在嫦娥一号探月工程中求定月球重力场

On the determination of lunar gravity field in the Chinese first lunar prospector mission

月球重力场制约着近月外空间物体的运动,同时环月飞行器的运动也反映了月球重力场的作用.本文结合我国嫦娥一号探月工程,探讨了利用月球卫星的地面跟踪资料,求定月球重力场的基本理论和方法,分析了环月卫星的轨道高度、地面跟踪采样时间间隔和跟踪精度等对求定月球重力场的影响.若单独利用我国嫦娥一号探月工程的地面跟踪数据,恢复30阶次左右的月球重力场模型是一个比较实际的目标.地面跟踪最好能以75s的时间间隔进行采样,数据连续提供时间应不少于30个昼夜,月球卫星星下点的月面轨迹间距不大于110km .

Lunar gravity field acts on any moving object near the lunar space, and also is reflected by the motion of a lunar spacecraft. Some basic theories and techniques for the determination of lunar gravity field with deep space tracking data of a satellite are discussed in the paper. Analyzing the orbit height of a lunar satellite, the interval of sampling time provided by tracking stations on the Earth, and the accuracy of the tracking data, it is possible to obtain 30th degree lunar gravity field if only using the tracking data of the Chinese first lunar prospector mission. In this case the time interval of the earth tracking data should be no shorter than 75 seconds, the continuous tracking time should be no less than 30 day and night, and the interval of the sub lunar points on the lunar surface should be no larger than 110km.