Richard J. Eanes

TL;DR: In this article, an analysis of 5.5 years of Lageos satellite range data reveal significant residual nodal signatures: an acceleration and annual and semiannual periods of variation in the zonal gravitational harmonic J2 coefficient and hence the polar moment of inertia.

TL;DR: An improved Earth geopotential model, complete to spherical harmonic degree and order 70, has been determined by combining the Joint Gravity Model 1 (JGM 1) coefficients, and their associated error covariance, with new information from SLR, DORIS, and GPS tracking of TOPEX/Poseidon, laser tracking of LAGEOS 1, LS1, LS2, and Stella as discussed by the authors.

TL;DR: The TOPEX/POSEIDON mission objective requires that the radial position of the spacecraft be determined with an accuracy better than 13 cm RMS (root mean square). This stringent requirement is an order of magnitude below the accuracy achieved for any altimeter mission prior to the definition of the TOPEX mission as mentioned in this paper.

TL;DR: In this article, a set of relative plate angular velocities, called GEODVEL (for GEODesy VELocity) is presented, which is based on the estimation of the position of the Earth's center and the assignment of sites to plates.

TL;DR: The TOPEX/POSEIDON (T/P) pre-launch Joint Gravity Model-1 (JGM-1) and the post-launch JGM-2 Earth gravitational models have been developed to support precision orbit determination for T/P as mentioned in this paper.