An algorithm for orbit determination of navigation satellites based on a ground beacon

As the precision of navigation satellites´ orbit determination is an important factor for the operation of the constellation navigation system, the beacon-based orbit determination algorithm of navigation satellites is discussed. A new strategy for orbit determination is proposed. In this strategy, signal is transmitted from a ground beacon station to navigation satellites. An extended kalman filter (EKF) is utilized for the orbit determination algorithm. The state process and the observation model are derived to establish the filter. Based on one ground beacon and three GPS satellites in different orbital planes, a one-day simulation is designed to verify the correctness of this algorithm. According to simulation results, error in estimate of position for any satellite is less than 3m, and error in estimate of clock bias for any satellite is less than 3ns.