The Geometric-Distortion Correction Algorithm for Circular-Scanning SAR Imaging

The image formation scheme for circular-scanning synthetic aperture radar includes generating a set of focused subimages and the followed mosaiking processing. However, due to the particular acquisition geometry and irregular motion of the radar platform, the inevitable geometric distortions in the subimages are necessary to be corrected. In this letter, a 2-D geometric-distortion correction algorithm based on projection transformation between the scatterers and the images is presented, in condition of focusing the subimages using a linear range-Doppler algorithm. The point target simulation and real circular-scanning data implementation results are provided to demonstrate the validity of the proposed method.