Research On Adaptive Processing And Reference Of Autonomous Orbit Determination For Navigation Constellation

It is one of the hottest issues that autonomous orbit determination of navigation constellation based on inter-satellite measurement. In this paper, we mainly focus on adaptive processing and reference of autonomous orbit determination for navigation constellation.(1) Research on the distributed filtering algorithm of navigation satellite constellation. The orbit determination model of navigation satellite is a typical nonlinear system. Solving the distributed satellite orbit model based on the extended Kalman filter. A distributed Kalman filtering algorithm is derived and data processing procedure is presented. Finally, this filtering algorithm is proved valid by simulation scenario.(2) Considering gross error in inter-satellite measurement and the dynamic models in the orbit determination of satellite, this paper analyzes several common equivalent weight function based on robust M-estimation theory, by giving several robust extended Kalman filtering schemes and analyzing orbited effects of several robust schemes. The IGG scheme is an optimal method, which is suitable for autonomous orbit determination for navigation constellation based on inter-satellite measurement. On this basis, this paper be combined with the adaptive filter theory, proposed robust adaptive Kalman filtering method of orbit determination. Comparing with extended Kalman filter and robust extended Kalman filter, robust adaptive Kalman filtering can not only resist gross error in inter-satellite measurement, but also balance the contribution of dynamic model and inter-satellite measurement value to this filter. Thus, it can improve the precision of the orbit determination.(3) The orbit determination of navigation satellite network based on inter-satellite measurement is one solution of free network. If orbit parameters were estimated by the least square criterion, it would be not optimal and unique solutions. According to the theory and method of adjustment, the essence of this problem is the lack of datum. For this problem, this paper from the view of mathematics, analyzes the causes of free network rank deficiency, and proposes orbit determination algorithm based on a constellation of centralized virtual reference. The algorithm regards orbit dynamics information as prior information for the satellite network, adding minimum norm constraint besides the least square criterion. The simulation results showed that the user range error (URE) of any satellite is less than 0.8 meters, and mean URE of the satellite network is less than 0.5 meters after five days autonomy operation, which verified the efficiency of the method.