基于GPS对地球同步轨道自动转移飞行器进行导航的可行性分析

研究利用GPS对地球同步轨道自动转移飞行器进行导航的方法,分析了飞行器在转移过程中可用的GPS卫星数目,在地心惯性坐标系下建立了惯导误差和GPS的伪距、伪距变率模型,采用渐消因子的自适应卡尔曼滤波对飞行器进行组合导航.仿真结果表明,可用GPS卫星的数目随着飞行器高度的增高而减少,因此无法利用单一历元观测信息直接对飞行器导航.但采用多历元观测信息和动力学模型相结合的滤波方法可对飞行器进行组合导航,当飞行器初始位置偏差为1 km,初始速度偏差为1 m/s,伪距及伪距变率观测均方差分别为10 m和0.05 m/s时,地球同步轨道自动转移飞行器的最终位置偏差小于50 m,速度偏差小于0.02 m/s. 

Feasibility of Geosynchronous ATV Navigation Based on GPS

The GPS is used to determine the orbit of Geosynchronous Autonomous Transfer Ve- hicle(GATV).The visibility of the GPS satellites relative to the vehicle is analyzed in this paper. Moreover,inertial error,pseudorange and delta pesudorange models are established in the earth centered inertial coordinate system.The adaptive kalman filter with a fading factor is applied for the vehicle orbit determination.Simulation results show that even slope-lobe signal is used,GPS satellite visibility becomes lower as the vehicle flies higher.Usually,the visibility can not be improved effectively by increasing the receiver antenna gain and direct orbit determination is infeasible with only one epoch GPS observation.It is indicated that by using kalman filter,in the conditions of 1 km initial position deviation,1 m/s initial velocity deviation,10 m pseudorange mean square error and 0.05 m/s delta pseudorange mean square error,the final position deviation is smaller than 50 m while the velocity deviation is smaller than 0.02 m/s.