Multi-Look Radiometric Correction of SAR Images

Abstract

Deviations of the aircraft trajectory and instabilities of the aircraft orientation lead to non-uniform illumination of the ground by the antenna beam and, as a result, to radiometric errors in radar images obtained with airborne synthetic aperture radars (SAR). The clutter-lock technique is commonly used to avoid the radiometric errors. However, this approach leads to strong geometric distortions in SAR images in the case of fast and significant instabilities of antenna orientation. Here we propose a multilook radiometric correction technique which can be used instead of the clutter-lock. The proposed approach has been tested by using a Ku-band airborne SAR system installed onboard a light-weight aircraft.