MIMO分布式ISAR成像算法研究

发布时间：2018-12-08 12:32

【摘要】：随着传统逆合成孔径雷达(ISAR)成像技术的日趋成熟，其在一些复杂情况下的限制性条件也逐步提出。近年来，国内外研究者为解决传统ISAR成像的局限性问题进行了许多其他方面的研究。传统R-D成像算法的ISAR成像在实际应用中由于很多复杂的因素，导致可利用的成像积累时间短，因此有可能达不到所要求的方位向分辨率，影响成像效果进而影响目标识别。同时由于其成像所得到的图像是目标在目标与相对雷达间转轴垂直方向平面上的投影，是三维空间目标在二维平面的压缩，不能满足目标识别对空间三维目标进行三维成像的要求。本文主要针对能不同程度解决传统R-D成像算法局限性问题的其他算法进行研究并且取得不错的效果。本文首先对传统ISAR成像R-D算法的基本原理进行阐述，介绍了平稳运动目标的ISAR成像模型，雷达发射信号及回波处理方法，R-D算法距离向-方位向分辨率以及成像所需的不同运动补偿方法，通过仿真结果验证传统R-D算法理论的正确性及有效性。根据传统R-D算法的不同局限性问题，本文对以下两个方面进行研究。分布式ISAR成像算法是近年来新提出的一种ISAR成像技术。它采用多个收发雷达对同一目标发射一组射频信号，将不同雷达接收到的一维距离像进行选取、插值、组合，最后对组合后数据进行方位向多普勒分辨成像的方法来解决复杂情况下相干积累时间不足的限制。本文主要研究了几种不同情况下，分布式MIMO-ISAR成像算法对平稳运动目标的成像效果，理论以及仿真实验结果证明，，该方法在不同情况下都可以在达到方位向分辨率的前提下，缩短成像所需时间，或者在确保成像时间的前提下，提高成像的分辨率。这样缩短成像时间的方法扩大了ISAR成像的应用范围，提高了ISAR成像效果。干涉法ISAR三维成像算法是利用多个雷达成像之间的干涉获取目标三维信息，是ISAR成像技术和干涉测角技术的结合。本文主要对干涉ISAR三维成像算法原理进行阐述，对其成像过程中的一些问题进行分析和解决，通过仿真结果证明，该算法可以获得不错的三维成像效果，基本能满足目标识别中对目标三维信息的需求。
[Abstract]:With the development of traditional inverse synthetic Aperture Radar (ISAR) imaging technology, the restrictive conditions are proposed step by step in some complex cases. In recent years, researchers at home and abroad have done many other researches to solve the limitation of traditional ISAR imaging. Traditional R-D imaging algorithm for ISAR imaging in practical applications, due to many complex factors, resulting in the available imaging accumulation time is short, so it may not reach the required azimuth resolution, affect the imaging effect and then affect the target recognition. At the same time, the image is the projection of the target on the vertical plane of the rotating axis between the target and the radar, which is the compression of the three-dimensional space target in the two-dimensional plane. It can not meet the requirement of 3D imaging of space 3D target by target recognition. This paper mainly focuses on other algorithms which can solve the limitation problem of traditional R-D imaging algorithm to some extent and get good results. In this paper, the basic principle of traditional R-D algorithm for ISAR imaging is introduced, and the ISAR imaging model of stationary moving target, radar transmitting signal and echo processing method are introduced. The range and azimuth resolution of the R-D algorithm and the different motion compensation methods needed for the imaging are also discussed. The simulation results show that the traditional R-D algorithm is correct and effective. According to the different limitations of the traditional R-D algorithm, the following two aspects are studied in this paper. Distributed ISAR imaging algorithm is a new ISAR imaging technology proposed in recent years. It uses multiple transceiver radars to transmit a set of radio frequency signals to the same target, and selects, interpolates and combines the one-dimensional range images received by different radars. Finally, the method of azimuth Doppler resolution imaging is applied to the combined data to solve the problem of insufficient coherent accumulation time in complex cases. In this paper, we mainly study the imaging effect of distributed MIMO-ISAR imaging algorithm on stationary moving target in several different cases. The theoretical and simulation results show that the method can achieve azimuth resolution under different conditions. Reduce imaging time, or improve imaging resolution while ensuring imaging time. The method of shortening imaging time expands the application range of ISAR imaging and improves the effect of ISAR imaging. Interferometric ISAR 3D imaging algorithm is a combination of ISAR imaging technology and interferometric angle-measuring technique, which uses the interference between multiple radar imaging to obtain 3D information of the target. In this paper, the principle of the interferometric ISAR 3D imaging algorithm is described, and some problems in the imaging process are analyzed and solved. The simulation results show that the algorithm can obtain a good three-dimensional imaging effect. It can meet the need of 3D information in target recognition.
【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】：TN958

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