Description of the Dedicated Gravitational Satellite Mission (GRAVSAT)

A description of the dedicated gravitational satellite (GRAVSAT) mission is presented. Scientific objectives are to substantially improve our knowledge of solid earth geophysics and oceanography by determining a more accurate geopotential. The most stringent requirement is determination of mean gravity anomalies over regions- 100-km square to an accuracy of 2.5 mgal (1 gal = 1 cm/s2). Fundamental geodetic data will be satellite-to-satellite measurement of relative range rate. Orbital characteristics are discussed. An error budget is presented which indicates that the requisite measurement precision can be achieved by closed-loop RF doppler measurements. Implicit in the discussion of the error budget is a description of the spacecraft and systems components.