基于SGP4模型与多普勒频移的改进定轨方法  

Improved orbit determination based on SGP4 model and Doppler shifts

作　　者：陆正亮 张翔[1] 刘洋[1] 廖文和[1] 

机构地区：[1]南京理工大学机械工程学院,江苏南京210094

出　　处：《系统工程与电子技术》2016年第6期1360-1366,共7页Systems Engineering and Electronics

基　　金：欧盟第七科研框架计划QB50项目(284427);教育部科技发展中心博士点基金(20133219120030);江苏省高校优势学科建设项目资助课题

摘　　要：立方体卫星广泛使用两行根数(two-line element,TLE)结合SGP4模型作为定轨的唯一或是备份手段。针对SGP4模型长期预报误差积累的问题,分析了模型的误差来源及分布情况,提出两种利用地面观测站测量多普勒频移提高定轨精度的方法。一种方法直接修正大气阻力项系数,结果表明能大幅减小速度方向上的预报误差,将预报10天的位置精度提高到4km以内。另一种方法将已知的两行根数更新为卫星过境时刻的两行根数,然后修正纬度幅角,修正后短期预报误差能基本消除但长期精度不如前一种方法。通过对在轨立方体卫星的实际测量也验证了上述的结论。CubeSats always choose two-line element （TLE） in conjunction with the SGP4 model to deter- mine the orbit, or as a backup method. To settle the problem that the propagation error accumulates over time, the source and distribution of the errors are analyzed and two improved approaches are proposed by using Doppler shifts. One is to directly correct the drag coefficient and results show a significantly decrease in in-track orientation error. The position difference is improved to 4 km in 10 days. The other approach is to update the TLE epoch time to the pass time firstly, and then correct the argument of the latitude. Simulation results indicate that the position error can be almost removed in a short time but the long time performance is worse than the first method. The conclusion is also verified by actual measurements from the in-orbit CubeSats.

关 键 词：立方体卫星 两行根数 SGP4模型 多普勒频移 

分 类 号：V448.232[航空宇航科学与技术—飞行器设计]