# Project height

The project height can be defined as part of the coordinate system definition when creating a new job. To edit the project height:

1. Tap and select Job.
2. Tap Properties.
3. Tap Coord Sys.
4. Select the Select from library or Key in parameters option. Tap Next.
5. Enter the Project height.

To automatically complete the Project height field when defining or editing the coordinate system, tap Here to use the current autonomous height derived by the GNSS receiver, or tap Point to use the height of a point in the job or in a linked file. The Point softkey is not available when you are creating a new job. The Here softkey is available only when the software is connected to a GNSS receiver.

If a point has no elevation, the Trimble Access software uses the project height in Cogo calculations. If you combine GNSS and 2D conventional observations, set the Project height field to approximate the height of the site. This height is used with 2D points to calculate grid and ellipsoid distances from measured ground distances.

In 2D surveys where a projection has been defined, enter a value for the project height that approximates the height of the site. You need this value to reduce measured ground distances to ellipsoid distance, and to compute coordinates.

When the ground coordinate system scale factor is being computed based on the project location, any changes to the project location will change the ground scale factor, and this in turn will mean that any GNSS calibration based on this will need to be recomputed.