Change the Coordinate System

Choose the appropriate coordinate system (also referred to as a coordinate reference system) for your project by selecting one that you have recently used or by defining parameters for a new one.

To change the coordinate system for your project:

1. Do one of the following:
   • Select Coordinate System in Photogrammetry > Setup or in Mobile Mapping > Processing.
   • In the Project Settings dialog, select Coordinate System in the left pane and then click the Change button.

     Note: A button on the Trimble Business Center Task Bar identifies the current type of coordinate system configured for the project: "Grid," "Ground," or "Calibrated." You can click this button to display the Coordinate System settings in the Project Settings dialog and make changes if necessary.

2. In the Change Coordinate System dialog, select the appropriate option (if displayed) for changing the coordinate system used in your project.
   • Search by name, country, or EPSG ID - Search for the coordinate system you want to use by entering the system's name, country, or EPSG ID.
   • Coordinate System and Zone – Select the coordinate system group, zone, and vertical datum to define a new coordinate system.
   • Calibrated Site - Select an existing calibrated site (if available) to use for the coordinate system.
   • Default projection (Transverse Mercator) - Select projection parameters and, optionally, a predefined geoid model datum to use for a new coordinate system.
   • Recently used coordinate system - Select from up to 10 of the most recent coordinate systems used in Trimble Business Center.

   See the appropriate section below for additional instructions.

   Note on using a coordinate system based on a different global reference datum or epoch...

   When you select to re-compute project coordinates using a coordinate system based on a different global reference datum or epoch, TBC displays a dialog that allows you select whether to keep the global coordinates unchanged (for example, if the global reference datum was incorrect) or transform the global coordinates from the old datum and epoch to the new datum and epoch. This will allow:

   • Interactive time-dependent transformation in TBC
   • The correct conversion of a project to a modernized datum (like conversion from GDA94 to GDA2020 in Australia)
   • The ability to fix a job logged using "Unknown" (“WGS84”) or the wrong global reference frame

Search by name, country, or EPSG ID option:

1. In the Search field, enter the name, country, or EPSG ID for the coordinate system you want to use.

   The search results list is filtered and updated immediately as you type..

2. In the filtered search results list, select the coordinate system you want to use.
3. Click Finish.

Coordinate System and Zone option:

1. Select the appropriate coordinate system group and zone.
2. Click Next.
3. Specify whether to use a predefined geoid model for your vertical datum. If you specify to use a predefined geoid model, select the appropriate model and its quality.
4. Optionally, enter a name for the new vertical datum.
5. Click Finish.

Calibrated Site option:

1. Select the calibrated site you want to use.
2. Click Finish.

Default projection (Transverse Mercator) option:

1. If you are working with a new project into which coordinate data has not yet been imported, optionally check the Automatically calculate projection parameters check box. Then, optionally, specify the false northing/easting and scale factor to apply when coordinate data is imported. Or, keep the false northing/easting default setting of 0,0, in which case the false northing/easting will be automatically selected when coordinate data is imported.

   Note: The Automatically calculate projection parameters option is intended for use only in a new project into which coordinate data has not yet been imported. When there is existing coordinate data in the project, the check box is unchecked by default and should not be checked. In this case, the current projection origin will be used in the new system with the false northing/easting set to 0,0.

2. Specify whether to use a south azimuth system.
3. Specify the North/South and East/West positive coordinate direction.
4. Click Next.
5. Specify whether to use a predefined geoid model for your vertical datum.

   If you select the Predefined geoid model option , select the appropriate model and its quality. Optionally, enter a name for the vertical datum.

6. Click Finish.

Recently used coordinate system option:

1. Select the coordinate system you want to use in your project.
2. Click Finish.

Related topics

Coordinate System Manager

Coordinate System Settings