光压摄动计算中地影间断的处理

人卫精密定轨中受摄星历（或称精密星历，即状态转移），可由分析解或数值解提供，相应的定轨方法亦有分析法定轨与数值法定轨之称。对于后者，在一般情况下，现有的常微分方程数值解法（或称积分器）已能满足精度要求，除长弧定轨外，有一定问题是值得注意的，即地影“间断”问题的处理，这关系到如何在保证星历精度的前提下提高计算效率的问题。本文针对这一问题，给出了相应的改进算法，并通过数值验证表明算法的有效性。

PROCESSING OF DISCONTINUITY OF EARTH SHADOW IN COMPUTING PERTURBATION OF LIGHT PRESSURE

In the problem of artificial satellite precision orbit determination, the disturbed ephemeris (precise ephemeris, status transfer) could be obtained by either analytic or numerical method. To the latter, in general, existing numerical methods of ordinary differential equations (integrator) satisfy the numerical precision. Besides of long arc orbit determination, the problem of discontinuity of earth shadow should merit attention. This impacts the computing efficiency under conditions of keeping the precision of ephemeris computing. In this paper, this problem is discussed. Correspondingly improved methods are also given. which proved effective with numerical verification.