SAR real time motion compensation: average cancellation method for aircraft

Abstract

Effective motion compensation is the key for achieving high quality SAR images. A frequency domain method which is based on an analysis of the azimuth spectrum of SAR raw data to extract aircraft's motion-error, has the advantage of having the ability to operate without accelerometer and INS. However, an antenna with a wide azimuth beam is required. Furthermore,its accuracy depends heavily on the contrast of the ground reflectivity function. A new method based on the time domain approach is presented. Compared with the existing method, the new approach not only has all the mentioned features, but also the advantages of low computation requirement as well as the wide-band motion-error extraction capability. Furthermore, it relaxes some requirements on azimuth antenna beamwidth as well as the ground reflectivity function contrast.<>