Simultaneous estimations of ground target location and aircraft direction heading via image sequence and GPS carrier-phase data

An exquisite technique, using both dual GPS carrier-phase receivers' measurements and target image sequence, is proposed to attain the stationary target location on the ground as well as the aircraft heading. Direct solving of integer ambiguity in carrier-phase measurements is avoided, while the differences of the integer ambiguity numbers are incorporated in the states of the proposed statistical filter. The extended Kalman filter (EKF) is utilized to obtain the World Geodetic System-1984 (WGS-84) coordinate of the ground target without using any computation-intensive technique such as optical flow and measurement data error sensitive one like least-squares. A generic carrier-phase data processing technique is employed to calculate the attitude of the aircraft. The proposed filter's performance is verified by utilizing actual GPS carrier-phase measurement data.