Geopotential Determination From Satellite To Satellite Tracking And Satellite Altimetry

This report is a supplement to a report entitled 3Geopotential Determination From Satellite To Satellite Tracking and Satellite Altimetry3, ETL-CR-74-21, February, 1975. Under appropriate circumstances (as reported in the final report) it has been found that when conservation of energy principles are used in determination of spherical harmonic coefficients of the earth's gravity field, a diagonal set of normal equations is generated. Test results are presented which indicate that perturbations due to extraterrestrial and nonconservative forces may be isolated so that these forces will not contaminate the conservation of energy solution. Uncertainties in gravitational anomalies and deflections of the vertical as a function of uncertainties in the determined spherical harmonic coefficients are given. These uncertainties are given when the spherical harmonic coefficients are determined from conservation of energy principles and from conservation of energy principles augmented with satellite altimetry. In the latter case a reduction by a factor of about thirty in the surface gravity standard deviation is realized when satellite to satellite tracking is augmented with satellite altimetry.

A study has been made to determine the accuracy with which geopotential may be recovered using the principle of conservation of energy. The improvement resulting from the use of altimeter measurements over selected oceans areas was also investigated. Satellite position and velocity were determined by using range and range rate measurements for a system (621B) of high orbiting satellites whose own positions and velocities had previously been determined by ranging from known ground stations.

This volume covers a broad range of altimetry applications, including marine gravity and geoid, sea level change, ocean tide modeling, ocean circulations, marine plate tectonics, mesoscale eddies and bathymetry predictions. Virtually all disciplines of earth sciences are touched upon through the technique of satellite altimetry. Readers will find useful data processing techniques and novel applications of satellite altimetry, which otherwise are scattered in journals and special books.