Comparison and evaluation of the new Russian global geopotential model to degree 360

A new Russian global geopotential model was created with the use of detailed gravity data, satellite tracking and altimetry data. Through the research and operations executed, the global Earth gravity field model GAO-98 with the resolution level corresponding to the geopotential expansion into spherical harmonics up to 360th degree has been developed. The main parameters of the model developed are a set of mean anomalies for 30’ x 30’ — blocks covering the whole surface of Earth and a set of spherical harmonics to 360th degree resulted from the expansion of the geopotential. The model is destined mainly for use in highly accurate quasigeoidal height determination, which will significantly improve the efficiency of implementing GPS/GLONASS satellite equipment unto the routine geodetic operations of the Federal Service of Geodesy and Cartography of Russia. The accuracy of absolute quasigeoid heights by use of the model developed is for most regions of Russia M_ç = ŷ20–25 cm. The test data that we used for model evaluations include geoid undulations (or height anomalies) determined from GPS positioning and level observations, global geopotential models EGM96, global marine gravity field from Russian GEOIK altimetry data and from GEOSAT, ERS-1, TOPEX/POSEIDON data. Future problems geoid determinations discussed.