Image Defocus in an Airborne UWB VHR Microwave Photonic SAR: Analysis and Compensation Xu, Weidi ; Wang, Bingnan ; Xiang, Maosheng ; Li, Ruoming ; Li, Wangzhe Abstract Publication: IEEE Transactions on Geoscience and Remote Sensing Pub Date: 2022 DOI: 10.1109/TGRS.2021.3108571 Bibcode: 2022ITGRS..6008571X