# Coordinate systems in Tunnels

The Tunnels software treats all tunnel distances, including station and offset values, as grid distances. The value in the Distances field in the Cogo settings screen has no effect on the tunnel definition or the way tunnel distances are displayed. To view the Cogo settings screen, tap and select Settings / Units Cogo / Cogo Settings).

If a ground coordinate system is defined in the job, the grid coordinates are, in effect, also ground coordinates.