当前月球卫星主要依靠地面站进行遥控遥测。针对月球卫星与地面站距离较远, 信号延迟大, 地面基线短和月球背面不可见弧段等因素, 提出一种基于X射线脉冲星的月球卫星自主导航方法。结合月球卫星轨道动力学方程和脉冲星提供的量测信息, 分析了X射线脉冲星的距离测量精度, 并利用PWCS可观测分析方法对系统进行可观测分析, 最后采用扩展卡尔曼滤波进行状态估计。仿真结果表明, 该导航方案具有较好的稳定性和估计精度, 能够适用于月球卫星的自主导航。

Currently orbit determination for lunar satellite is supported by ground stations for remote telemetry, but the distance between lunar satellites and ground stations is too long, signal delay is large. In order to reduce the dependence of navigation systems to ground based operations and achieve more autonomy, an autonomous navigation for lunar satellite using X ray pulsars is proposed. Combined with lunar satellite orbit dynamics equations and pulsars measurement, we discuss the performance of X ray pulsars navigation by analyzing the transformation error of TOA. In addition, the observability of the system is discussed by Piece Wise Constant System (PWCS) theory, and the system is completely observable in the theoretical analysis. The Extended Kalman Filter (EKF) is used to estimate the states. Simulation results show that the navigation system can provide positions and velocities of lunar satellite with a high accuracy. Thus, it is a suitable scheme for autonomous navigation of lunar satellite.