海杂波特性及其抑制技术的研究

发布时间：2018-03-15 02:25

本文选题：海杂波特性　切入点：杂波抑制　出处：《电子科技大学》2014年硕士论文　论文类型：学位论文

【摘要】：海杂波是影响海面目标探测雷达性能的重要因素,因而海杂波抑制技术是雷达工作者的重要研究课题。而对海杂波特性的研究有助于加深对海杂波的认识,从而有助于雷达系统方案的设计和海杂波抑制算法的研究。论文针对海杂波特性及其抑制技术进行了如下的研究工作:首先,分析了海杂波后向散射系数与雷达工作频率、极化方式、海况、风向与雷达视角之间的夹角等物理量的关系;讨论了海杂波的空时相关特性、海杂波的四种统计分布模型(Weibull分布、Lognormal分布、复合K分布、广义复合分布)及其建模方法、海杂波幅度与功率谱的非平稳特征,并模拟了四种统计分布模型的海杂波。其次,详细阐述了海洋动力学参数的反演过程,分析了海况等级、风速、浪高之间的经验关系,提出了基于海洋动力学参数估计海杂波多普勒频率和谱宽,继而进行海杂波抑制方法的研究,并用IPIX雷达的实测海杂波数据进行了仿真实验,取得了一定的效果。再次,分别研究了基于AR模型和基于SVM的海杂波抑制技术。在基于AR模型的海杂波抑制技术中,详细介绍了AR模型的基本理论,阐述了AR白化滤波器抑制海杂波的原理,用实测数据进行实验并分析实验结果;在基于SVM的海杂波抑制技术中,详细阐述了SVM原理与SVM时间序列预测方法,分析了各参数对SVM性能的影响,并用实测数据进行仿真实验,比较其与AR模型的性能。最后,实现了基于PowerPC硬件平台的海杂波模拟软件设计。介绍了PowerPC的结构特点及其在处理复杂信号方面的优势,说明了嵌入式软件开发环境Tornado的特点、在该环境下实现海杂波的模拟的方法,并用原型仿真器VxSim进行仿真,给出了海杂波模拟的实验结果。论文中对海杂波特性的分析是海杂波抑制技术的研究基础,在三种海杂波抑制技术中,基于AR模型的海杂波抑制技术与基于SVM的海杂波抑制技术有良好的性能,而前者由于计算量小的特点,更易于工程实现,基于海洋动力学的海杂波抑制技术为海杂波抑制技术提供了新的思路。基于PowerPC硬件平台的海杂波模拟器实现为与海杂波相关的研究提供了数据来源。
[Abstract]:Sea clutter is an important factor affecting the performance of sea surface target detection radar, so sea clutter suppression technology is an important research topic for radar workers, and the study of sea clutter characteristics is helpful to deepen the understanding of sea clutter. This is helpful to the design of radar system scheme and the research of sea clutter suppression algorithm. In this paper, the characteristics of sea clutter and its suppression techniques are studied as follows: firstly, the backscattering coefficient of sea clutter and the frequency of radar are analyzed. The relation of physical quantities such as polarization mode, sea condition, wind direction and radar angle of view, the space-time correlation characteristics of sea clutter, the Weibull distribution and the compound K distribution of sea clutter are discussed. Generalized composite distribution) and its modeling method, the non-stationary characteristics of sea clutter amplitude and power spectrum, and the simulation of sea clutter of four statistical distribution models. Secondly, the inversion process of marine dynamic parameters is described in detail, and the sea condition grade is analyzed. Based on the empirical relationship between wind speed and wave height, the Doppler frequency and spectral width of sea clutter are estimated based on marine dynamic parameters, and then the suppression method of sea clutter is studied. The simulation experiments are carried out with the measured sea clutter data of IPIX radar. Thirdly, the technology of sea clutter suppression based on AR model and SVM is studied respectively. In the technology of sea clutter suppression based on AR model, the basic theory of AR model is introduced in detail. The principle of AR whitening filter for suppressing sea clutter is expounded, and the experimental results are analyzed with the measured data. In the technology of sea clutter suppression based on SVM, the principle of SVM and the prediction method of SVM time series are described in detail. The effect of various parameters on the performance of SVM is analyzed, and the performance of AR model is compared with that of real data. This paper realizes the design of sea clutter simulation software based on PowerPC hardware platform, introduces the structure characteristics of PowerPC and its advantages in dealing with complex signals, and explains the characteristics of embedded software development environment Tornado. The simulation method of sea clutter is realized in this environment, and the experimental results of sea clutter simulation are given by using the prototype simulator VxSim. The analysis of the characteristics of sea clutter in this paper is the research foundation of sea clutter suppression technology. Among the three kinds of sea clutter suppression techniques, AR model-based sea clutter suppression and SVM based sea clutter suppression have good performance. Sea clutter suppression based on marine dynamics provides a new idea for sea clutter suppression. The implementation of sea clutter simulator based on PowerPC hardware platform provides a data source for the research of sea clutter.
【学位授予单位】：电子科技大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：P715;TN957

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