再入返回飞行试验深空网干涉测量应用分析

Application of CDSN Interferometric Tracking in Reentry Return Flight Test Missions

鉴于我国深空测控网的深空干涉测量系统在探月三期再入返回飞行试验中首次正式执行任务,北京深空干涉测量中心组织佳木斯、喀什深空站对再入返回飞行试验器进行了高精度干涉测量。针对深空站天线无法短时交替观测射电源,从而无法进行干涉测量系统差标校的问题,利用基于稀疏标校数据平滑内插、高精度钟差建模、环境参数时延补偿的数据综合处理策略,实现了干涉测量系统差高精度标校。利用飞行试验器VLBI(Very Long Baseline Interferometry,甚长基线干涉测量)信标下行信号进行干涉测量获取时延观测量,用于飞行试验器联合定轨。联合定轨残差结果表明,深空网干涉测量时延测量精度在1ns水平,对应约100nrad测角精度,可以为飞行试验器精密定轨提供高精度测量数据支持。

While CDSIS（China＇s Deep Space Interferometry System）based on CDSN（China＇s Deep Space Network）carried out China＇s reentry return flight test mission for the first time,BDSIC（Beijing Deep Space Interferometry Center）scheduled participation of Jiamusi and Kashi deep stations in the mission.As deep space stations could not alternately observe spacecraft and quasars in short-term time intervals in the interferometry mission,an integrated interfereometry data processing strategy was developed and it consisted of sparse data smoothing,differential correction calibration,high precision clock error modeling and environmental parameters delay compensation to achieve high precision differential interferometry measurement system calibration.VLBI（Very Long Baseline Interferometry）beacon signals of the flight test spacecraft downlink were utilized for interferometry signal processing to obtain delay observations,which were provided to spacecraft orbit determination system for combined orbit determination.Orbit determination residual error results show that CDSIS interferometry delay accuracy was at the level of 1ns,corresponding to angular accuracy of about 100 nrad,providing high accuracy measurement observations for accurate orbit determination for the flight test spacecraft.