AAS 97-702

IMPROVEMENTS IN MARS GRAVITY FIELD DETERMINATION USING RIDGE-TYPE ESTIMATION METHODS

C.F. Minter - Naval Surface Warfare and D.A. Cicci - Auburn University

Abstract

The objective of this research was to improve the accuracy of the Jet Propulsion Laboratory's Mars gravity field Mars50c, using ridge-type estimation methods. Calculation of the gravity field coefficients involves solving a large, ill-conditioned system of linear equations, whose solution leads to erroneous estimates if not augmented by appropriate a priori information. This study used ridge-type estimation methods to optimally weight a set of a priori constraints to obtain more accurate estimates. The computed gravity field, AUMGM9, was compared to Mars50c, and results show that AUMGM9 provides more accurate gravity field coefficients than does Mars50c.