摘要
讨论了平方根滤波、卡尔曼平滑和双向滤波对卡尔曼滤波的改进,采用平方根滤波/平滑/双向滤波3种算法计算了两颗GRACE卫星轨道。采用GRACE(gravity recovery and climate experiment)卫星的星载GPS观测数据进行了定轨计算,并用JPL提供的GRACE卫星轨道及KBR(K-band ranging system)观测数据进行了外部检验。
In the paper, the improvements of square root filtering, Kalman smoothing and bidirectional filtering on Kalman filtering is discussed. Two GRACE satellites orbits are computed by using square root filtering/smoothing/bidirectional filtering. The results are compared with the orbits provided by JPL and independently validated with k-band ranging （KBR） data. By comparison and analysis, we find that POD using fixed-interval Kalman smoothing can improve the accuracy of square root extended Kalman filtering （SR-EKF） result at the beginning of the data arc. The result of bidirectional filtering can not only improve the accuracy of SR-EKF result at the beginning of the data arc evidently, but also improve the accuracy of orbits after steady of SR-EKF. We also find that the orbits of GRACE which computed using SR-EKF are at a level of about 20 cm in 3-Dimension position and about 10 cm in radial（R）, transverse（T） and normal（N） direction respectively. The result of fixed-interval Kalman smoothing can get 15 cm in 3-Dimension position and about 8 cm in radial（R）, transverse（T） and normal（N） direction respectively. The result of bidirectional filtering can get 10 cm in 3-Dimension position and about 5 cm in radial（R）, transverse（T） and normal（N） direction respectively.
出处
《武汉大学学报（信息科学版）》
EI
CSCD
北大核心
2009年第10期1176-1180,共5页
Geomatics and Information Science of Wuhan University
基金
国家自然科学基金资助项目(40474001
40604003)
关键词
GPS
卫星定轨
平方根
滤波
平滑
GPS
satellite orbit determination
square root
filter
smoothing
