How To Set Up Elevation

Elevation is needed for sensor models that do earth intersects at height above the ellipsoid. This is derived from two parts, the geoid grid (vertical datum), and the height above mean sea level which usually comes from elevation cells, sometimes referred to as a digital elevation model(DEM). Elevation cells are relative to a given vertical datum. At runtime the ossimElevManager will supply sensor models with the height above ellipsoid which is "geoid_grid_point + elevation_cell_post. This happens automatically provided you have set up you ossim_preferences file correctly and have the appropriate data in you elevation repositories.

1) Set up the geoid grids