The use of CLEAN processing for passive SAR image creation

The paper presents the concept of the use of CLEAN processing for strong direct signal removal in passive SAR systems. The CLEAN algorithm proposed has been successfully verified during several measurement campaigns. During the trials the passive SAR receiver was placed at ground level, and different SAR satellites (e.g. EnviSAT, TerraSAR-X) were used as illuminators of opportunity. Almost all SAR radars use the chirp sounding signal, and the presence of a direct signal in the reference channel limits the quality of the image. The removal of the strong direct signal leads to improvement of the image at a short distance from the receiver, which is the case considered in this paper.