quality by removing problematic data affecting the overall quality of GPS observations.

Reading Element ToolTips

The following ToolTips appear when the mouse pointer is positioned over a Timeline element:

When the pointer is positioned over …	A ToolTip shows …
a survey element	the name of the data file associated with the element
an occupation or data segment element	the name of the station associated with the occupation
a GPS observation	the space vehicle number associated with the tracking information
an Ephemeris icon	space vehicle number associated with the ephemeris update
a satellite icon or data folder	the receiver model and serial number

For more information about these elements, see these topics:

  Surveys

  Occupations

  Station Icons

  GPS Observations

  Ephemeris Icons

  Event Icons


    Timeline Toolbars

More Information

 See also

Two toolbars appear when the Timeline view area appears—the Timeline toolbar and the Planning Plot toolbar. These two toolbars give you quick access to frequently used Timeline commands.

To learn more about the Timeline toolbars, see these topics:

  Timeline Toolbar

  Planning Plot Toolbar


Timeline View Area - Overview
    Timeline View Area − Overview

More Information

How to ...	See also
Overview

Timeline becomes available after importing one or more files with GPS measurements into your Trimble Geomatics Office software project. You must also be working in the Survey view.

To access Timeline:

1.	Open a project containing raw GPS data files.

2.	Do one of the following:

  Select View / Timeline.

  Press Alt+VI.

The Timeline view area appears at the base of the Graphics window.

The Timeline is divided into three viewing areas:

	Time Ruler
Control Bar	Time Span Viewer
These three areas are inter-linked together. The Time Ruler controls the amount of time-related survey information appearing in the Time Span Viewer, and the control bar controls the amount of raw satellite information appearing in the Time Span Viewer.

Think of the Time Span Viewer as a magnifying glass; it can view the entire timeline or zoom in on or pan to small spans of the timeline. Timeline offers several options for zooming and panning the information appearing in the Time Span Viewer. Because Timeline and the Graphics window are also inter-linked together, data selected in the Graphics window is also selected in Time Span Viewer.

Two other changes occur when Timeline is active: additional toolbars become available and the status bar displays Timeline information.

The Timeline View Area can be printed in portrait or landscape mode. For more information, see Printing the Timeline View Area.

To learn more about Timeline, see these topics:

  Toolbars

  Time Ruler

  Control Bar

  Time Span Viewer

  Timeline Elements


     Time Ruler

More Information

How to ...	Dialog	See also
The Time Ruler and Time Span Viewer are inter-linked together and work in unison; any change in time span is reflected in both windows.

Think of the Time Ruler and Time Span Viewer as a magnifying glass; you can zoom or pan selected areas of the timeline in the Time Span Viewer. The timeline might span several hours to several days of time and include many occupations. These two windows work together to view the entire timeline or small periods of it. Any change in one window is reflected in the other.

	Start Time Field	End Time Field
	Ruler
You can edit the End and Start Time fields or zoom the Time Span Viewer, depending on your immediate needs. Consider these actions:

  Edit the Start and End Time fields to zoom the Time Span Viewer when you need to examine the observation data for known periods of time. For example, you might want to zoom in on a period of time where high observation residuals caused a baseline solution to be rejected.

  Use the Zoom to Span command when you need to zoom in on a particular Timeline element. For example, you might want to expand a Continuous Kinematic Segment to fill the Time Span Viewer.

  Use the Zoom Extents command when you want to view the entire timeline in the Time Span Viewer. This is useful when several data files are included in the project and you need to relate the various time spans when the survey data was collected.

  Use the Zoom In command to scale the data in the Time Span Viewer in 200% increments. This command is useful when you want to zoom in on a small portion of a GPS observation to see gaps in satellite tracking broadcasts or cycle slips.

  Use the Zoom Out command to scale the data in the Time Span Viewer in 50% increments. Use this command when you need to see more of the GPS observation area. This is useful when trying to determine if a satellite can be disabled or not—you may need to know if there is sufficient redundancy in the satellite constellation to disable a satellite. Zooming out lets you see how many satellites were tracked during the time span.

  Use the Zoom Previous command to revert back to the previous magnification. This command is useful for returning to the previous zoom level after zooming in on or out from an occupation or GPS observation.

The Time Ruler can display two types of time units:

  Local Windows time

  GPS week/seconds

You can view the Time Options dialog to change units. Use local Windows time when it is easier to relate time spans to everyday time periods, such as the dates on a calendar or the time on your watch. Use GPS week/seconds when you need to correlate your time spans with GPS events or data. You can quickly switch between time units using a few mouse clicks.

