月球探测器过渡轨道的短弧定轨方法

论述的短弧定轨,是指在无先验信息情况下又避开多变元迭代的初轨计算方法,它需要相应的动力学问题有一能反映短弧内达到一定精度的近似分析解．探测器进入月球引力作用范围后接近月球时可以处理成相对月球的受摄二体问题,而在地球附近,则可处理成相对地球的受摄二体问题,但在整个过渡段的力模型只能处理成一个受摄的限制性三体问题．而限制性三体问题无分析解,即使在月球引力作用范围外,对于大推力脉冲式的过渡方式,相对地球的变化椭圆轨道的偏心率很大(超过Laplace极限),在考虑月球引力摄动时亦无法构造摄动分析解．就此问题,考虑在地球非球形引力(只包含J2项)和月球引力共同作用下,构造了探测器飞抵月球过渡轨道段的时间幂级数解,在此基础上给出一种受摄二体问题意义下的初轨计算方法,经数值验证,定轨方法有效,可供地面测控系统参考．

Method of Orbit Determination for Short Arc of Lunar Probe Transfer Orbit

The orbit determination without initial information and mono-parameter iteration is discussed. An approximate analytical solution which shows accurate status is required for the dynamic model utilized in this method. The motion of the Lunar probe into the influence sphere of the Moon can be considered as a perturbed two body problem around the Moon, while the Lunar probe is near Earth, its motion can be considered as regular perturbed two body problem around the Earth, the transfer orbit from near Earth to near Moon only can be described as a perturbed restricted three body problem. But there is no analytical solution for this kind of problem, even if the impulsive transfer method is used, the analytical solution can not be found if the Lunar gravitational perturbation is considered because of the big eccentricity (beyond Laplace limit). Thus, neither the small parameter series solution for artificial Earth satellite, nor that of the artificial lunar satellite could be used directly. In this paper, we construct a time series solution for the transfer orbit perturbed by the Earth oblateness and the Lunar attraction, and give a short arc orbit determination method under perturbed two body problem based on the time series solution. By using of the statistical information of multi-datum, this method also could be used in multi-point orbit determination, and the numerical check is given to prove the accuracy and utility of this method.