Analysis of SatellitetoSatellite Tracking (SST) and altimetry data from GEOSC
Abstract
Radar altimetry and satellitetosatellite (SST) range and range rate tracking measurements were used to infer the exterior gravitational field of the earth and the structure of the geoid from GEOSC metric data. Under the SST analysis, a direct pointbypoint estimate of gravity disturbance by means of a recursive filter with backward smoothing was attempted but had to be forsaken because of poor convergence. The adopted representation consists of a more or less uniform grid of discrete masses at a depth of approximately 400 km from the earth's surface. The layer is superimposed on a spherical harmonics model. The procedure for smoothing the altimetry and inferring the finestructured gravity field over the Atlantic test area is described. The local disturbances are represented by means of a density layer. The altimeter height biases were first estimated by a least squares adjustment at orbital crossover points. After taking out the bias, long wavelength contributions from GEM6 as well as a calibration correction were subtracted. The residual heights were then represented by a mass distribution beneath the earth's surface.
 Publication:

NASA STI/Recon Technical Report N
 Pub Date:
 April 1978
 Bibcode:
 1978STIN...7822133W
 Keywords:

 Data Reduction;
 Geos 3 Satellite;
 Radio Altimeters;
 Range And Range Rate Tracking;
 Satellite Tracking;
 Ats;
 Computer Programs;
 Data Smoothing;
 Geoids;
 Gravitational Fields;
 Recursive Functions;
 Spherical Harmonics;
 Astrodynamics