相对差分单向测距(ΔDOR)技术在探月工程中的应用研究

Applications of Delta Differential One-way Ranging(ADOR) to Lunar Exploration Program

相对差分单向测距(△DOR)是一种高精度测角技术,在深空探测任务的高精度测定轨方案中得到广泛应用.介绍了△DOR测量的基本原理及CCSDS(国际空间数据系统委员会)关于△DOR测量的相关标准.针对中国探月工程月面软着陆任务提出的高精度测定轨要求,分析了△DOR测量的信号形式、工作模式以及测量精度,推导了解模糊过程.研究表明,△DOR测角精度达到25nrad,对应到月球上的距离约为10m.

Delta Differential One-way Ranging （△DOR） is used for high precision angle measure- ment in many deep space exploration programs. The fundamentals of ADOR are introduced. Also, recommendations about ADOR of CCSDS （Consultative Committee for Space Data System） are presented. According to the high precision and real-time navigation requirements, the ADOR measurement schemes are designed for China＇s lunar exploration program whose current object is soft-land on the moon. The angle measurement precisions are analyzed in terms of the current performances of on-board and ground TT＆C equipments. The resolution of the cycle ambiguity is presented. Research results show that the angle measurement precision is 25 nrad, which corresponds to about 10 m on the moon. Further, the cycle ambiguity of DOR measurements can be resolved correctly.