An Autofocus Cartesian Factorized Backprojection Algorithm for Spotlight Synthetic Aperture Radar Imaging Luo, Yin ; Zhao, Fengjun ; Li, Ning ; Zhang, Heng Abstract Publication: IEEE Geoscience and Remote Sensing Letters Pub Date: August 2018 DOI: 10.1109/LGRS.2018.2829483 Bibcode: 2018IGRSL..15.1244L