Gravity terrain corrections calculated using digital elevation models

Abstract

Abstract Corrections for terrain effects are required for virtually all gravity measurements acquired in mountainous areas, as well as for high-precision surveys, even in areas of low relief. Terrain corrections are normally divided into two parts, one part being the correction for terrain relatively close to the gravity station (the "inner-zone" correction) and the other part being the correction for more distant, say, >2 km, terrain. The latter correction is normally calculated using a machine procedure that accesses a digital-terrain data set. The corrections for terrain very close to the gravity station are done manually using Hammer's (1939) procedures or a similar method, are guessed in the field, or simply are neglected. Occasionally, special correction procedures are used for the inner-zone terrain corrections (e.g., LaFehr et al., 1988); but such instances are uncommon.