Abstract:The Fourier Transform Pairs (FTP) between the image domain and its corresponding range-compressed phase history domain is critical for autofocus. Different from the frequency-domain algorithms, this requirement of FTP is both complicated and difficult to be met in the time-domain algorithms. For a swift and effective reconstruction and autofocus processing of imagery created by the time-domain algorithm, the necessary improvement and optimization in the Fast Factorized Back-Projection (FFBP) is performed, presenting an Improved FFBP (IFFBP) algorithm further. Through the pseudo-polar coordinate system, the IFFBP is able to pave the way for autofocus application. Also, in view of the practical requirements for data processing, the IFFBP uses a moderate-accuracy Inertial Measurement Unit (IMU) to achieve a coarse compensation,and combines with the Phase Gradient Autofocus (PGA) to make a fine compensation. Finally, the simulation results and the collected data sets verify and validate the proposed approach.
李浩林, 陈露露, 张磊, 邢孟道, 保铮. 快速分解后向投影SAR成像的自聚焦算法研究[J]. 电子与信息学报, 2014, 36(4): 938-945.
Li Hao-Lin, Chen Lu-Lu, Zhang Lei, Xing Meng-Dao, Bao Zheng. Study of Autofocus Method for SAR Imagery Created by Fast Factorized Backprojection. , 2014, 36(4): 938-945.