GPS/INS integrated measurement system on Earth-circling spacecraft

This paper proposes GPS/INS integrated to implement the positioning and the attitude determination of the Earth-circling spacecraft. Observability analysis shows that the integration system, in which only GPS pseudo-range and delta pseudo-range are the observable, cannot assure favorable observability of the attitude error angles. The GPS carrier phase observable can be introduced to enhance the reliability and the precision in attitude determination. Here receiver autonomous integrity monitoring (RAIM) is used to eliminate the anomalous data, so as to get an improved adaptive filtering algorithm, which has a faster convergent speed and better stability than the conventional Kalman filtering algorithm. Finally, simulations are given to verify the effectiveness of the algorithm