Trimble Access – Selecting Satellite Set

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In Trimble Access version 2020 or higher, a feature was added to allow the user In RTK surveys, to measure points with independent subsets of the currently tracked GNSS satellite constellation. This allows for consecutive measurements to be independent of each other, without having to revisit the point after a significant period of time to ensure the constellation has changed. The SV subset function divides all tracked SVs into two subsets with an even spread throughout the sky and can be used to make an occupation independent without having to return at another time. The SV subset function is available from the Satellites screen or the RTK Initialization screen.

We recommend people build redundancy and independent checks into GNSS measurements when measuring important GNSS points. Typically, that means measuring the point then either moving the rod off the point, breaking initialization, initializing away from the point to be collected and using the Observed control point method to insure there is enough time and enough epochs to check the initialization. Another method is to measure the point then come back in a different satellite constellation, wait at least 30 minutes, and measure the point again. This new feature does both of these methods and more to speed up measurement windows and build in independent checks.

Procedure

Users can select the SV subset from the Satellite screen or the RTK initialization screen. To open the Satellite screen, tap on the satellite icon (shown with the number of satellites available) on the top status bar.

Trimble Access 2020 Satellite Screen Icon

After opening, you have the option of a List or sky Plot view, shown in the bottom right.

Trimble Access 2020 Satellite Screen

Use a softkey at the bottom of the screen to change to the SV set A.

  • Tap the screen softkey
  • Use the keyboard only, press Ctrl button then the corresponding keyboard number of the desired softkey

If you see SV set A, tapping it will activate that subset.

The softkeys work as a toggle with three choices: SV set A, SV set B and All. The softkey does not reflect the currently active mode, it shows what subset it will change to.

The Satellite # on the Status bar show what is currently active satellite set selection.

Trimble Access 2020 Active Satellites

Reset Initialization or Satellite subset

Another way to select or reset the Satellite subset is to use the RTK initialization screen
In a survey, tap Menu → Measure → RTK Initialization

Trimble Access 2020 RTK Initialization Screen Trimble Access 2020 RTK Initialization Methods

Change the Method to the Subset you want to use then tap Reset. This will change the tracked subset, reset the current initialization and start the new initialization.

Note: If you do not see a selection list in the method, there is a measurement active on another screen. Close any active measurements to use this feature.

Adding the switch to a Data Collector Function Key

Use the Favorites Edit to add the Select satellite subset to a Function key for fast changes.

Tap Menu → pencil to edit the current group

Trimble Access 2020 Menu Group Selector

Toggle to edit the Function keys

Trimble Access 2020 toggle to edit the function keys

Tap the # key to assign

Trimble Access 2020 List of Function Keys on the edit screen

From the survey actions, select a command to preform for that function key.

Trimble Access 2020 Dropdown list of available Function Key Commands     Trimble Access 2020 Function Key list showing a saved command

Now, unless you are actively in a measurement, tapping the assigned function will toggle between ALL, SV set A, and SV set B.


View the original Survey Technical Support Notes: Trimble Access – Selecting Satellite Set

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Seiler Geospatial
Leading the geospatial industry since 1945, Seiler Geospatial provides top-tier hardware and software solutions. We are Authorized Distributors for Trimble Navigation, Spectra Precision, Esri, Autodesk, DJI, Laser Technology and more. We have nationally recognized service and repair facilities and offer certified training and support across the Midwest.  Our headquarters operates out of St. Louis and we have seven other offices across the Midwest.  Seiler’s team members are all skilled professionals that believe in a hands-on approach to working with our customers.  Our team members include Registered Land Surveyors, Certified GISP Professionals, Licensed Pilots, Certified Trainers as well as other surveying, mapping, LiDAR Specialists and many other skilled professionals and support staff.