Abstract:

This paper proposes an autonomous orbit determination algorithm combining the short-term dynamics orbit determination technique and the free-net pseudo-inverse adjustment using the measurements of the bi-directional distance measurement of the inter-satellite link (ISL) in a navigation constellation. This algorithm solves the problem of the rank defect because of the lack of the start information of the position calculation by pseudo-inverse adjustment, at the same time, sets up the state transition between the epoch steps using the orbit dynamics to solve the problem of the velocity calculation. The results show that, after running autonomously for 90 days, the satellites’ average user range error (URE) is less than 1m (2σ), better than the precision requirements of the autonomous operation of the navigation constellation, so the efficiency of the algorithm is verified.

Key words: Navigation constellation, Autonomous orbit determination, Network integrated adjustment, Dynamics, Pseudo inverse