摘要
GPS广播星历参数具有物理意义明确、参数少、精度高等优点,可以考虑将它应用于其他卫星导航系统。但是GPS系统的卫星构成比较单一,而其他卫星导航系统可能包含中地球轨道 (MEO)、倾斜地球同步轨道(IGSO)和地球静止轨道(GEO)等多种不同类型的中高轨卫星。分析了采用GPS广播星历参数时,MEO、IGSO和GEO卫星的广播星历拟合精度,特别讨论了轨道倾角接近于0的GEO卫星的广播星历拟合精度,并给出了相应的改进措施。计算表明,对于 MEO卫星,2 h的广播星历拟合精度(三维位置)可达厘米级;对于IGSO卫星和轨道倾角较大的GEO卫星,4 h的广播星历拟合精度约为0．1 m,径向位置误差在厘米量级;而对于轨道倾角接近于0的GEO卫星,若不采取特殊措施,由于轨道倾角和升交点经度统计相关,其广播星历拟合精度很差,为此提出了一种坐标转换方法。采用此方法后的广播星历拟合精度可达0．1 m,径向位置误差为厘米量级。
The broadcast ephemeris parameters for GPS may be used in other satellite navigation system. Usually a satellite navigation system includes different kinds of satellites, for example, MEO （Medium Earth Orbits） satellites, IGSO （Inclined GeoSynchronous Orbits） satellites and GEO （Geostationary Earth Orbits） satellites. This paper studies the accuracy of broadcast ephemeris for above different kinds of satellite orbits using the broadcast ephemeris parameters for GPS, and especially analyses the accuracy of broadcast ephemeris for GEO satellites with near-zero-inclination. For MEO satellites, the fitting accuracy for 2 hours fitting arc can reach em magnitude. For IGSO satellites and GEO satellites with not near-zero-inclination, the fitting accuracy for 4 hours fitting are can reach 0.1 m, and the radial position error is cm magnitude. For GEO satellites with near-zero-inclination, the fitting accuracy is not good enough because of the correlation of parameters. A method of coordinate transformation is adopted to avoid correlation and to improve the fitting accuracy. Using this method for GEO satellites with nearzero-inclination, the fitting accuracy for 4 hours fitting are can reach 0.1 m, and the radial position error is em magnitude.
出处
《天文学进展》
CSCD
北大核心
2006年第1期81-88,共8页
Progress In Astronomy
基金
国家自然科学基金资助项目(40374002)
中科院知识创新工程重要方向资助项目(KJCX2-SW-T1)
