近地卫星运动的坐标系附加摄动在拟平均根数法中的处理

在常用的历元地心天球坐标系中研究和处理近地卫星的轨道问题,就必须考虑由于地球赤道面摆动所引起的坐标系附加摄动,正因为如此,给实际工作带来一些麻烦.关于这一问题,曾提出了一种针对瞬根数和平根数之间的转换(仅与坐标系附加摄动的短周期项有关)的解决途径,但并未涉及采用分析法进行轨道外推的有关问题(这与坐标系附加摄动的长期和长周期项有关),这对处理近地卫星的轨道问题而言显然是不完整的.这里结合拟平均根数法进一步改进原提出的方法,较完善地解决这一坐标系附加摄动的计算问题.在此前提下,对于卫星定轨和预报及其相关工作,无论是采用数值法还是分析法,均可采用同一坐标系,即历元(目前是J2000.0)地心天球坐标系.

The Application of Quasi-Mean-Element-Method to LEO under Additional Perturbation due to Change of Coordinate System

It is necessary to consider the additional perturbation caused by the oscillation of Earth's equator when working on the low earth orbit(LEO).Since 1960s,an intermediate orbit coordinate system using true equator and mean equinox(TEME)is introduced.It effectively solves the problem and has been widely used in various applications till today.But this traditional frame is purely conceptual and has always been a trouble in converting between these systems especially for those who are unfamiliar with celestial frames.As proved in a previous paper,it is possible to avoid the intermediate TEME frame and conversions between osculating elements,and mean elements can be completed in a consistent geocentric celestial coordinate system where only short-period terms are required.Here with the improved secular and long-period terms,it is further available to predict the orbit analytically with quasi-mean-element-method all in the same celestial frame,reaching the accuracy of 10~(-6)in Earth's radius.The results show and suggest that celestial coordinate system(J2000.0 for the time being)can be used throughout any applications without having to introduce TEME system as intermediate frame any more.