A Navigation Method of The SAR Platform Combining The INS with The Scene-Matching Points

During flight the accurate navigation information of the aircraft is crucial to its safety in the situation without the Global Positioning System (GPS) signals. Focus on this issue, we propose a new navigation method of the Synthetic Aperture Radar (SAR) platform combining the Inertial Navigation System (INS) with the scene-matching points. Different from traditional methods, the statistical characteristics of errors of the positions and the pseudo-ranges of the scene-matching points are fully considered, and the new nonlinear equation of measurements is formed. The navigation information is obtained through the process of the Kalman Filter (KF) and the Extended Kalman Filter (EKF) in real time. In numerical experiments, the estimation of positions of the proposed method does not suffer from the accumulated errors, and can always provide smaller root-mean-square errors than the INS in different circumstances, which demonstrates the effectiveness and the superior performance of the proposed method.