一种卫星天文自主定轨定姿方法研究

利用安装在卫星上的太阳敏感器和紫外敏感器测量出的卫星—太阳、卫星—地球和卫星一月球方向矢量，并利用雷达测高仪测出的地心距作为观测量，提出采用广义卡尔曼滤波方法实时地确定卫星绕地球飞行的轨道，同时确定出卫星的对地姿态．对自主定轨进行了数学仿真，分析比较了采样周期、轨道倾角、轨道偏心率和轨道高度等因素对定轨精度的影响．总结了其变化规律，该方法可用于提高卫星自主定轨精度．

A METHOD OF CELESTIAL AUTONOMOUS ORBIT DETERMINATION AND ATTITUDE DETERMINATION FOR SATELLITE

An autonomous real-time orbit determination for satellite flying around the Earth by the extended Kalman filtering is proposed in this paper. The observables are as follows, Satellite-Sun direction vector measured by Sun sensor, Satellite-Earth direction vector and Satellite-Moon direction vector measured by ultraviolet sensor, and the geocentric distance measured by radar altitude. Moreover, the satellite attitude to the Earth is determined. The simulation results show that orbit determination precision is better than 200m. By simulation experiments of autonomous orbit determination, the effects of sample period, orbit inclination, orbit eccentricity and orbit height on orbit determination precision are analyzed and compared. The changing law is submitted, which can improve satellite autonomous orbit determination precision.