共查询到19条相似文献,搜索用时 75 毫秒
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常规SAR成像,平台沿直线飞行,形成直线型合成孔径,仅能获取2维图像,即3维空间中的观测场景在斜距-方位平面的2维投影,图像具有叠掩、透视缩短、阴影等畸变现象。SAR 3维成像突破了斜距-方位2维频率信息获取,能够获取第3维频率信息,实现3维分辨,可获得观测场景的散射中心在3维空间中的分布,从而解决叠掩问题,消除透视缩短、顶底倒置等几何形变现象,更直观地描述客观场景,已成为国际研究热点。该文介绍SAR 3维成像的概念和主要观测模式,分析该领域国内外研究现状和进展,重点阐述作者所在研究团队的SAR 3维成像研究进展,最后对SAR 3维成像技术进行总结和展望。 相似文献
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基于局部最小生成树的干涉SAR二维相位展开 总被引:3,自引:1,他引:3
二维相位展开是干涉SAR数据处理中的关键步骤之一.该文在分支优化模型的基础上提出一种基于局部最小生成树的干涉SAR二维相位展开算法.该算法克服了经典的Goldstein算法中残余点之间重复连接形成闭合区域的缺点.同时由于质量图的使用,优化了残余点的连接,局部最小化了分支的总长度,实验结果证实了该算法的有效性. 相似文献
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速度聚束调制是浅海水下地形合成孔径雷达(SAR)成像的关键理论,文中对其进行了深入研究。首先从多普勒频移观点论述了速度聚束调制,然后从海浪运动观点,对速度聚束调制重新进行理论推导,指出了两种观点得到结果的异同。最后由理论推导,证明了雷达参数之间需要满足一定的约束条件,才能保证速度聚束调制的准确性。本研究为SAR海洋遥感系统的设计提供了参考。 相似文献
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重复飞行机载干涉SAR的实验研究 总被引:1,自引:1,他引:0
该文在介绍重复飞行机械干涉SAR基本原理之后,分析了在L波段机载SAR(CASSAR)飞行实验中的航线控制方式和航线偏差对干涉成像的影响,研究了基于INS/GPS组合导航系统的运动补偿方法,提出了利用配准点拟合投影函数方法解决非平行基线的去相干性问题,通过高程反演,获得了观测地区局部的三维地形图。 相似文献
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本文以干涉SAR相位展开的残差理论为基础对经典的相位展开算法分支阻断算法进行了详细深入的理论分析和解析.对长期以来由于原始文献的简节或由对残差现象的不充分理解而造成的对Goldstein的分支阻断算法的错误理解和结论进行了说明和纠正.进而,引入了统一接地处理与最近邻偶极子对残差预处理步骤,大幅度降低了分支的长度及展开相位解平面中的不连续区域的个数.最后讨论了分支阻断算法的性能和特点,及其在分离残差方面的普遍意义.实际X-SAR数据的相位展开处理给出了正确而详尽的结果. 相似文献
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建立了包含海表面高度和速度聚束的交叉轨迹干涉合成孔径雷达(AcrossTrack Interferometric Synthetic Aperture Radar,XTI-SAR)涌浪干涉相位模型,得到了涌浪成像的解析表达式.进一步研究了XTI-SAR沿方位向传播的涌浪成像机制.定义二次谐波振幅与基波振幅比率来表征成像非线性,通过比较XTI-SAR和沿轨迹干涉合成孔径雷达(Along-Track Interferometric Synthetic Aperture Radar,ATI-SAR)相位的二阶调和分量,分析不同海况和干涉SAR参数情况下的数值模拟,结果表明:当速度聚束弱时,XTI-SAR相位比ATI-SAR相位具有较强的非线性,ATI-SAR比XTI-SAR更适合测量海浪.当速度聚束强时,XTI-SAR相位比ATI-SAR相位具有较弱的非线性,XTI-SAR比ATI-SAR更适合测量海浪. 相似文献
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Veneziani N. Bovenga F. Refice A. 《Multidimensional Systems and Signal Processing》2003,14(1-3):183-205
Because of possible multiple solutions allowed, the unwrapping of interferometric fringe patterns in the spatial domain is an ill-posed problem which needs some a priori knowledge of the ground morphology for the solution of ambiguities. This is especially true for interferometric SAR (Synthetic Aperture Radar) data. In this paper we propose a different approach to InSAR processing for retrieving the height of ground points independently from each other, unlike most conventional phase unwrapping procedures, which operate in the spatial domain. The basic idea is to repeat raw data focusing by using range sub-bands centered at different frequencies, in order to find a point history of the interferometric phase variation vs. frequency. We introduce the general framework of the method together with considerations on the theoretical limits of applicability, then we report results of our simulations related to a wide-band SAR system. We show that, under certain conditions, height values can be retrieved over a network of coherent and strong scatterers, even when enclosed into low-coherence areas. 相似文献
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Lin Zhiping Zeng Yonghong Bi Guoan Yeo Jocelyn 《Multidimensional Systems and Signal Processing》2003,14(1-3):119-137
We first show that for some kinds of signals a bandwidth and time duration reduction technique can be used to simulate waveform distortions caused by moving targets, that is, it is correct to measure the waveform distortions at very large TB with relatively small by reducing TB and increasing while keeping TB unchanged, where T is the duration of the transmitted signal, B is the bandwidth and is the relative speed of targets. We then study the waveform distortions in SAR signals caused by moving antenna. Based on the bandwidth and time duration reduction technique, a lot of time and memory are saved in simulations. We then confirm by simulations that waveform distortions do pose problems when processing very large bandwidth and long duration SAR data using conventional SAR processing methods. Finally we propose the concepts of wideband and narrowband processing of SAR data. Models are set up for wideband and narrowband SAR data processing, and new methods are presented for reconstructing targets using the proposed models. Simulations show that the methods can improve the quality of the simulated SAR images. 相似文献