Airborne attitude/ground target location determinations using unscented Kalman filter

An innovative technique, utilizing solely a GPS pseudorange receiver and an off-the-shelf CCD camera, is presented to simultaneously identify the aircraft attitude and the location of a ground target within the field of view of the camera. The integration of unscented Kalman filter(UKF) equation and the orientation representation using quaternion in the formulation of system dynamics and measurement process makes UKF outperform the conventional extended Kalman filter(EKF) processing in the following aspects: fast convergence, averaging operation instead of linearization, and plausibility in various industrial/military applications. Due to the inclusions of aforementioned two kinds of sensors, the cost of the entire system is dramatically reduced. No singular position is encountered owning to the introduction of quaternion algebra in rotation formulation. Simulations are conducted; both attitude estimation and ground target positioning errors are computed via UKF; and the beauty of fast convergence rate of UKF is witnessed.