“嫦娥4号”高精度VLBI测轨技术

High-Precision VLBI Orbit Measurement Technology in the Chang’E-4 Mission

"嫦娥4号"在国际上首次实现了月球背面软着陆和巡视勘察。"嫦娥4号"中继星任务中首次创新性使用S波段双差分单向测距(Delta Differential One-way Ranging,ΔDOR)测量技术,自主研制的S波段ΔDOR观测数据处理系统在探测器任务期间,首次实现了甚长基线干涉测量(Very Long Baseline Interferometry,VLBI)系统分时快速转换观测中继星和探测器;利用天马射电望远镜对中继星天线进行了在轨指向标定。深入分析了VLBI需要解决的主要技术问题,提出了具体的解决措施,通过重点对中继星、探测器实时任务期间的测量结果的分析,得出这些技术手段对任务目标的完成具有重要作用。

Chang’E-4(CE-4)achieved the soft landing and patrol survey on the far side of the Moon for the first time in the world.The S-bandΔDOR measurement technology is used in the relay satellite mission,and the new S-bandΔDOR observation data processing system is developed.During the prober mission,the VLBI system realized fast time-sharing observations for the relay satellite and lander-rover combination prober for the first time;and the Tianma radio telescope is used to calibrate the relay satellite antenna in orbit.Considering the characteristics of CE-4,the key technical issues to be solved by the VLBI technology are analyzed,and specific measures are proposed.The analysis of the measurement results during the real-time mission of the two spacecraft show that these technical measures play important roles in the accomplishment of mission goals.