Carrier phase/SINS integrated navigation for spacecraft on high earth orbit

Because of the fewer available satellites and the greater wastage of signal on space link, the measurement accuracy is lower using pseudo-distance. The method of autonomous navigation using carrier phase of global navigation satellite system(GNSS) and strapdown inertial navigation system (SINS) was presented for the high earth orbit automotive spacecraft. The float solutions of initial integer ambiguity were used as states variable in this method, and the nonlinear filter was established by square-root unscented Kalman filter (SRUKF). The method of cycle slips faults detection and isolation was presented based on the intersections of the float solutions. The method of integrated navigation makes full use of the high measurement accuracy of carrier phase and slowly varying characteristic of systematic errors, and it can increase the reliability and the precision of the navigation system.