引用本文: | 李悦丽,梁甸农,黎向阳.一种改进方位向非线性CS大斜视角SAR成像算法[J].国防科技大学学报,2008,30(5):62-67.[点击复制] |
LI Yueli,LIANG Diannong,LI Xiangyang.A Refined Azimuth Nonlinear Chirp Scaling Algorithm for High Squint SAR Imaging[J].Journal of National University of Defense Technology,2008,30(5):62-67[点击复制] |
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一种改进方位向非线性CS大斜视角SAR成像算法 |
李悦丽, 梁甸农, 黎向阳 |
(国防科技大学 电子科学与工程学院,湖南 长沙 410073)
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摘要: |
大斜视角SAR成像时存在严重的距离走动现象,慢时域的距离走动校正在解决这一问题同时导致了聚焦深度问题。分析了二维频域解耦合后残余相位误差以及时域走动校正后的多普勒调频率误差,提出一种改进的方位向非线性CS算法,校正了三次以上距离迁徙带来的相位误差,同时采用改进非线性CS扰动方程补偿了随方位偏移量线性变化的调频率误差。仿真结果表明,改进算法的大斜视角大场景成像性能优于传统的高分辨大斜视角成像算法。 |
关键词: 大斜视SAR成像 时域距离走动校正 非线性CS |
DOI: |
投稿日期:2008-02-22 |
基金项目:国家部委基金资助项目(403030201) |
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A Refined Azimuth Nonlinear Chirp Scaling Algorithm for High Squint SAR Imaging |
LI Yueli, LIANG Diannong, LI Xiangyang |
(College of Electronic Science and Engineering, National Univ. of Defense Technology, Changsha 410073, China)
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Abstract: |
The range walk correction (RWC) in time domain can resolve range walk problem in high squint SAR imaging. However, the limit of focus depth exists. By analyzing the residual phase error after wave number decoupling and Doppler rate error caused by RWC, a refined azimuth non-linear chirp scaling (ANCS) algorithm is proposed. Phase error caused by the third order range migration is corrected and a nonlinear CS function is applied to equalize the targets Doppler rates before azimuth compression. Simulation results show that the refined ANCS algorithm has good performance. |
Keywords: high squint SAR imaging range walk correction in time domain non-linear chirp scaling |
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