北斗卫星导航系统混合星座的光压摄动建模和精度分析

卫星帆板及本体受照情况变化复杂，导致卫星光压摄动力的变化难以准确模制，既是动力学定轨的最大误差源，也是定轨预报精度降低的主要原因。针对此问题，采用北斗地面系统的区域监测网数据，详细比较了3种主要的经验模型（T20模型、ECOM5参数模型、ECOM9参数模型）对不同卫星的适用性情况。结果显示，在春秋分前后，地球同步轨道（geosynchronous earth orbit，GEO）卫星使用ECOM9参数模型最好，其解算的卫星钟差与星地双向钟差的互差标准差优于2 ns；对于倾斜地球同步轨道（inclined geosynchronous satellite orbit，IGSO）卫星和中地球轨道（medium earth orbit，MEO）卫星，无论是在动偏期间还是姿态模式转换期间，T20模型表现出更好的适用性。不同于此前国内外学者的相关研究，试验表明，对BDS混合星座的不同类型卫星、同一卫星的不同时段，应采用不同的经验太阳光压模型，以获得更高的定轨和预报精度。

Modeling and Precision Analysis of Solar Radiation Pressure for BDS Hybrid Constellation

Since accurate satellite physical models are difficult to conclude, the empirical solar radiation models are key to improve the orbital accuracy. With the measurements from the regional network of BDS ground control, three widely-used solar radiation pressure(SRP) empirical models (T20 model, ECOM5 model, ECOM9 model) are used to determinate the orbits of the three kinds of satellites and evaluate the effectiveness. Result shows that ECOM9 model has a better performance when the sun closes to the GEO satellite during the spring (or autumn) equinox and the standard deviation (STD) of the difference between satellite clock offset from orbit determination and two-way satellite-ground clock offset is better than 2 ns, which is evidently improved over that of T20 model and ECOM5 model. For IGSO/MEO satellite, T20 model has a better performance whether during the period of satellite attitude switch or orbit-normal mode. Different from the previous research, the conclusion of this paper shows that for the different types of BDS satellites and the same satellite at different times, we should use different SRP model to obtain a higher orbit determination and prediction accuracy.