机载SAR反投影图像自聚焦处理方法
收稿日期: 2013-12-24
修回日期: 2014-07-27
网络出版日期: 2014-08-15
基金资助
中国博士后科学基金(2014M551630);江苏省博士后科研资助计划(1302089B);江苏省高校自然科学研究项目(14KJ B510024);中央高校基本科研业务费(NJ20140008);南京航空航天大学基本科研业务费(NS2013023); 毫米波国家重点实验室开放课题(K201506)
Autofocus Method of Airborne SAR Imagery Reconstructed via Backprojection
Received date: 2013-12-24
Revised date: 2014-07-27
Online published: 2014-08-15
Supported by
China Postdoctoral Science Foundation (2014M551630); Jiangsu Planned Projects for Postdoctoral Research Funds (1302089B); Natural Science Foundation of the Jiangsu Higher Education Institutions of China(14KJB510024); Fundamental Research Funds for the Central Universities (NJ20140008); NUAA Fundamental Research Funds(NS2013023); Open Reasearch Program of State Key Laboratory of Millimeter Waves (K201506)
王昕 , 朱岱寅 , 蒋锐 . 机载SAR反投影图像自聚焦处理方法[J]. 航空学报, 2014 , 35(11) : 3074 -3081 . DOI: 10.7527/S1000-6893.2014.0168
Backprojection algorithm (BPA) is a classic time domain synthetic aperture radar(SAR) imaging method. Since the imagery reconstructed via BPA is derived via interpolation and accumulation of SAR phase history data, defocus due to motion error will along variant directions and hence traditional autofocus methods cannot be applied directly. To solve this problem, a novel autofocus method for BPA reconstructed imagery is proposed in this paper. Based on the analysis of motion phase error and range migration of BPA processed data, imaging grid is modified to eliminate the space variance of defocus in imagery. The reconstructed SAR imageries after modification can be motion compensated by the phase gradient autofocus (PGA) algorithm in low and moderate resolution cases. Point target simulation results and real data results validate this algorithm.
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