Changes to time units are reflected in all Timeline properties dialogs and displays.

You can right-click the Time Ruler to see a menu of commands for working with the Time Ruler.

For more information, see these topics:

  Toolbars

  Control Bar

  Time Span Viewer

  Timeline Elements

  Timeline Properties dialogs

  Timeline Displays


     Station Icons

More Information

How to ...	See also
Use these small red triangular icons and labels to identify Static Occupations.

NOTE: Station Icons cannot be deleted or disabled—they are only deleted or disabled with their parent occupation.


     Event Icons

More Information

How to ...	See also
These icons identify both system-generated and manually-generated events that occur during survey data logging sessions. Event icons only appear in the Time Span Viewer and are presented as diamonds centered at the time the event occurred.

Event icons can be filtered to show or hide the icons by clicking [image] from the Timeline toolbar.


Timeline Menus - Overview
     Timeline Menus − Overview

More Information

Overview

Timeline menus can be used to quickly gain access to commands within the Timeline View Area. Each menu appears when a Timeline element or window is selected and the right mouse button is clicked.

These menus are available:

  Time Ruler

  Time Span Field

  Data folder

  GPS observations

  Time Span Viewer

  Survey

  Occupation

  Satellite icon

  Ephemeris icon


     Time Ruler Menu

More Information

 See also

Use this menu to quickly access Time Ruler commands:

To access it, do one of the following:

  Double on the Time Ruler background

  Right-click the Time Ruler back ground

A menu appears with these commands:

  Time Options

  Zoom Extents

  Zoom Previous


     Time Span Field Menu

More Information

 See also

Use this menu to quickly access Time Span Field commands.

To access it:

  Right-click the Start or End Time span field.

A menu appears with these commands:

  Undo

  Cut

  Copy

  Paste

  Delete

  Select All


     Control Bar Menu

More Information

 See also

Use this menu to quickly access control bar commands. The Timeline View area menus be visible to access this menu.

To access it:

  Right-click anywhere in the control bar.

The menu appears with these commands:

  Expand All

  Shrink All

  Zoom Extents

  Zoom Previous


     Satellite Icon Menu

More Information

 See also

Use this menu to quickly access Satellite Icon commands.

To access it:

  Right-click any Satellite icon.

A menu appears with these commands:

  Enable/Disable

  SV Plot


     Time Span Viewer Menu

More Information

 See also

Use this menu to quickly access Time Span Viewer commands.

To access it:

  Right-click the Time Span Viewer background.

A menu appears with these commands:

  View Filters

  Next

  Previous

  Zoom Extents

  Zoom Previous


     Survey Menu

More Information

 See also

Use this menu to quickly access Survey Interval commands.

To access it:

  Right-click a Survey element.

A menu appears with these commands:

  Delete

  Ephemeris Info

  Zoom to Span

  Zoom Extents

  Zoom Previous

  Properties


     Static Occupation Menu

More Information

 See also

Use this command to quickly access Static Occupation commands.

NOTE: The Static Occupation must be visible in the Time Span Viewer to access this menu. First, view Timeline, then open the data folder containing the occupation data.

To access it:

  Right-click a Static Occupation element.

The menu appears with these commands:

  Delete

  Ephemeris Info

  Zoom to Span

  Zoom Extents

  Zoom Previous

  Properties


     GPS Observation Menu

More Information

 See also

Use this menu to quickly access GPS Observation commands.

To access it:

  Right-click a GPS Observation element or a selection rectangle surrounding a region of a GPS Observation.

A menu appears with these commands:

  Enable/Disable

  Ephemeris Info

  Zoom to Span

  Zoom Extents

  Zoom Previous

  Properties


     Ephemeris Menu

More Information

 See also

Use this menu to quickly access commands for working with ephemeris information.

To access it:

1.	If necessary, open a data folder.

The folder is opened, revealing the Satellite icons.

2.	If necessary, turn on the Satellite filter.

The GPS Observations appear.

By default, the Satellite filter is turned on.

3.	If necessary, turn on the Ephemeris filter.

The Ephemeris icons appear.

4.	Right-click the desired Ephemeris icon.

The menu appears with these commands:

  Zoom to Span

  Zoom Extents

  Zoom Previous

  Properties


     Data Folders

More Information

How to ...	Dialog	See also
A Data Folder represents a single receiver. The type and serial number of the receiver which it represents are displayed on the folder. Survey projects will have two or more Data Folders, one for each receiver used in the project.

Each Data Folder contains information for one or more Surveys. A Survey corresponds to a single file with GPS measurements

Open and close data folders to show and hide the Satellite icons in the control bar and the associated GPS Observations in the Time Span Viewer.

