Abstract:

We have focused on the gathering, evaluation, and pre-analysis (verification and validation) of the available unclassified point gravity anomaly data. This massive re-analysis will first predict 5´x5´ area-mean values of gravity anomalies (accompanied by reliable error estimates). These 5´x5´ mean values will be the basis for the creation of coarser grids of mean values (30´x30´ and 1°x1°) that will be used for the formation of surface gravity normal equations to be combined with the GRACE normal equations. So far we have developed and verified: (a) a global topographic database employing the latest release of SRTM-derived elevations in 30˝x30˝ resolution, and, (b) a global calculation of Residual Terrain Model (RTM) effects in 30˝x30˝ resolution. We have also used preliminary versions of our 5´x5´ gravity anomaly database, in combination with GGM02S, to develop and evaluate preliminary gravitational models complete to degree and order 2160 (PGM2004A, PGM2005A). We will present these results, and discuss our future plans.