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TBC Does That: Convert Coordinates from Grid to Ground for Survey Workflows

What TBC does

Surveyors measure land surfaces using a ground coordinate system, and TBC displays survey data in grid coordinates. In case you prefer to work in TBC with ground coordinates, TBC can convert grid to ground with the click of a button.

How does this help

Measurements using ground and grid coordinates are different. A grid distance shows the measurement between two points at a designated grid plane, while a ground distance reflects your position relative to the origin of the grid plane from the actual point on the surface of the Earth (i.e., the summit of a 14,000-foot peak), so elevation and your position relative to the origin of the grid plane are both factors. In some situations, perhaps if you are calculating lengths of wire or pipe needed for a project, you may want to work in TBC with ground coordinates so the numbers match your original field measurements. Also, it helps when you plan to use the ground measurements in other 3rd-party applications. 

How it works

TBC can convert ground to grid or grid to ground.

To convert from grid to ground:

  • Go to the Survey tab and click the Local Site Settings command
  • Enter an estimated centroid position for your project
  • Check the box for "Use ground coordinates" 
  • Allow TBC to "Compute ground scale factor from the project location"
  • Click OK

Now your measurements are in ground distance!

For more details about converting grid to ground coordinates, watch this TBC Power Hour webinar recording: Defining and Working with Grid and Ground Coordinates.


The “TBC Does That” series, written by the Trimble Business Center (TBC) Team, focuses on the broad range of functionality that TBC delivers to you. Periodically we will release information to help you improve productivity by making the most of TBC’s built-in tools.