Plus sign shows folder is closed
	Receiver model and serial number
Minus sign shows folder is open

	Satellite icon

You can open and close data folders in two ways:

  A plus sign (+) appears on the left side of the data folder when closed and a minus sign appears when it is open. You can click on the plus (+) and minus (-) symbols to open and close individual folders.

  The Expand All and Shrink All commands can be accessed in several ways to open or close all of the data folders in the control bar.

When opened, one Satellite icon appears for every satellite contributing GPS observations to the survey, and for each icon, GPS Observations represented by satellite tracking plots appear in the Time Span Viewer.

  For single-frequency observations, satellite tracking information for the L1 carrier signal is represented as a sequence of pixels plotted across the Time Span Viewer.

  For dual-frequency observations, satellite tracking information for the L1 and L2 carrier signals is represented by two parallel sequences of pixels plotted across the Time Span Viewer.

Receiver properties are displayed when you double-click on a data folder. Right-clicking a folder displays a menu of commands for working with the data in the folder.

Several actions can be performed on the Satellite icons and GPS observations revealed when a data folder is opened. For illustrations showing the various Timeline elements appearing in the control bar and Time Span Viewer, see Timeline Elements.


     Timeline Control Bar

More Information

How to ...	Dialog	See also
Use the control bar to manage the GPS observation information displayed in the Time Span Viewer.

The control bar is located in the lower-left corner of the Timeline view area. Actions performed in the control bar are reflected in the Time Span Viewer.

From the control bar, you can perform these actions:

  Open and close data folders

  Enable and disable Satellite icons and their corresponding GPS observations

  View Receiver Properties

  View an SV Plot to display the raw satellite tracking information broadcast by individual satellites

Use the control bar menu to access commands associated with the data currently viewed in Timeline. The Satellite Icon menu is useful for enabling and disabling the GPS observations associated with individual satellites. Also use it to launch the SV Plot display, with options for plotting the raw satellite tracking information for individual satellites.

For more information, see these topics:

  Toolbars

  Time Ruler

  Time Span Viewer


     Continuous Segment Menu

More Information

 See also

Open this menu to quickly access Continuous Segment commands.

NOTE: The Continuous Segment must be visible in the Time Span Viewer to access this menu. First, view Timeline, then open the data folder containing the continuous data.

To access it:

  Right-click the Continuous Segment.

A menu appears with these commands:

  Delete

  Ephemeris Info

  Zoom to Span

  Zoom Extents

  Zoom Previous

  Properties


     Timeline Toolbar

More Information

 See also

This toolbar appears in the toolbar area when Timeline appears.

This toolbar automatically appears when Timeline is started. You can hide the toolbar by selecting View / Toolbars / Timeline and show it again by repeating this command.

These buttons are available:

	Select this button to filter the red triangular-shaped Station icon and labels associated with occupations. Stations appear in the Time Span Viewer, at the leading edge or start point of a Occupation element. When you double-click on a Station icon, the occupation properties for the station appear with summary information about the station.
	Select this button to filter the diamond-shaped event icons appearing in the Time Span Viewer.
	Select this button to filter continuous segments. These segments are collected by roving receivers and have no initial associated station. Click the button once to hide the segments and once again when you want to show them.
	Select this button to filter the GPS observations collected by satellites. Click this button once to hide all GPS observations, and click it again when you want to show them again.
	Select this button to filter the ephemeris icons in the Time Span Viewer. Click the button once to make the icons visible and click it again when you want to hide them again.
	Select this button to open all closed data folders in the control bar. The Satellite icons and GPS observations for all satellites in the data folders are visible when you press this button.
	Select this button to close all open data folders in the control bar. The satellite icons and GPS observations for all satellites in every data folder are hidden when you press this button.
	Select this button to pan the Time Span Viewer to the previous Survey element. This button is only available when a data folder is selected. Each time you press this button, the previous Survey element is selected. This button is especially useful for quickly panning from Survey to Survey without using the scroll bars.
	Select this button to pan to the Time Span Viewer to the next Survey element. This button is only available when a data folder is selected. Each time you press this button, the next Survey element is selected. This button is especially useful for quickly panning from Survey to Survey without using the scroll bars.


     Planning Plot Toolbar

More Information

 See also

Use this toolbar to execute commands for viewing raw satellite and broadcast ephemeris information displays.

This toolbar automatically appears when Timeline is started. You can hide the toolbar by selecting View / Toolbars / Planning Plot and show it again by repeating this command.

