How far out from a station can INNERTC be used for terrain corrections?
In principle, there is no limit to how far out INNERTC can be used. Typically, though, INNERTC is used to a distance of 3-5 km from a gravity station. Terrain at greater distance is corrected using a terrain correction program designed for distant terrain; such programs typically use terrain data having spatial resolutions much coaser than the 30-m DEM data that is commonly used by INNERTC. However, there are users who regularly use INNERTC to correct for terrain as far as 20 km from gravity stations.
