Improved RDM for SAR autofocus processing

Reflectivity displacement method (RDM) is a classical algorithm of synthetic aperture radar (SAR) autofocus processing, whose performance degenerates with low contrast of the scene. This paper proposes an improved RDM for SAR auto focusing. Based on the relationship between the Doppler rate and the range, the proposed method can adoptively overcome the effect of the low contrast on the Doppler rate estimation and obtain fine autofocusing results. The experiments with real SAR data are used to show the effectivity of the proposed method.