环月轨道器运动中的月球物理天平动问题

The Affect of Physical Libration of Moon on Lunar Satellites

采用类似对地球岁差章动的处理方法,讨论月球物理天平动对月心赤道坐标系以及月球卫星轨道的影响。在对月球物理天平动的分析表达式与高精度数值历表进行比较的基础上,给出了相应的月球引力位的变化及相应的坐标系附加摄动解,清楚地表明了对月球卫星轨道影响的规律。所获结果与数值解进行了比对,证实了从定性和定量两个方面来看本文的讨论都是有意义的,从而表明月球物理天平动分析解的简单表达式在某些问题中(特别是定轨和预报)是有实用价值的,而且在建立轨道摄动分析解时,无需像地球卫星那样,去引进混合形式的轨道坐标系,采用历元月心平赤道坐标系即可。最终表明:无论是采用数值法定轨和预报还是分析法定轨和预报,均可采用统一的月心平赤道坐标系,这可避免一些不必要的坐标转换。

We adopted the method which resemble with the one used in the effect of precession and nutation of Earth, discussed the affect of physical libration of moon on the selenocentric equatorial system and the motion of lunar satellite. Comparing the physical libration in DE405 with the analytical expression, we gave the corresponding variation of gravitational potential and the solution of additional perturbation due to the change of coordinate system, which indicates orbital variation clearly. Corresponding numerical solution ensures the result. The simple analytical solution of the lunar physical libration are useful in some problems, such as orbit determination and prediction. The solution listed in the paper enables the uniform epoch selenocentric system to be adopt for either orbit determination or prediction and avoids the unnecessary coordinate transform while the mixed orbital coordinate system which is frequently used in the works of earth satellites.