Accession Number : AD0726122

Title :   The Determination of Gravitational Potential from the Measurement of Relative Velocity between Satellites.

Descriptive Note : Doctoral thesis,

Corporate Author : MASSACHUSETTS INST OF TECH CAMBRIDGE CHARLES STARK DRAPER LAB

Personal Author(s) : Comfort,Gary Christopher

Report Date : JUN 1971

Pagination or Media Count : 156

Abstract : The detailed characteristics of the gravitational potential of the earth are not generally known due to the difficulty of making continuous global measurements. The continuous on-board measurement of relative velocity between two satellites in the same nominally circular polar orbit but separated by a small central angle is investigated. It is shown that this measurement of relative velocity along the line of sight between the co-orbiting satellites directly measures the difference in kinetic energies between the satellites. The short period components of this measurement can be interpreted as a direct measure of the short wavelength portion of the disturbing potential encountered along the nominal orbit. This allows the direct mapping of the short wavelength anomalies in the potential encountered along the nominal orbit of the satellite pair. In addition, the representation of this short wavelength portion of the potential in terms of a spherical harmonic model is considered. A method is developed to accurately recover the zonal harmonic coefficients of degree greater than ten in that expression for the earth's potential. The difficulties in recovering tesseral harmonic coefficients are discussed. The actual implementation of the satellite pair measurement scheme is investigated and found to be feasible. (Author)

Descriptors :   (*GRAVITY, MEASUREMENT), POTENTIAL THEORY, SYNCHRONOUS SATELLITES, POLAR ORBIT TRAJECTORIES, MATHEMATICAL MODELS, PERTURBATION THEORY, SPECIAL FUNCTIONS(MATHEMATICAL), HARMONIC ANALYSIS, EQUATIONS OF MOTION, THESES

Subject Categories : Geodesy

Distribution Statement : APPROVED FOR PUBLIC RELEASE