增强型轨道列表星历及其在北斗混合星座中的应用

为了改进北斗卫星数小时内的力模型精度，分析日月引力摄动和光压摄动的短期变化特性，提出基于二次多项式逼近日月引力摄动的15参数增强型轨道列表星历模型。利用该星历模型对北斗的5 GEO + 5 IGSO + 4 MEO混合星座进行了为期11天的星历拟合实验。结果表明，三类卫星在非地影期的2小时星历拟合精度优于1 cm。增强型轨道列表星历模型没有轨道根数的潜在奇点问题，能够为我国北斗星座和星基增强系统提供更多可行的星历模型选择。

Enhanced Orbit Catalogue Ephemeris and its Application in BeiDou Mixed Constellation

In order to suit for the ephemeris of BDS adopted currently, an enhanced 15-parameter ephemeris model is proposed by improving the force model. Firstly, the short-term variation characteristics of the lunisolar perturbation and the solar radiation pressure are analyzed. Then a quadratic polynomial is used to approximate the lunisolar perturbed acceleration. Ephemeris fitting experiments are performed for the 5 GEO+5 IGSO+4 MEO mixed constellation of BDS during 11-day period. The results show that two hours’ fitting accuracy of all the 14 satellites is better than 1 cm during non-eclipse period. The proposed enhanced orbit catalogue ephemeris owns the merit of not suffering the singularity problem of orbit elements, and can provide more feasible selections of ephemeris model for the BeiDou constellation and satellite based augmentation system.