深空探测器同波束相位参考成图相对定位方法

摘要

针对我国后续深空探测任务中高精度相对定位需求，提出了采用天文同波束相位参考成图技术进行深空探测器相对定位的方法。首先建立适用于深空探测器信号特点的同波束相位参考成图相对定位模型，然后分析信号带宽和 UV 覆盖两个因素对测量精度的影响。最后利用我国 VLBI 观测网(CVN)在2013年15、20和21日接收的嫦娥三号着陆器和玉兔号巡视器下行同波束数据，处理得到了巡视器在5个环拍点相对着陆器的位置，验证了本文方法的可行性及其对探测器下行信号的强适应性。与视觉定位结果的对比表明，巡视器相对着陆器定位精度达到米级。%To meet the needs of high accuracy relative position determination in deep space explorations, a new method is proposed based on the same beam phase-referencing imaging technique that originates from the radio astronomy.Fi rstly,the same beam phase-referencing imaging measurement model for spacecraft positioning is bui lt.The very long basel ine interferometry (VLBI)imaging principle and the phase difference between two spacecrafts are derived.Then,two precision affecting factors are analyzed, including the signal bandwidth and the UV coverage.The di rty beams formed by different station numbers and different observation lengths with the Chinese interferometry network are simulated.Final ly,with the same beam observation data of the Chang’E-3 lander and rover from the Chinese VLBI network (CVN)on December 15,20 and 21,2013,the Yutu rover lunar surface positions are determined with accuracy of about 1 meter.The results show the feasibi l ity and high accuracy of this method,which is wel l-adapted to the spacecraft signals without special beacons.