A new motion error extraction method based on RCM trajectory from raw data for motion compensation

The quality of Synthetic Aperture Radar image is affected by the deviation of radar platforms from the nominal straight line which is usually measured based on hardware such as Inertial Measurement Unit and Global Position System with high accuracy. Because of limited budget, many SAR systems cannot carry those expensive equipments. Based on the 3-D Geometry model of the motion error analysis, a new method of aircraft motion error extraction from the SAR raw data is proposed in this paper. To apply this estimation method, we first extract the range cell migration trajectories of strong targets from range compressed data before range cell migration correction procedure. Second, with the help of pseudo-inverse method, the motion errors in line of sight direction will be calculated using the extracted trajectories. Finally, experiments on simulated data validate this proposed method.