A Comparison of Techniques for the Integration of Satellite Altimeter and Surface Gravity Data for Geoid Determination

Abstract

Two methods are tested whereby satellite altimeter measurements of the geoid height are combined with surface measurements of the free-air gravity anomaly. The study area comprises the oceans around the Australian continent. The first method involves draping a grid of the free-air anomaly from satellite data onto a grid of the ship and land data. The second method utilises grids of the altimeter-derived geoid height, combining these with the surface data in an iterative superposition. Preliminary results show that the draping method yields a fit of 5.4 mGal between the satellite and marine data, while the iterative procedure returns 8.1 mGal. Further work can be done, however, to improve these results. The impact of the combined marine gravity data sets is illustrated by comparing the effects on an Australia-wide spherical-FFT geoid solution.