抗差估计在星载GPS卫星非差运动学定轨中的应用

Application of Robust Estimation in GPS-Based Satellite Zero-Difference Kinematic Orbit Determination

针对星载GPS卫星非差运动学定轨的特点,提出将抗差估计应用于星载GPS卫星运动学定轨,一方面尽量保留来自每颗GPS卫星的观测值,保持较强的卫星几何强度,避免轨道求解出现奇异;另一方面,采用等价权思想,有效地降低质量较差的观测值对定轨结果的影响,保证定轨精度．还采用CHAMP卫星的实测GPS数据验证了新方案的可行性和有效性．

Aiming at the characteristics of zero-difference kinematic precise orbit determination （POD） of Low Earth Orbiters （LEO） equipped with a GPS receiver, it presents a new scheme, which uses robust estimation to determine LEO＇s kinematic orbit based on GPS data. On the one hand, robust estimation can avoid the singularities in the kinematic orbit solution by retaining as much data as possible from GPS satellites and keeping strong geometry, and on the other hand, applying the idea of equivalent weight, robust estimation can reduce the unfavorable effect of bad observations to the orbit solution, and guarantee the orbit solution＇s accuracy. A real example was performed, and the results indicate that the new scheme is feasible and effective.