These buttons are available:

	Select this button to view DOP Plot. This button is only available after selecting an occupation.
	Select this button to view the Skyplot for an occupation. This button is only available when selecting an occupation.
	Select this button to view the SV Plot for a selected satellite. This button is only available when a satellite icon is selected from a data folder.


     Time Span Editing Fields

More Information

How to ...	See also
Use the End and Start Time fields in the Time Ruler to pan the Time Span Viewer to a selected span of time.

Edit the Start and End Time fields to pan the Time Span Viewer when you need to examine the observation data for known periods of time. For example, you might want to pan to the span of time where a specific station is located on the timeline.

While editing these fields, you can right-click these fields to display a menu and use clipboard commands to cut, copy, paste, and undo text.


Satellite Constellation Plots - Overview
     Satellite Constellation Plots − Overview

More Information

How to ...	See also
Overview

Timeline can produce graphical displays with information about the satellite constellation. These displays are based on the ephemeris information that was current at the time of the occupation.

These include:

  DOP Plot

  Skyplot

These displays are only available when an Occupation element is selected. An occupation is required to obtain the coordinates of a point from which satellite visibility is computed.


     DOP Plot

More Information

How to ...	See also
Use this to display the number of satellites and Dilution of Precision (DOP), a measure of the expected quality of the GPS position based on satellite geometry, over the observation span. The information used to derive this display is based on ephemeris information that was current at the time of the occupation.

To view the DOP Plot for an occupation, do one of the following:

  Right-click the occupation in Timeline and select Ephemeris Info / DOP Plot.

  From the Planning Plots toolbar, click [image].

The DOP Plot is displayed.

DOP is a scalar measure of the quality of the satellite constellation geometry. Lower DOP values suggest stronger geometry and higher values suggest poorer geometry. Generally, the DOP is lower and the geometry is stronger when more satellites are in view. The Number of Satellites Plot shows the number of satellites in view with respect to the observation span.

The time of the day and your position affect DOP. Since periods of lower DOP and good satellite geometry are predictable using planning software, it is possible to schedule observations for those parts of the day when conditions are most favorable.

NOTE: The number of satellites and DOP calculations are based only on the ephemeris current at the time of the occupation. These displays do not necessary reflect actual tracking conditions, and as such may show more satellites than were actually tracked. This may be due to obstructions at the site, which are not accounted for when creating these displays.


     Skyplot

More Information

How to ...	See also
Use this display to view a local two-dimensional (horizon) plot of the satellite constellation visible from the selected location. The information used to derive the Skyplot is based on ephemeris information that was current at the time of the occupation.

To view the Skyplot display, do one of the following:

  Right-click an Occupation element in Timeline, and select Ephemeris Info / DOP Plot.

  From the Planning Plots toolbar, click [image].

The local horizon on the Skyplot is displayed in terms of azimuth and elevation.

Move the mouse cursor across the plot to view satellite tracking data in the status bar. The status bar identifies the satellite and shows the time, azimuth and elevation of the data point closest to the mouse cursor.

At the start of the occupation, the initial satellite constellation is highlighted with small squares around the data points. For this time point, the number of satellites and DOP are shown. You can update this data.

NOTE: The Skyplot is based only on the ephemeris current at the time of the occupation. This display does not necessary reflect actual tracking conditions, and as such may show more satellites than were actually tracked. This may be due to obstructions at the site, which are not accounted for when creating the Skyplot.


     Timeline Contents

Contents

The following Help Topics are available:

To learn how to use Timeline, read these topics:

  When and Why to use Timeline

  Timeline View Area

  Timeline Elements

  Timeline Data Properties dialogs

  Timeline Menus

  Timeline Commands

  Timeline Satellite and Ephemeris Displays

For Help on Help, Press F1.


Timeline - Overview
    Timeline − Overview

More Information

Dialog	See Also
Overview

Timeline displays GPS project information (such as the raw satellite and survey information collected by Trimble receivers or data collectors) in a graphical, time-based format. Each piece of information is represented with graphic elements at its appropriate position on a timeline. Timeline is available only in the Survey view.

To view it:

  Select View / Timeline.

Use Timeline to:

  view detailed plots for satellite observations

  disable selected satellite data

  selectively edit spurious GPS observation data

  edit the data properties associated with elements

  adjust the occupation times used in baseline processing

Once Timeline appears, you can select graphic elements and examine, verify, and edit the data associated with those elements.

