[G07-2] GGOS focus on reference frames

[G07-2-05] Effective expansion of satellite laser ranging network for improving geodetic products and satellite orbits

^○Toshimichi Otsubo¹, Koji Matsuo², Yuichi Aoyama³, Keiko Yamamoto⁴, Thomas Hobiger⁵, Toshihiro Kubo-oka⁶, Mamoru Sekido⁶, Urs Hugentobler⁷, Rolf Koenig⁸ (1.Hitotsubashi University, Kunitachi, Japan, 2.Geospatial Information Authority of Japan, Tsukuba, Japan, 3.National Institute of Polar Research, Tachikawa, Japan, 4.National Astronomical Observatory of Japan, Mitaka, Japan, 5.Chalmers University of Technology, Gothenburg, Sweden, 6.National Institute of Information and Communications Technology, Kashima, Japan, 7.Technical University of Munich, Munich, Germany, 8.Deutsches GeoForschungsZentrum, Wessling, Germany)

About 35 satellite laser ranging stations are being operational all over the world but huge regions on the globe are not covered. We assume a new station is going to be added to the existing station network and therefore we like to evaluate the effectiveness of each location. Realistic numbers of observations for a new station are numerically simulated, based on the actual data acquisition statistics of the existing stations. Multiple-satellite-combined orbit determination is then conducted with and without a new station, and the estimated errors are investigated.

A new station placed in the Southern hemisphere is found to be effective in general. It is revealed that the most effective place differs according to the geodetic parameter. The X and Y components of the geocenter and the sectoral terms of the Earth's gravity field are largely improved by a station in the polar regions. A middle latitude station best contributes to the tesseral gravity terms, and, to a lesser extent, a low latitude station best performs for the Z component of the geocenter and the zonal gravity terms. With the existing stations the quality of satellite orbits is found to be relatively poor in the Southern hemisphere, but a new high latitude station in Antarctica enhances locally the accuracies so they behave close to uniform over one orbit.