基于误差发散规律的低轨卫星大气阻力系数计算方法  

The Method for Calculating Atmospheric Drag Coefficient Based on the Characteristics of Along-track Error in LEO Orbit Prediction

作　　者：汪宏波[1,2,3] 赵长印[1,2] 柳仲贵[4] 张伟[1,2] 

机构地区：[1]中国科学院紫金山天文台,南京210008 [2]中国科学院空间目标与碎片观测重点实验室,南京210008 [3]宇航动力学国家重点实验室,西安710043 [4]北京跟踪与通信技术研究所,北京100094

出　　处：《天文学报》2016年第4期447-460,共14页Acta Astronomica Sinica

基　　金：宇航动力学国家重点实验室开放基金资助

摘　　要：低轨卫星轨道预报精度受到大气模型和大气阻力系数精度的制约,给一些高精度的空间和航天任务带来不利影响.提出了一种基于沿迹方向误差发散规律的大气阻力系数计算新方法.首先通过理论推导给出低轨卫星轨道预报中沿迹误差发散的分析表达式,定量描述初值误差和模型误差对沿迹误差的综合影响;提出利用定轨段的基本信息,优选预报段所采用的阻力系数,抑制沿迹误差的发散速率,从而降低沿迹方向预报误差的最大值,提高短期预报精度.以400 km附近的GRACE-A卫星的全弧段星载GPS高精度资料为基础,检验了方法的精度和成功率.结果表明:相对于传统的定轨预报方法,新方法能提高24 h短期预报精度约45%,成功率约71%,总体有效率约86%;方法对低、中、高等3种太阳辐射水平均有效,对于中低等级的地磁扰动也有效,具备较好的应用价值.The errors of atmosphere density model and drag coefficient are the major factors to restrain the accuracy of orbit prediction for the LEO （Low Earth Orbit） objects, which would affect unfavorably the space missions that need a high-precision orbit. This paper brings out a new method for calculating the drag coefficient based on the divergence laws of prediction error＇s along-track component. Firstly, we deduce the expression of along-track error in LEO＇s orbit prediction, revealing the comprehensive effect of the initial orbit and model＇s errors in the along-track direction. According to this expression, we work out a suitable drag coefficient adopted in prediction step on the basis of some certain information from orbit determination step, which will limit the increasing rate of along-track error and reduce the largest error in this direction, then achieving the goal of improving the accuracy of orbit prediction. In order to verify the method＇s accuracy and successful rate in the practice of orbit prediction, we use the full-arcs high precision position data from the GPS receiver on GRACE-A. The result shows that this new method can significantly improve the accuracy of prediction by about 45%, achieving a successful rate of about 71% and an effective rate of about 86%, with respect to classical method which uses the fitted drag coefficient directly from orbit determination step. Furthermore, the new method shows a preferable application value, because it is effective for low, moderate, and high solar radiation levels, as well as some quiet and moderate geomagnetic activity condition.

关 键 词：天体力学:轨道计算和定轨 方法:数值 高层大气阻力 

分 类 号：P135[天文地球—天体力学]