For more information, read these topics:

  When and Why to use Timeline

  Timeline View Area

  Timeline Elements

  Timeline Data Properties dialogs

  Timeline Satellite and Ephemeris Displays


     When and Why to use Timeline

More Information

How to ...	Dialog	See Also
Use Timeline to examine, verify, and edit your GPS project information. You can use Timeline after transferring GPS raw data files to your Trimble Geomatics Office software project. If you want to inspect the GPS data collected in files before processing baselines, or edit antenna information, use Timeline to check the data. Timeline is most useful after baseline processing if the processing produced unexpected results. You can use Timeline to find problematic data and edit the data to improve its quality.

Use Timeline to examine GPS survey information for these conditions:

  Satellite signal cycle slips and other signal problems

  Poor satellite health

  Poor redundancy in satellite constellations

  Periods of poor DOP (Dilution of Precision)

  Antenna measurement problems

  Timing problems among multiple survey data files

Use Timeline to perform these trial-and-error tests:

  Adjust data collection time spans

  Disable and enable satellite tracking information

Use these Timeline actions to improve data quality:

  Adjust the occupation times

  Disable unhealthy satellites to improve overall observation residuals

  Selectively edit spurious GPS observation data

  Delete problematic occupations from baseline processing

  Delete problematic survey data files from baseline processing

Timeline maintains all the files with GPS measurements from a single receiver in a data folder. It also displays information about each GPS measurement file using Survey elements. Each receiver has its own, separate data folder, and all the Survey elements shown on a single row are from the same receiver.

Survey elements are shown for the time span over which the data was recorded. The data folders for each receiver can be opened to reveal additional information, thus representing all the data collected during the survey.

Use the mouse to navigate through the Time Span Viewer, then select elements to view or edit their data properties. Timeline satellite information and ephemeris displays can be used to view or edit the data in greater detail.

When using Timeline, you can still work in the Graphics window. These two views are inter-linked together—data selections and changes occurring in one viewing area are selected in the other. To learn how to use these two views together, see Selecting and Editing Timeline Elements.


     Selecting and Editing Timeline Elements

More Information

How to ...	Dialog	See also
Since the graphics window and Timeline are linked together, you can perform these actions:

  Select Timeline occupation elements and see the selected point selected in the Graphics window.

  Select a baseline in the graphics window and see the Occupation Segments making up the baseline highlighted in Timeline.

  Select a point in the graphics window and see the associated segments highlighted in Timeline.

NOTE: If the Dependent Baseline view is enabled, only observations that are shown in the Timeline view will be displayed in the graphics window. This is a useful tool for selecting independent baselines. To enable the Dependent Baseline view:

1.	Select View / Filters. The View Filters dialog appears.

2.	Select the Use Timeline to show dependent GPS baselines option and click OK.

Use the Planning Plot toolbar to display these detailed plots and graphs:

  DOP and number of SVs plots for a station occupation

  Skyplots of satellites for a station occupation

  Raw satellite tracking signal plots for a session

Use these plots and graphs to:

  Change the time span for the displayed data

  Open a number of displays at one time to view the information in various formats

  Resize and rearrange the windows to examine the data

  Print the plots and graphs

The plots and graphs are described in the following sections.

Element Selection

Five actions are associated with selecting Timeline elements or their corresponding project data:

  Single click an element to select the data associated with the element

  Double-click an element to view its information properties

  Right-click an element to view a menu of commands for working with the element

  Drag a selection rectangle around one or more elements before viewing their properties or disabling or deleting the data associated with the element

  Use Shift-click or Ctrl-click actions to select random selections of elements

Selecting an element is the same as selecting the project data associated with the element.

Undo Actions

The Trimble Geomatics Office software’s Undo command can be used to cancel some Timeline actions, such as deleting and disabling elements. When a Timeline element is disabled or deleted, its original element state is placed in the clipboard. Selecting the Undo command reverses the delete or disable action.

NOTE: The delete or disable action cannot be undone if another command overwrites the data in the clipboard.

The Undo command is also available when editing the Start and End Time field commands. You can cut or copy text from one field and paste it in the other.

Reading Element ToolTips

These ToolTips appear when the mouse pointer is positioned over a Timeline element:

When the pointer is positioned over …	A ToolTip shows …
a Survey element	the name of the data file associated with the element
an occupation or data segment element	the name of the station associated with the occupation
a GPS observation	the space vehicle number associated with the tracking information
an Ephemeris icon	the space vehicle number associated with the ephemeris update
a Satellite icon or data folder	the receiver model and serial number


     Editing Satellite Tracking Information

More Information

How to ...	Dialog	See also
Use the GPS Observation Properties dialog to edit a span of satellite observations and apply those edits to baseline processing. You can edit the various Observation Types in the satellite signal for one or more satellites. For example, you can disable the L2 Encrypted observation for one or several satellites.


