It is efficient to compute long-period and secularperturbations by numerical integration, but the classical analytic solution may be used to calculate the short-period perturbations.
用数值积分来计算长周期和长期摄动，而用经典分析解的表达式来计算短周期摄动，这是很有效的。
2
The mechanism of Low earth orbit(LEO) satellite formation secular evolvement under the influence of gravitational perturbations is studied.