Focus Improvement of Highly Squinted Data Based on Azimuth Nonlinear Scaling
Focus Improvement of Highly Squinted Data Based on Azimuth Nonlinear Scaling
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DOI：
10.1109/tgrs.2010.2102040
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发表时间：
2011-02
影响因子：
8.2
通讯作者：
Guangcai Sun;Xiuwei Jiang;M. Xing;Z. Qiao;Yirong Wu;Z. Bao
中科院分区：
文献类型：
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作者：
Guangcai Sun;Xiuwei Jiang;M. Xing;Z. Qiao;Yirong Wu;Z. Bao
将合成孔径技术应用于雷达信号处理，大大提高了雷达的信息能力。许多成像算法也被开发出来。然而，高斜视合成孔径雷达数据的高分辨率成像仍然是一个难题，因为距离偏移大，距离依赖于二次距离压缩项，二次距离压缩项相对较大且立方，对高分辨率具有高聚焦灵敏度。为了解决这一问题，本文研究了“斜视最小化”操作和方位角非线性啁啾缩放（CS）操作。在此基础上，提出了新的成像算法，分析了高斜视数据的特点和聚焦难点，讨论了ANCS的原理。我们还介绍了一种新的CS算法，数值算例表明，在70°s的斜视角度下，该算法可以达到0.1 m的分辨率。
Since synthetic aperture technology was employed in radar signal processing, the information capability of radar has greatly been enhanced. A lot of imaging algorithms have also been developed. However, the high-resolution imaging for highly squinted synthetic aperture radar data is still a difficult issue due to large range migration and strong range dependence on the secondary range compression term that is relatively large and cubic with high focusing sensibilities for high resolution. To accommodate for this problem, the "squint-minimization" operation and azimuth nonlinear chirp scaling (CS) (ANCS) operation are studied in this paper. On the basis of these operations, we propose new imaging algorithms and analyze the characteristic of highly squinted data and the difficulty in focusing these data as well as discussing the principle of ANCS. We also introduce a new CS algorithm, and numerical examples show that the proposed algorithm is able to achieve 0.1 m of resolution under a squint angle as large as 70°s.