Timeline Commands - Overview
     Timeline Commands − Overview

Overview

Various Timeline commands are executed using one or more of four methods:

  Double-clicking on Timeline regions and elements

  Right-clicking on Timeline regions and elements to display a menu and selecting one of the command options

  Clicking on toolbar buttons

  Pressing key sequences

Not all commands may support all four methods.

These commands are available:

  Continuous

  Copy

  Cut

  Delete

  DOP Plot

  Enable/Disable

  Ephemeris

  Ephemeris Info

  Events

  Expand All

  Paste

  Properties

  Satellites

  Select All

  Shrink All

  Skyplot

  SV Plot

  Timeline

  Time Options

  Undo

  View Filters

  Zoom In

  Zoom Out

  Zoom Extents

  Zoom Previous

  Zoom to Span

Additional commands are available in SV Plot.


Timeline Properties Dialogs - Overview
    Timeline Properties Dialogs − Overview

More Information

How to ...	Dialog	See also
Overview

Most survey data editing in Timeline is performed using the properties dialog. Some Timeline fields, however, such as the Start and End Time fields for Occupations and Segments, can be edited using the Time Ruler as well as from the properties dialog. Timeline commands for disabling and deleting data using the mouse also provide alternative ways of editing data.

Properties dialogs can be accessed in two ways:

  Double-click the element.

  Right-click the element and select Properties.

Timeline properties dialogs remain open until you click OK or Cancel. No changes in data are saved until you click OK. More than one properties dialog can be open at once, allowing you to compare various element properties. For example, you can view the properties dialogs for two or more occupations at the same time.

These properties dialogs are available:

  Receiver Properties

  Survey Properties

  Occupation/Data Segment Properties

  GPS Properties

  Ephemeris Properties

NOTE: Satellite icons do not have a properties dialog, but you can view SV Plot to plot, print, and export the raw tracking information collected for each satellite contributing data to the survey. These plots are useful for examining raw satellite tracking information when gaps in broadcast activity are discovered in GPS observations.


Timeline Displays - Overview
     Timeline Displays − Overview

More information

How to ...	See also
Overview

Timeline includes additional displays for viewing more detailed information about the satellite tracking and ephemeris information collected during a survey. These displays can be used as tools for further examining the data collected for occupations and the GPS observations collected for individual satellites.

These additional displays are available:

  Satellite Observation Display

  Ephemeris Information Displays

Guidelines for analyzing the information plotted in each of these displays are included in the topics above. Use these guidelines to perform a more thorough analysis of your data.


     Baseline Solutions

More Information

 See also

Five possible baseline solutions are described below:

  Float Solution

  Fixed Solution

  Widelane Fixed Solution

  Narrowlane Fixed Solution

  Ionospheric Free Solution


     Float Solution

More Information

 See also

A float solution is obtained when the baseline processor cannot compute a definitive integer value for the ambiguity terms. Often during the baseline processing, the ambiguity computes to a value such as 1000.60. This value is not close to an integer value, and it is difficult to determine whether the value should be set to 1000 or 1001. Therefore, the processor cannot set the value to the closest integer value. The baseline components are computed using the ambiguities as real values. This baseline solution is not as accurate as a fixed solution.

Float solutions result from unmodeled atmospheric, orbital, and other errors.


     Fixed Solution

More Information

 See also

A fixed solution is obtained when the processor is able to find a set of integer values for the ambiguity terms that is significantly better than all other possibilities. The baseline processor sets the ambiguity value to an integer number to compute the final baseline components. In real time surveying, there is an operational mode referred to as Fine, which indicates a fixed-integer solution.

For single-frequency receivers, the optimal solution is normally a double-difference fixed-integer solution. With dual-frequency receivers, it is possible to combine the carrier-phase observables in a number of ways, creating several different fixed solutions.


     Widelane Fixed Solution

More Information

 See also

Widelane refers to the process of using a combination of the L1 and L2 carrier-phase observables in the difference equations. Differencing the carrier-phase observables (L1−L2) creates the widelane carrier phase. The effective wavelength of the widelane is 86.2 centimeters.

It is easier to find the integer ambiguities using this measurement combination. Therefore, in many cases, the widelane is used when solving long baselines.


     Narrowlane Fixed Solution

More Information

 See also

Narrowlane refers to the process of using a combination of the L1  and L2 carrier-phase observables in the difference equations. Adding the carrier-phase observables (L1+L2) creates the narrowlane carrier phase. The effective wavelength of the narrowlane is 10.7 centimeters. The narrowlane is very effective in canceling out ionospheric effects on GPS survey observations.


