Impact of Satellite Altimetry on Geodetic Datum Definition

Based on results of the geodetic calibration and analysis of Skylab altimeter data, the concept of determination of the geoid in the oceans — the marine geoid — from satellite altimetry has been demonstrated. In principle, the satellite altimetry geoid should combine and improve on all the strong features of the gravimetric, astrogeodetic and satellite-derived geopotential coefficient geoids in terms of scale, shape, and absolute orientation. The criteria for achieving these conditions have been discussed with supporting investigations in other publications by the authors. It is shown that the satellite-altimetry-derived marine geoid, which could cover about 70 per cent of the world, can be used for 1) modification of scale, shape, orientation, and centering of the various geoids in each continent to achieve uniformity and compatibility that currently do not exist, and 2) improved intercontinental ties between computed geoids and geodetic datums of the various continents. Achievement of these objectives will contribute to a better definition of the figure of the earth and geodetic datums required for adjustment of geodetic networks.