Azimuth Ambiguities Suppression Using Group Sparsity and Nonconvex Regularization for Sliding Spotlight Mode: Results on QILU-1 SAR Data.

High resolution and high quality are now the requirements in synthetic aperture radar (SAR) research. The sliding spotlight mode can obtain high azimuth resolution because of its large azimuth bandwidth. Group sparse penalty can effectively suppress azimuth ambiguities to improve image quality. Generalized mini-max concave (GMC) penalty is a kind of nonconvex penalty, which is widely used in SAR imaging. In this paper, a novel sliding spotlight SAR imaging method based on group sparsity and nonconvex regularization is proposed. Compared with matched filtering method, the proposed method can suppress noise and azimuth ambiguities. Both simulations and Qilu-1(QL-1) real SAR data experiments verify the effectiveness of the proposed method.