Geo 7x with TerraSync

1. If you are using data dictionaries, way points, or basemaps in your field work, transfer the files to the Geo 7x handheld following the instruction in the “Transferring Files” section on this page.
   
   
2. If you will post-process your data, identify the base station you will use. You can use the CORS map to find the closest base station and if the station supports systems other than the US GPS.  These information are required for the handheld to display the approximate accuracy of the positions to be collected, see section “Setting Accuracy Display“.

   For high-accuracy position collections, the base station should not be more than 20km away from your field, and under 10km is desired.

   As an example, you can find the closest base station on the CORS Map page by entering a place name or an address. Click the base station on the map to see if it supports systems other than the GPS.
   

3. If you plan to use a real-time correction service that requires wifi or cellular service , make sure the communication service will be available at your field work site.
   
   
4. Check if the battery of the handheld needs to be charged.
   
   
5. If the handheld has been kept indoor for longer than two weeks or so, or has been transported for a long distance since it was last used, leave the receiver on under open sky for the receiver to get updated almanac. This will shorten the Time to First Fix in the field.
   
   
6. If you are using the external antenna, learn how to connect the antenna with the range pole and the handheld. See section “Connecting the External Antenna“.
   
   
7. Configure the handheld for your field work needs. See the other sections on this page for details.

In the “Start” window, tap the “TerraSync” application. 

Or, tap the “TerraSync” button if it is already on the screen.
 

1.  In the “TerraSync” window, tap the top drop-down arrow and tap “Setup“.
   
   
   
2. Tap the “Coordinate System” button.
   
   
   
3. Select the coordinate system and datum you want to use.

   
   If you want to collect height, you may choose the “Mean Sea Level (MSL)” option in the “Altitude Reference” box and load a local geoid model to the handheld. The built-in “DMA 10×10 (Global)” model is not very accurate. See section “Loading Local Geoid Model” for more details. Antenna height also needs to be entered for accurate height measurement.

   For field work in Minnesota, you can use
   

4. Tap the “Done” button at the bottom.

It helps to know in the field the approximate accuracies of the positions to be collected. For example, if the accuracy is below your minimum requirement and is deteriorating, you may want to stop collecting until the accuracy improves.

1. In the “TerraSync” window, tap the top drop-down arrow and tap “Setup“.
   
   
   
2. Tap the “Logging Settings” button.
   
   
   
3. Tap the setup button for “Accuracy Settings”. 
   

4. For each position type (horizontal or vertical), tap the the type of accuracy you’d like the handheld to display. If you will post-process the data, select “Postprocessed“; otherwise select “In the field” (your data will get corrected real-time using a satellite-based augmentation system or a real-time correction service).

   If you selected “Postprocessed“, enter the approximate distance between your field site and the base station (base distance) and if the station supports system other than the US GPS (see section “Before Field Work“). For example:

   

5. If you want to exclude positions that do not meet your minimum accuracy requirement, select “Yes” in the box “Use Accuracy-based Logging” and enter your required minimum accuracy. For example:
   
6. Tap the “Done” button at the bottom.

If you use a real-time correction service, it is important that you correctly specify the datum used by the correction source. Positions calculated by the Trimble handheld reference the WGS 1984 datum. When real-time correction source references a different datum, TerraSync transforms incoming positions to the datum used by the correction source and back to the WGS 1984 datum after positions are corrected. Incorrect entry of the correction source datum will lead to errors in the output corrected positions.

You should get service setup information from your service provider. The instructions here are written for the correction service provided by the State of Minnesota (https://www.dot.state.mn.us/surveying/cors/). The Geo 7x handhelds at Carleton/St. Olaf are all set up with this service.

1. In the “TerraSync” window, tap the top drop-down arrow and tap “Setup“.
   
   
   
2. Tap the “Rea-time Settings” button.
   
   
   
3. Tap the “Choice 1:” drop-down arrow and select the type of the correction service. For the service provided by MN State tap “External Source“.
   
   
   
4. Tap the setup button to enter information for the service.
   
   
   

   The settings displayed below are for the correction service provided by the State of Minnesota as of April 2022. The correction datum is the datum referenced by the mount point you choose after clicking the wrench button next to “Source“. Internet connection is needed to fetch the mount points list from the server. 
   
   
   For high accuracy position collection, it is important that you choose the more modern CMRx mount point.

Under construction

Under construction