Efficient terrain correction in airborne and seaborne gravity gradiometry surveys

Abstract

Proper terrain correction in airborne and seaborne gravity gradiometry surveys requires detailed digital elevation models (DEMs). However, due to standard low-pass filter techniques applied during acquisition, the required resolution of the DEMs is altered in commercial surveys. We quantify the ideal resolution for an example dataset with a new and practical method for performing terrain corrections based on Parker's 1972 Fourier domain calculation. In the same vein, we quantify the required spatial extents of DEMs for nominal cases. With these parameters quantified, we can optimize the terrain correction to improve efficiency in both gravity gradiometry forward modeling as well as terrain corrections. In an ideal case, we find that the required spatial extent of the DEM is roughly nine times the greatest relief in the terrain outside the survey area. For the specific case, we find that 20 meter resolution is suitable.