18参数广播星历分析研究

针对18参数广播星历模型对混合星座（包含GEO（地球同步轨道）、IGSO（倾斜地球同步轨道）、MEO（中地球轨道））的拟合精度和稳定性问题,利用摄动理论中的分析方法研究18参数广播星历模型新增参数的物理意义,通过数值仿真比较分析18参数模型与16参数模型对混合星座的拟合精度和稳定性。分析研究表明,新增2个参数可以较好地逼近轨道变化的长周期项,相同拟合弧长的拟合精度比16参数提高了50%左右,但受短周期项影响,拟合不够平稳,同时由于轨道变化特征的差异,对GEO和IGSO卫星的拟合不如MEO卫星稳定。数值仿真结果表明,要保证稳定性必须增加拟合弧长,但拟合精度会有一定下降,18参数条件下,MEO卫星选用3h拟合弧长能保持很好的稳定性,GEO和IGSO卫星则需要选择5h拟合弧长。

Research on 18 Elements Broadcast Ephemeris Model

The physical meaning of the new elements of 18 elements broadcast ephemeris model is studied for analysis of its fitting accuracy and stability for mixed constellation encompassing GEO,IGSO and MEO satellites.Comparison is made on the fitting accuracy and stability between 16 elements model and 18 elements model with both analytical and numerical methods.It is found that the new elements can be fit for the long period term of orbit perturbation very well but not for the short period term.The fitting accuracy is increased by about 50%,but the fitting stability is worse.Results of numerical simulation show increasing fitting arc length increases fitting stability,but may decrease the fitting accuracy.Fitting stability for MEO satellites is maintained using 3 hour fitting arc length while 5 hour fitting arc length is required to maintain fitting stability for GEO and IGSO satellites.