Precision gravity detection - Gradiometry and/or radiometry

Abstract

Current knowledge concerning the earth's gravity field is limited to about 1500-2000 km resolution. However, the resolution of gravity anomalies having a spatial extent of 100-1000 km over the entire globe is needed for important geophysical and geodetic applications. In the near future satellite altimetry will be used to determine the ocean geoid at the 10 cm - 1 m level. In order to provide a similar level of resolutions over the land regions, there exists a need for utilizing new promising techniques such as gravity gradiometry and new radiometric measurements, viz., satellite-to-satellite tracking. Satellite-to-satellite tracking techniques have shown potential for improving the medium wavelength component of the gravity field. The gravity gradiometer has not yet been tested on board a satellite. The reported analysis includes a simplified theoretical model to compare the effectiveness of the gradiometer measurements and radiometric measurements for high resolution gravity field determination, and the direct estimation of local gravity anomalies represented by point masses using a simulated gravity gradiometer and satellite-to-satellite tracking data.