一种近地卫星自主定轨的联合滤波算法

Federal Filter Method of Autonomous Orbit Determination for Low-Earth-Orbit Satellite

地磁场具有完整的数学模型,而地磁场矢量是卫星的位置矢量函数,利用地磁场测量可以实现近地卫星的自主导航。首先建立近地卫星的高精度轨道动力学模型,提出基于星敏感器与磁强计相结合的自主导航算法,利用星敏感器输出高精度的姿态信息,同时恒星星光矢量与地磁场矢量组成两种观测模式,采用联合滤波算法对系统进行数值仿真,并对滤波算法的收敛性和仿真结果的精度进行了分析。通过对数值仿真结果的分析证实了该方案具有良好的鲁棒性和容错性。

The Earth＇s magnetic field is well modeled and is a function of the satellite＇s posiuon, therefore, autonomous Low-Earth-Orbit （LEO） satellite navigation can be achieved based on the measurement data of the onboard three axis magnetometer （TAM）. High precision satellite motion model was presented firstly, then autonomous navigation algorithm by using measurement information of star sensor and TAM was presented. The observation equation was established by using two observation models and integrating measurement vectors of star sensor and TAM based on Federal Kalman Filter. The algorithm convergence and numerical simulation precision were analyzed in detail. The results of computer simulation show that the proposed system can improve the navigation precision, robustness and reliability.