Research on autonomous orbit determination for earth-moon constellation based on adaptive EKF

Abstract

In order to resolve the unobservable problem when only the inter-satellite range of the Earth constellation is utilized for autonomous orbit determination, Lagrange satellites related measurements can be introduced, yielding the method of autonomous orbit determination for earth-moon constellation. For such an orbit determination system, after the dynamic model and the observation model are established, the main issue is that the prior information of the system noise is difficult to be obtained accurately, resulting as significant errors of the estimated orbits. Thus, in this paper, an improved adaptive Extended Kalman Filter (EKF) based on Sage-Husa algorithm is proposed to achieve a high-precision, long-term orbit determination system. Simulation experiments are carried out to compare it with recent algorithms. And the results validate the effectiveness of solving the unobservable problem, and the significant accuracy improvements.