Effect of Topography on Airborne Gravity Gradiometer Data

摘要

The reduction and conversion of airborne gravity gradiometer data to ground level estimates of the gravity disturbance vector is currently of considerable interest in support of short wavelength gravity modeling. A pressing problem is the need for an accurate procedure for the downward continuation of data acquired at altitude by the Airborne Gravity Gradiometer Survey System (GGSS). As part of ongoing investigations, a prism method has been used to calculate the effect of topography on the gravity disturbance vector and the five independent second order gravity gradients. Calculations of the contribution of topography to the magnitudes of these gravimetric parameters were made at both surface and elevated points in the Wichita Mountains of Oklahoma. Computations were made utilizing Digital Terrain Elevation Data (DTED) with an assumed constant density of 2.67 grams/cc for the topographic masses. Results are presented which reflect the use of DTED sets of different horizontal extend and grid interval.