针对月球着陆巡视探测活动中的月面着陆器与巡视器的相对定位问题,建立了月面双目标相对运动方程和状态方程,给出了同波束差分时延测量量关于双目标相对位置的测量方程,进而实现了基于统计估计方法解算双目标相对位置的算法。结合嫦娥三号探测器跟踪测量条件,利用该算法开展仿真分析。结果表明:在测量弧段达到5min以上、同波束干涉测量(SBI)时延仅有1ns随机误差的情况下,相对定位精度可达20m;测量数据存在3ns系统误差时,相对定位精度为200m,此时如果增加甚长基线千涉测量(VLBI)时延数据,可将相对定位精度提高到150m。利用嫦娥三号实测数据处理结果验证了此算法的正确性和仿真分析的有效性,可为合理制定月面双目标相对定位策略提供参考。
For relative positioning of the lander and the rover in lunar soft landing and surface reconnaissance exploration, an algorithm is presented that can be used in relative positioning for two objects based on the statistical estimation method by establishing the relative kinematic equa- tion, state equation and the measurement model of SBI (same beam interferometry). A simula- tion of this algorithm is carried out based on emulational measurement data of Chang'e-3 TT~C system. The result shows that the relative positioning error can be 20m when stochastic noise of SBI delay data is lns and tracking arc is longer than 5rain. Moreover, if there is a bias of 3ns in SBI delay data, the relative positioning error increases to 200m, which can be declined to 150m by adding VLBI delay data. The validity of the algorithm and the effectiveness of the simulation are proved by the analysis of Chang'e-3 measurement data. The algorithm can support effectively determining a strategy of relative positioning of two objects on lunar surface.