Preliminary Results from the Joint GSFC/DMA Gravity Model Project

The NASA Goddard Space Flight Center (GSFC) and the U.S. Defense Mapping Agency (DMA) with the aid of other organizations such as The Ohio State University are cooperating in a joint effort to determine a significantly improved degree 360 spherical harmonic model representing the Earth’s gravitational potential. This new model will be of immediate use in defining an undulation model that will be the basis for an enhanced WGS-84 geoid, but the model will be general in use and will provide enhancements for a wide range of applications. The development of the new model is driven, in part, by the need to determine an accurate geoid undulation model that will be the vertical reference surface for WGS-84. In addition, the new geoid model will help satisfy increasingly important studies in ocean circulation (sea surface topography) and geodetic positioning through GPS.