摘要
本文对现有初轨计算方法进行病态性分析与误差分析；研究结果表明：病态对现有初轨算法的影响，主要来源于法方程系数中包含观测误差．系数行列式愈大，定轨精度的损失愈多，当■被随机误差项△μ淹盖时，现有初轨算法将失效．此外，仿真结果还显示：■与△μ的大小还极大地依赖观测弧段的空间位置，当观测弧段包含近站点作为中点时，■最大，而■小，此时定轨精度较高；当观测弧段位于近站点的某一侧时，■小，而■大，此时定轨精度较低，观测弧段愈偏离近站点，病态影响愈大；因而在观测时，应尽量使观测弧段与近站点对称（此时μ值较大），这是提高短弧定轨的一种有效途径．
The ill-conditron analysis and error analysis for the known initial orbit algorithms are made in this paper. Our results indicate that the influence of ill-condition on the accuracy of the known initial orbit comes from the deviation of normal equation coefficients due to observation errors. In the coefficient determinant, the greater △μ /μ is, the lower the accuracy of orbit determination will be. The known methods will fail if μ is suppressed by △μ. Besides, the simulated results show that the value of μ or μ strongly depend on the space position of observation arc. When the mid point of observation arc is the nearest point to station, μ has a maximum, △μ / μ is small, and a high accuracy of orbit determination can be obtained. When the observation are inclines to one side of the nearest point, μ is small, △μ / μ is great and the accuracy of orbit determination is low. The farther observation are leaves from the nearest point, the greater influence of ill-conditions. It is a good way for improving the accuracy of initial orbit determination to keep will be observation arc symmetric to the nearest point.
出处
《天文学报》
CSCD
北大核心
1997年第3期288-296,共9页
Acta Astronomica Sinica
基金
国家自然科学基金项目