     Ionospheric Free Solution

More Information

 See also

The ionospheric free solution uses a combination of L1 and L2 carrier phases to model and remove effects of the ionosphere on the GPS signals. This type of solution is often used for high-order control surveying, particularly when observing long baselines.


     Signal Strength

The signal strength of a satellite, also called the signal-to-noise ratio (SNR), is a measure of the information content of a signal to the signal’s noise. As this proportion decreases, information gets lost in the noise. Signal quality improves as the signal level increases (a signal level of 14 is better than a signal level of 8). The typical L1 signal level of a satellite at 30° is from 12 to 20. An L1 value above 20 is very good. The data quality is poor if the L1 signal level of one satellite in the constellation is below 6. Low signal levels give positions that are adequate for navigation but not for surveying. Be aware that L2 SNR is often lower than that of L1. You can focus on the L1 signal strength to assess data noise.

GPS satellite signals are relatively weak. In fact, in many cases the ever-present background noise is louder than the GPS signal. When the signal strength of a satellite is particularly weak, the positions calculated from those measurements tend to be inaccurate.

There are two common causes of weak signals. First, if the signal reaches the antenna after penetrating an obstacle such as tree canopy, it is usually weakened. The weakening effects of canopy can be minimized by setting up the receiver so that it has a clear view of the sky. Second, satellites which are low on the horizon usually have a weaker signal than those more directly overhead.

Use of low-elevation satellites can also result in multipath error (error resulting from a reflected GPS signal). To avoid the detrimental effects of low-elevation satellites, adhere to the recommended elevation masks for surveying. Most postprocessed surveys and real-time surveying are performed with a 13° mask. Satellite data is seldom logged when satellites are below 10°.


     Dilution of Precision (DOP)

Dilution of precision (DOP) is an indicator of the quality of a position. It is the result of a calculation that takes into account each satellite’s location relative to the other satellites in the constellation (the geometry) to predict the accuracy of positions obtained with that constellation. A low DOP indicates strong satellite geometry and a higher probability of accuracy. A high DOP indicates weak satellite geometry and a lower probability of accuracy.

The commonly calculated types of DOPs are listed below.

  Relative (RDOP) − relative position error

  Position (PDOP) − horizontal and vertical measurements (lat, lon, hgt)

  Horizontal (HDOP) − horizontal measurements (lat, lon)

  Vertical (VDOP) − vertical measurements (hgt)

  Time (TDOP) − clock offset

PDOP is the best overall indicator of constellation accuracy, although PDOP alone does not guarantee good baseline determination. A PDOP of 4 or below yields excellent positions. A PDOP between 5 and 7 is acceptable; a PDOP of 7 or more is poor. You can also set the PDOP mask on your receiver to ignore constellations that have a PDOP higher than the limit you specify. The default PDOP mask in the Trimble survey receivers is 7. Note that this mask only affects position determination and does not have as large effect on subsequent baseline processing.

The QuickPlan program allows you to calculate the PDOP during your field observations. By entering both the location and date of interest, the satellite visibility and geometry can be predicted.


Baseline Processing Log - Overview
     Baseline Processing Log − Overview

Overview

The baseline processor creates a log file with information that may be useful when analyzing baseline solutions.

The file is named ProcessingLog.html and is located in the Reports\Baseline folder that is found in each project. The file ProcessingLog.html can be viewed using an HTML viewer or web browser.

This file is created for each GPS processing session. If the previous file is not renamed, it is overwritten each time a new processing session begins. The baseline processor uses this file to log warnings and errors that affect the processing results.

If any warnings or errors are logged to this file during processing, a dialog appears when processing is complete to allow access to the contents of this file, based on the setting in the Project Properties / General tab for Error Reporting. One or more of the following error or warnings may be present in this file:

Errors

  Baseline not Solved

Baseline <FromPointName> -> <ToPointName> not solved

  Processing Segment has Insufficient Data for OTF Processing

Processing segment (<GPSWeek> <GPSWeekSeconds>) has insufficient data for OTF processing.  Segment length = <TimeDuration>

  Kinematic Segment Initialization Failed

Kinematic segment initialization failed.  Segment: <GPSWeek> <GPSWeekSeconds> -> <GPSWeek> <GPSWeekSeconds>

  Fixed Baseline Initialization Failed

Fixed baseline initialization failed

  Static Baseline Initialization Failed

Static baseline initialization failed

  Kinematic Solution Failed

<FileName> kinematic solution failed. Start: <GPSWeek> <GPSWeekSeconds>    Stop: <GPSWeek> <GPSWeekSeconds>

  Stop&Go Solution Failed

<PointName> Stop&Go solution failed.

