姿态和光压模型对北斗导航卫星精密定轨的影响分析

通过GPS/BDS双系统联合定轨给出北斗系统新老卫星的轨道精度变化特征，分析不同姿态控制模式对卫星精密定轨的影响及其原因；针对光压模型的不足，讨论两种改进的定轨策略对北斗系统精密定轨的适用性。结果表明，当太阳矢量与卫星轨道面的夹角小于4°时，采用动偏-零偏转换模式的IGSO/MEO卫星会有明显的轨道精度下降，而IGSO-6卫星的轨道精度变化较为平稳，没有明显的精度衰减；ECOM光压模型较适用于IGSO-6卫星，但不适用于其他卫星；两种改进的定轨策略都能在一定程度上提高北斗导航卫星精密定轨的精度，可为北斗系统精密定轨提供参考。

A Study on the Impact of Yaw-Attitude and Solar Radiation Model on Precise Orbit Determination for Beidou Navigation Satellites

Based on the results of GPS/BDS dual systems joint orbit determination, the orbit quality variation characteristics of new and old satellites are given, and the impacts of different attitude control modes on POD are analyzed. For the defects of the solar radiation pressure (SRP) model, we propose two modified POD strategies and discuss their availability. The results show that when the acute angle between sun vector and orbit-plane is less than 4 degrees, the yaw attitudes of old IGSO and MEO satellites are switched and significant orbit quality degradation is observed, while the orbit quality of the IGSO-6 satellite is stable. The ECOM SRP model is suitable for the IGSO-6 satellite, but not for old BDS satellites. Both modified POD strategies can improve the orbit accuracy of BDS satellites to some extent.