A new scalloping filter algorithm for scansar images

Due to its specific way of scanning over multiple sub-swaths of a radar image, a ScanSAR (scanning synthetic aperture radar) cannot sample Doppler histories continuously like a regular SAR in stripmap mode. This can cause an artifact known as azimuthal scalloping, a wave-like modulation of the image intensity in azimuth direction. Although the problem is theoretically understood, many ScanSAR images of ocean scenes continue to exhibit scalloping. This hampers their use for applications such as wave and wind retrievals. We have developed an efficient descalloping algorithm that can be applied to such images as a post-processing tool. We describe how it works and show examples.