Research On Real-time Orbit Determination For Navigation Satellite

For solving the problem of discontinuity caused by maneuvers in the process of ordinaryprecise orbit determination, main focus is payed on the method of real-time orbit determinationof navigation satellite during orbit maneuvers and restore. The purpose is to gain real-timesatellite orbit in the whole process, to assure satellite navigation system to be fine and stable andto improve system availability. China’s satellite navigation system is establishing, it is veryimportant to realize the technology of real-time orbit determination of navigation satellite duringorbit maneuvers and restore, it can improve the overall level of China’s satellite navigation andpositioning.The paper aims at realizing the goal of real-time orbit determination of navigation satellite,and focuses on the key technologies of the mathematical model and algorithm, programming andthe other aspects more acomprehensively, then analyzed the results compared with interpolationresults of IGS precise ephemeris. The main works and contributions as follows:1. The paper introduces the observation and the error correction for the real-time orbitdetermination. According to the demand of real-time orbit determination, it chooses the betterobservation for the orbit determination. Through real observation data, the effect of errorcorrection is discussed.2. The paper studies the geometric method of real-time orbit determination. A method ofgetting the observation which is sent in the same time is given, geometric real-time orbitdetermination of navigation satellite is designed and realized. Through real observation data, thecorrectness of the orbit determination method is verified, the different proceeding strategies onthe precision of orbit determination are analyzed.3. The paper studies the dynamic orbit determination method based on the geometric greatly.The advantage and disadvantage of geometric orbit determination and dynamic orbitdetermination is dicussed, combining with the thought of dynamic smoothing, and consideringthe advantage of geometric method and dynamic method, the dynamic orbit determinationmethod based on the geometric method is turned up. The result of geometric orbit determinationis used as measurement of the dynamic orbit determination. In fact, it is a geometric dynamicalmethod which constraints the track of geometric method through dynamic equation, smooth theresults of geometric method. Precision of this method is higher than geometric method, theresults are more stable.Through real observation data, the correctness of this method is verified,the orbit determination results of the method and geometric method are compared, the mainfactors which affect the dynamic orbit determination method based on the geometric method are analyzed.4. The paper studies the adaptive Kalman filter real-time orbit determination. The influenceof the adaptive factor and break-off of the measurement in AKF real-time orbit determination areanalyzed.