深空探测器精密定轨与重力场解算系统(WUDOGS)及其应用分析

Wuhan University Deep-space Orbit Determination and Gravity Recovery System(WUDOGS) and Its Application Analysis

WUDOGS是武汉大学自主研发的深空探测器精密定轨与重力场解算软件系统。该软件目前已经具备月球、火星探测器的高精度定轨能力。本文首先简要介绍了WUDOGS设计思路及其主要功能,然后重点介绍了WUDOGS与国际上领先水平的行星探测器精密定轨软件系统GEODYN-Ⅱ的交叉验证测试过程。结果表明:对于探测器的轨道预报,WUDOGS与GEODYN-Ⅱ的1个月位置差异小于0.3mm,2d位置差值小于5×10-3 mm;双程测距、双程测速的理论计算值和GEODYN-Ⅱ的差值分别在0.06 mm、0.002 mm/s的水平;对月球探测器"嫦娥一号"的精密定轨显示WUDOGS和GEODYN-Ⅱ符合在2cm水平,对火星探测器MEX的精密定轨显示WUDOGS和欧空局精密轨道符合在25m水平。该软件目前的研发情况及其与国外研究水平的对比表明WUDOGS具有良好的应用前景,对满足我国后续深空探测发展的需求以及深空探测器精密定轨软件的研发具有重要意义。

WUDOGS(Wuhan University deep-space orbit determination and gravity recovery system) is a software system designed for deep spacecraft precise orbit determination and planetary gravity recovery, developed independently at Wuhan University. WUDOGS now has the function for Lunar and Mars spacecraft precision orbit determination. Its design pattern and main function are briefly introduced. The cross verification test(CVT) between WUDOGS and state of the art planetary precise orbit determination software GEODYN- are elaborated. The results show that:for orbit propagation, with all the same forces and other configuration, the predicted orbit difference in R, T, N directions are less than 0.3 mm for one month arc, 5×10-3mm for 2 days arc, compared with GEODYN-; the difference RMS of computed values of observables for two-way range and two-way range rate is at levels of 0.06 mm and 0.002 mm/s respectively; for Chinese Chang'E-1 POD, the reconstructed orbit difference between WUDOGS and GEODYN- is at 2 cm level, for ESA MEX POD, the reconstructed orbit difference between WUDOGS and ESA is at 25 m level. Current developing situation of WUDOGS and comparison with international research level show that WUDOGS has a good application prospect, which will be important for meeting the demand of Chinese future planetary exploration and the development of deep space spacecraft POD software. © 2017, Surveying and Mapping Press. All right reserved.