Attitude determination with GPS based on predictive filter

The attitude determination with Global Position System (GPS) can be realized using a predictive filter based on the double difference of the carrier phase. Using the double difference of the carrier phase to determine the attitude is better than using the single-difference, which can improve accuracy of the attitude estimate. This algorithm is robust with respect to initial condition errors. It can converge to true attitude rapidly even if the numbers of baseline and sightline are few. The simulation shows that the attitude estimate based on this algorithm is almost similar to the attitude estimation based on the nonlinear least square algorithm, and robust to initial condition errors. When three baselines are used, during the maneuver of the vehicle, the baselines that are nearly orthogonal can estimate the attitude better than other frames of baselines.