A subband algorithm for real-time autofocusing of SAR images

Presents an autofocusing algorithm for real-time synthetic aperture radar (SAR) processing. The algorithm is based on the fact that time shifts between subband SAR images represent the phase errors due to motion errors during the flight of the radar platform. The subband SAR images are generated by subband decomposition of the high-resolution high-contrast area of a complex SAR image. The successive steps of the subband algorithm have low complexity compared to conventional autofocus algorithms and can be implemented efficiently in hardware.