The Starlette satellite, launched by the French Centre National d'Etudes Spatiales in 1975, has provided an important means for deriving geodetic and geodynamic parameters from near-earth satellite laser ranging data. We report here on the development of a gravity field specialized for Starlette, designated PGS-1331, using the data from 1975 through 1978. We further report on the detailed analysis of the 1980 Starlette laser ranging data for the estimation of tracking station coordinates, polar motion, gravitational constant (GM), and other parameters. These analyses illustrate the improvement in our geodetic and geodynamic modeling provided by PGS-1331. Data fits for 5-day orbital arcs have been improved from the level of several meters to a few decimeters. Comparisons of the station coordinate values derived from Starlette with those from independent LAGEOS solutions indicate an rms agreement of about 25 cm. These analyses have provided an independent check of the LAGEOS-derived center of mass traking station coordinates. |