Precise orbit computation for the Geosat Exact Repeat Mission

摘要: We have conducted an extensive investigation of orbit determination strategies for the Geosat Exact Repeat Mission (ERM). The goal our studies is to establish optimum geodetic parameters and procedures computation most accurate orbits possible apply these routine during ERM following purposes: (1) enhance value oceanographic investigations by providing user community with improved ephemerides, (2) develop techniques upcoming altimetric mission TOPEX/POSEIDON, (3) assess radial accuracy obtainable recently developed gravity models. To this end, ephemerides entire first year been computed using GEODYN II program on Cyber 205 supercomputer system at Goddard Space Flight Center. GEM-T1 solution was used in developing solutions 25 separate 17-day arcs. Estimated errors reduced from a level 3-m root-mean-square (rms) operational about 85-cm level. Both precision were produced same tracking data collected U.S. Navy's Operational Network, so improvement due force measurement modeling. Recently, more field, GEM-T2, has become available. Preliminary tests performed GEM-T2 model, along TRANET-2 Doppler that acquired, suggest accuracies 35 cm rms can be achieved Geosat.