Study on BeiDou Navigation Satellite Precise Orbit Determination Based on the Extended Kalman Filtering

In order to the study of BeiDou navigation satellite system (BDS) precise orbit determination, a suit of satellite precise orbit determination software named Orbit Study is developed under VC6.0 platform. Object-oriented programming ideas are used. The implementation of each module is carried out by the corresponding c++ class. This software currently processes undifferenced phase and pseudorange measurements. The Extended Kalman Filter (EKF) is used to estimate parameters. It can satisfy the need of post or real time orbit determination. Firstly, the basic modules of Orbit Study are introduced. The data management mode and the optimization algorithm of improving the computational efficiency are also been introduced in the first part. Secondly, the observation model, dynamic model and EKF orbit determination process are introduced. Thirdly, BDS orbit determination experiment is processed based on the observation of Compass Experimental Test Service network (CETS). Two types for comparison for BDS orbit determination accuracy are used, which are inner and outer consistency test. Although the results show that the accuracy of Orbit Study is 10 cm worse than PANDA in radial direction, it has orbit determination ability of BDS preliminary. At last, the reasons of this result are analyzed and the next plans are proposed.