Warnings

The following warnings may be encountered:

 Baseline has Duplicate Solutions

<BaselineId> Baseline has duplicate solutions in this session. Only one will be saved.

 Precise Ephemeris Unavailable

Precise ephemeris unavailable for <FromPointName> -> <ToPointName> <GPSWeek> <GPSWeekSeconds>, using broadcast


     Baseline not Solved

This ERROR has the following format:

Baseline <FromPointName> -> <ToPointName> not solved

<FromPoint> and <ToPoint> are point names from the project and can be used to identify the baseline.

When this error occurs an expected solution for this baseline will be missing from the GPS Processing list.


     Processing Segment has Insufficient Data for OTF Processing

This ERROR has the following format:

Processing segment (<GPSWeek> <GPSWeekSeconds>) has insufficient data for OTF processing. Segment length = <TimeDuration>

<GPSWeek> and <GPSWeekSeconds> are the time of the start of the segment for which the OTF processing failed. This time can be used to view the GPS measurements in question using Timeline.

<TimeDuration> is the amount of time spanned by the GPS measurements for which OTF processing failed.

When this error occurs the baseline processor was not able to perform an OTF initialization, which may cause one or more kinematic baseline solutions to fail. This may result in one or more expected baseline solutions missing from the GPS Processing list.


     Kinematic Segment Initialization Failed

This ERROR has the following format:

Kinematic segment initialization failed. Segment: <GPSWeek> <GPSWeekSeconds> -> <GPSWeek> <GPSWeekSeconds>

<GPSWeek> and <GPSWeekSeconds> are the time of the start and the end of the segment for which kinematic initialization failed. These times can be used to view the GPS measurements in question using Timeline.

When this error occurs the baseline processor was not able to perform a kinematic initialization, which may cause one or more kinematic baseline solutions to fail. This may result in one or more expected baseline solutions missing from the GPS Processing list.


     Fixed Baseline Initialization Failed

This ERROR has the following format:

Known point initialization failed

When this error occurs the baseline processor was not able to perform a kinematic initialization from a known point, which may cause one or more kinematic baseline solutions to fail. This may result in one or more expected baseline solutions missing from the GPS Processing list.


     Static Baseline Initialization Failed

This ERROR has the following format:

Static baseline initialization failed

When this error occurs the baseline processor was not able to perform a kinematic initialization from a static occupation, which may cause one or more kinematic baseline solutions to fail. This may result in one or more expected baseline solutions missing from the GPS Processing list.


     Kinematic Solution Failed

This ERROR has the following format:

<FileName> kinematic solution failed. Start: <GPSWeek> <GPSWeekSeconds>    Stop: <GPSWeek> <GPSWeekSeconds>

<FileName> is the name of the file with the GPS measurements used in the kinematic solution.

<GPSWeek> and <GPSWeekSeconds> are the time of the start and the end of the segment for which kinematic solution failed. These times can be used to view the GPS measurements in question using Timeline.

When this error occurs an expected solution for this baseline will be missing from the GPS Processing list.


     Stop&Go Solution Failed

This ERROR has the following format:

<PointName> Stop&Go solution failed.

<PointName> is the name of the point for which the Stop&Go kinematic solution failed.

When this error occurs an expected solution for this baseline will be missing from the GPS Processing list.


     Baseline has Duplicate Solutions

This WARNING has the following format:

<BaselineId> Baseline has duplicate solutions in this session. Only one will be saved.

<BaselineId> is the observation identifier used for this baseline in the project.

This warning occurs when a stop and go kinematic occupation is split by cycle slips. If each portion is two or more epochs, the baseline processor will generate solutions on each side of the slip as if there were two occupations of this point.

If the Overwrite Duplicate Baseline Solutions check box is selected only one of the solutions will be saved. By default, the last solution will be saved. This can be changed, however, by selecting the check box of the baseline solution you want to keep, and clearing the check box of the one you do not want to save.

Duplicate baseline solutions can be identified by the baseline ID, which will be the same for both solutions.


     Precise Ephemeris Unavailable

This WARNING has the following format:

Precise ephemeris unavailable for <FromPointName> -> <ToPointName> <GPSWeek> <GPSWeekSeconds>, using broadcast

<FromPoint> and <ToPoint> will be replaced with actual point names from the project and can be used to identify the baseline.

<GPSWeek> and <GPSWeekSeconds> are replaced by the time of the start of the baseline for which precise ephemeris is not available. Check the project folder that contains the precise ephemeris files to ensure adequate coverage.

This warning indicates that precise ephemeris processing was requested, but insufficient precise ephemeris data were available. When this occurs the broadcast ephemeris is used instead.