Geo-location error correction for Synthetic Aperture Radar image

Spaceborne SAR (Synthetic Aperture Radar) image inherently contains geo-location errors which are caused by SAR image acquisition geometry, imaging mode, characteristics of reflectivity and image formation process. Since the geo-location error caused by SAR image acquisition geometry is inevitable, these errors are should be considered and corrected during the image formation process. In this paper, a geo-location error correction method is presented to analyze and correct the azimuth skew and ground range non-linearity error, and orientation error. This scheme does not require the aids of GCP and DEM, and instead directly extract the key correction parameters from the SAR raw data. Using RADARSAT-1 image, a simulation is performed to evaluate the proposed geo-location algorithm. To analyze the effect of proposed correction method, the corrected SAR images are compared with the reference image by RMSE values.