Improved-GRACE卫星重力轨道参数优化研究

RESEARCH ON OPTIMAL SELECTION OF ORBITAL PARAMETERS IN IMPROVED-GRACE SATELLITE GRAVITY MEASUREMENT MISSION

基于改进的半解析法,利用激光干涉系统星间速度误差、GPS接收机轨道位置误差和轨道速度误差以及加速度计非保守力误差影响累计大地水准面的联合误差模型,开展了我国Improved-GRACE卫星重力测量计划轨道参数的优化选取论证。模拟结果表明:1)在300阶处,基于350km轨道高度估计累计大地水准面的精度为3.993×10-1m,基于300km和250km轨道高度估计精度分别提高了8.770倍和77.145倍,基于400km和450km轨道高度估计精度分别降低了8.718倍和75.307倍;2)基于50km星间距离估计累计大地水准面的精度为3.993×10-1m,基于110km和220km星间距离估计精度分别降低了1.259倍和1.395倍;3)我国将来首颗Improved-GRACE重力卫星的平均轨道高度和平均星间距离设计为350km与50km较优。

The optimal selection of orbital parameters in the future Improved-GRACE satellite gravity measurement mission in China is carried out by using the combined model of cumulative geoid height errors influenced by the intersatellite range-rate error of interferometric laser ranging system, orbital position and velocity errors of GPS receiver and nonconservative force error of accelerometer based on the improved semi-analytic method. The simulated results show as follows. Firstly, at degree 300, cumulative geoid height error is 3. 993 ×10^-1 m at 350 km orbital altitude, the accuracies are improved respectively 8. 770 times and 77. 145 times at 300 km and 250 km compared with that at 350 km orbital altitudes, and the accuracies are decreased respectively 8. 718 times and 75. 307 times at 400 km and 450 km compared with that at 350 km orbital altitudes. Secondly, cumulative geoid height error is 3. 993 ×10^-1 cm as using 50 km intersatellite range, and the accuracies are reduced respectively 1. 259 times and 1. 395 times using 110 km and 220 km compared with that using 50 km intersatellite ranges. Finally, the opti- mal designs of average orbital altitude 350 km and mean intersatellite range 50 km are suggested in the future first Improved-GRACE gravity satellite in China.