Application of Smoothing Algorithm in SINS/GPS Integrated System for Airborne SAR Real-time Motion Compensation

Considering the urgent need of high precision motion parameter for SAR motion compensation in real-time, a motion compensation scheme using the Strapdown Inertial Navigation System/Global Positioning System (SINS/GPS) integrated system based on Rauch-Tung-Striebel (R-T-S) smoothing method is proposed. In this scheme, the Kalman filtering is done firstly and based on this, the backward smoothing iteration is performed for correcting the filters results during each synthetic aperture moment. The results of numerical simulation and flight-test data processing show that the scheme can effectively improve the precision of estimates of the motion parameter in the synthetic aperture moment.