导航卫星的地面站定轨算法

导航星座轨道的长期保持是星座导航系统运营管理的重要组成部分,而现有的导航卫星地面定轨算法又存在精度不高或计算量大不适合工程应用的问题。为此,研究了单向、被动测量模式的导航卫星地面定轨算法。基于单向伪距观测,将导航卫星钟差参数作为状态量,推导了滤波算法的状态方程、测量方程,并最终建立了滤波器模型。以不同轨道面的4颗GPS导航卫星为例进行了2天的仿真试验,考虑卫星的可见性仿真中加入了测量中断,并设计在测量恢复后重启滤波算法。仿真结果表明,4颗卫星的轨道位置估计精度可以达到米级,钟差随机偏差的估计精度可以达到纳秒级,并且在滤波中断后重启滤波器,仍然可以达到此估计精度,表明此定轨算法具有收敛性和稳定性。

Algorithm for Ground-base Orbit Determination of Navigation Satellites

Precision of navigation satellite orbit determination is an important factor for the operation of the constellation navigation system.However,there are many problems in the field of navigation satellite ground-base orbit determination,such as low accuracy and high computational complexity.To find potential solutions of these problems,the ground-base orbit determination algorithm of navigation satellites was studied by one-way and passive measuring mode.The state process and the observation model were derived to establish the filter model,with pseudo-range between a monitor station and a satellite as the measurement,and parameters of the satellite clock as elements of the filtering state vector.Based on four GPS satellites in different orbital planes,a two-day simulation was designed to verify the algorithm.Considering the visibility of the satellite,an interruption of measurement between measuring process was introduced,a strategy for restarting the filter was proposed.The simulation results show that the position estimation error is less than 10 meters and the clock bias estimation error is less than 10 ns for all the four satellites.Furthermore,it could keep the previous filtering performance after the filter restarting.All these results indicate that this algorithm is convergent and stable.