A projection is used to transform local geodetic coordinates into local grid coordinates. GNSS RTK measurements (both single base and VRS) are referenced to the Global reference datum defined for the job.. To work in local grid coordinates during a GNSS survey, you must specify a projection and datum transformation.

You can specify a projection:

  • when a job is created and you have to choose a coordinate system (select from a list, or key in)
  • during a survey (you calculate values by performing a calibration)
  • in the Trimble Business Center software, when the data is transferred.

Enter an appropriate default height value for the software to correctly calculate a sea level correction and then apply it to the grid coordinate.

If a projection and datum transformation are specified, you can reduce any discrepancies between the Global coordinates and the local grid coordinates by performing a site calibration.