Import topography
Navigate to the Horizons bar:

press Load external topography button
In the appeared preview file dialog chose file, set the loading parameters:
- File type
- Headers row
- X,Y,Z columns and scale ratio

Check the loaded parameters in Pre-load view tab and press Open:

For more information about external topography formats supported by g-Space refer to Grid Data Formats
Downloading topography from the web
If you do not have a topography file, g-Space can download a digital elevation model (DEM) for the project area from an online elevation service. The downloaded DEM is stored as a georeferenced topography surface and can be used in processes that need elevation (for example velocity model creation). You can also download satellite basemap imagery for the same area - see Import satellite imagery.