基于压缩感知的分布式SAR成像

发布时间：2018-08-02 17:34

【摘要】：现代雷达技术经过了多年的发展与积累，涌现出了很多典型雷达系统，，SAR雷达系统由于自身的诸多优势从一开始提出就受到专家学者的重视，在成像方面已经可以达到亚米级别的分辨性能，并可以成功实现对于观测场景中的移动目标的成像定位。本文机载分布式SAR作为研究背景，研究了机载SAR中的杂波抑制和分布式静止和移动目标的成像定位，在这些算法中，都加入了压缩感知技术，通过此技术降低对于数据数量的要求，有效的减轻了成像对于雷达系统硬件设计、数据传输等方面的压力。本文重点介绍了SAR成像中的几个算法，主要内容有： 1.介绍了传统的SAR成像系统的成像以及目标检测原理，文章后面会研究对于移动目标的成像，因此也分析了物体速度对于传统成像算法的影响，并且给出了此部分的实验来验证这些影响。 2.重点分析了分布式机载SAR接收回波中的杂波的特性，研究了STAP在此平台上的应用可行性，并且给出了具体的处理过程步骤。由于在实际的STAP过程中，进行CCM的估值的过程就需要拥有来自场景足够数目的均匀训练样本，但是实际场景并不能提供相应数目，考虑到压缩感知技术在此方面的优势，成功的引入了该技术，从而降低了算法对样本数的要求。 3.研究了利用了压缩感知方法的分布式的SAR成像技术，成像对象不仅仅局限于静止物体，也对移动目标成功成像。提出了基于CS技术的分布式静止、移动目标成像算法，结合了偏移相位与压缩感知技术的优势，成功减轻了单个雷达天线在方位、距离上的采样率，对于硬件设计是一个较大的解放。最后通过多个实验，验证了算法的在不同欠采样率、信噪比等方面的性能，验证了算法有效性。
[Abstract]:After years of development and accumulation of modern radar technology, a lot of typical radar systems have emerged. In the imaging aspect, the resolution of sub-meter level can be achieved, and the imaging location of moving targets in the observation scene can be successfully realized. In this paper, airborne distributed SAR is used as the research background, clutter suppression in airborne SAR and imaging localization of distributed static and moving targets are studied. In these algorithms, compression sensing technology is added to these algorithms. Through this technique, the requirement of data quantity is reduced, and the pressure of imaging on radar system hardware design, data transmission and so on is effectively reduced. Several algorithms in SAR imaging are introduced in this paper. The main contents are as follows: 1. This paper introduces the imaging and target detection principle of traditional SAR imaging system. In the end, the paper studies the imaging of moving target, so the influence of velocity on the traditional imaging algorithm is also analyzed. And this part of the experiment is given to verify these effects. 2. 2. The characteristics of clutter in the distributed airborne SAR are analyzed, the feasibility of the application of STAP on this platform is studied, and the process steps are given. In the actual STAP process, the process of CCM estimation needs to have a sufficient number of uniform training samples from the scene, but the actual scene can not provide the corresponding number, considering the advantages of compression sensing technology in this respect. Successful introduction of this technology, thus reducing the algorithm for the number of samples. 3. A distributed SAR imaging technique using compression sensing is studied. The imaging object is not only confined to the stationary object, but also successfully imaged to the moving target. A distributed static and moving target imaging algorithm based on CS technology is proposed, which combines the advantages of offset phase and compression sensing technology, and successfully reduces the sampling rate of a single radar antenna in azimuth and range. For hardware design is a great liberation. Finally, several experiments are carried out to verify the performance of the algorithm in different under-sampling rates and signal-to-noise ratio (SNR), and the effectiveness of the algorithm is verified.
【学位授予单位】：哈尔滨工业大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TN957.52

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