基于地基测量数据的月球DRO轨道定轨精度分析

Analysis of Cislunar DRO Orbit Determination Accuracy Using Earth-Based Simulated Observations

针对地月空间DRO探测,基于中国深空探测任务的现有测量条件,仿真分析月球DRO轨道探测器定轨预报精度。采用批处理定轨方法,选择以地球为中心天体进行轨道积分,并增加了月球非球形引力摄动。计算分析表明,在目前的测量条件下,2天短弧测距单独定轨精度为km量级,速度精度优于3cm/s,预报7天三维位置最大差异为数10km量级,速度差异小于6 cm/s;测距联合VLBI定轨精度为百米量级,速度精度优于0.4 cm/s,预报7天三维位置最大差异为千米量级,速度差异小于2cm/s,VLBI数据的加入能显著提高DRO短弧定轨预报精度。5天长弧测距单独定轨精度优于1km,速度精度优于1cm/s,预报7天三维位置最大差异小于2km,三维速度最大差异小于1cm/s,增加定轨弧长对测距数据单独定轨预报精度有显著提高。

Based on the existing tracking and measuring conditions of China’s deep space exploration missions,the orbit determination accuracy of the DRO probe was simulated and analyzed.For the Cislunar space DRO exploration,the simulation adopted batch processing orbit determination method,selected celestial bodies centered on the Earth for orbit integration,and increased non-spherical gravitational perturbation of the moon.Under the current measurement conditions,the position and velocity accuracy of 2-day short-arc orbit determination using only range tracking data were the order of km and better than 3 cm/s respectively;for 7-day predictions,the maximum differences in the position and velocity are the order of ten kilometers and 6 cm/s respectively.When using ranging data combined with VLBI data,the position and velocity accuracy were the order of hundreds of meters and less than 0.4 cm/s respectively;for 7-day predictions,the maximum differences in the position and velocity were the order of kilometers and 2 cm/s respectively,which shows that VLBI data significantly improved the accuracy of short-arc orbit determination and prediction.Moreover,the position and velocity accuracy were better than 1 km and 1cm/s respectively when using 5-day long-arc range tracking data.For 7-day predictions,the maximum differences in the position and velocity were less than 2 km and 1cm/s respectively.This shows that an increase of ranging data significantly contributes to the accuracy of orbit determination and prediction for DRO.