Application of Stochastic Model in GPS Satellite Clock Estimation

Abstract:

Satellite clock affects the positioning accuracy the most. Based on a study of the pseudorange observation accuracy of different receivers and corresponding phase variance， a reasonable stochastic model was established. The GPS data from 56 IGS stations were connected to estimate the satellite clock and to analyze the positioning performance. The estimation results of the satellite clock based on this method prove to the positioning accuracy improve about 5% in comparison with the traditional clock estimation method. The stochastic model was employed to the positioning solution using the IGS satellite clock. Within 10 stations， the convergence time and positioning accuracy of 7 stations improved significantly. Compared with the traditional fixed weight method， the convergence time improves about 78% the most， and the positioning accuracy improves about 86.55% the most.

Key words:satellite clock;precise point positioning (PPP);stochastic model