Inter-satellite Real-time Relative Positioning Method Based on Augmented

The real-time inter-satellite relative positioning method based on augmented GPS can achieve the level of centimeter in case of having the orbit dynamic model. In view of its difficulty of full-filing the high-precision requirement of orbit dynamic model currently, this paper proposes a new high-precision real-time relative positioning method which uses tripe-difference functions of GPS to get the time transform matrix of state vector, then uses UKF (Unsented Kalman Filter) to estimate the inter-satellite real-time relative positions. Simulation results show that comparing the precision of decimeter level of the relative positioning using the usual sequent point estimation method, the new method can achieve the relative positioning precision of centimeter level when the inter-satellite distance is less than five kilometers.