海杂波背景下机载雷达目标检测与性能评估

发布时间：2018-08-10 21:08

【摘要】：我国海洋国土面积广阔,环境复杂,利用机载雷达对我国海洋国土进行侦察和监视是一种非常重要的途径。当机载雷达工作在海洋环境中时,接收回来大多数后向散射回波是人们不想要的回波,研究海杂波特性和海杂波背景下的目标检测方法对我国经济和国防建设具有非常重要的意义。针对落在主瓣边缘目标存在信噪比损失问题,提出了一种自适应双指向和差波束的目标联合检测方法,它能有效补偿接收波束边缘增益损失,同时能够实现目标角度估计。在海杂波特性研究方面,针对信号处理后杂波特性的理论分析比较困难的问题,给出了基于球不变随机过程(spherically invariant random processes,SIRP)法仿真的信号处理前后的杂波特性分析,得到了信号处理前后杂波特性的变化关系。本文的主要工作如下:1.分析了机载雷达海杂波信号模型和基本的空时自适应信号处理技术,接着分别分析了常规自适应和波束的目标检测方法、传统自适应和差波束的目标联合检测方法,并提出了一种自适应双指向和差波束的目标联合检测新方法,最后通过仿真实验对比分析了这三种目标检测方法的检测性能。2.分析了海杂波统计分布的几种常用模型,并且分析了估计模型参数的几种常用方法,接着基于K分布模型研究了它的两种等效模型Gamma分布与高斯分布,并且对比了两种等效模型的准确性。最后根据K分布可以在一定范围用Gamma分布等效的特点,分析了一种K分布的快速估计方法。3.分析了一种基于SIRP的K分布空时二维海杂波数据仿真模型,接着在此模型基础上仿真分析了信号处理前后K分布海杂波的特性变化。最后分析了2/4准则下检测盲区图的计算方法,并通过仿真实验得到Rayleigh分布海杂波数据经FA(factored approach)处理后在2/4检测准则下的检测盲区图。
[Abstract]:The marine land area of our country is vast and the environment is complex. It is a very important way to use airborne radar to carry on reconnaissance and surveillance to our country's marine land. When the airborne radar works in the marine environment, receiving most of the backscattering echoes is unwanted. It is very important to study the characteristics of sea clutter and the method of target detection in the background of sea clutter for the economic and national defense construction of our country. Aiming at the problem of SNR loss of the target falling on the main lobe edge, an adaptive joint detection method of double pointing and differential beam is proposed, which can effectively compensate the edge gain loss of the receiving beam and realize the target angle estimation. In the research of sea clutter characteristics, aiming at the difficult problem of theoretical analysis of clutter characteristics after signal processing, this paper presents the analysis of clutter characteristics before and after signal processing based on the spherical invariant stochastic process (spherically invariant random processes SIRP method. The relationship of clutter characteristics before and after signal processing is obtained. The main work of this paper is as follows: 1. The model of airborne radar sea clutter signal and the basic space-time adaptive signal processing technology are analyzed. Then the conventional adaptive and beam detection methods and the conventional adaptive and differential beam combined detection methods are analyzed respectively. A new method of target joint detection based on adaptive double pointing and differential beam is proposed. Finally, the detection performance of these three methods is compared and analyzed by simulation experiments. Several commonly used models for statistical distribution of sea clutter are analyzed, and several common methods for estimating model parameters are analyzed. Then, two equivalent models, Gamma distribution and Gao Si distribution, are studied based on K distribution model. The accuracy of the two equivalent models is compared. Finally, according to the characteristic that K distribution can be equivalent to Gamma distribution in a certain range, a fast estimation method of K distribution. In this paper, a simulation model of K-distributed space-time two-dimensional sea clutter data based on SIRP is analyzed. Based on this model, the characteristics of K-distributed sea clutter before and after signal processing are simulated and analyzed. Finally, the calculation method of blind area map under 2 / 4 criterion is analyzed, and the blind area map of Rayleigh distributed sea clutter data processed by FA (factored approach) after 2 / 4 detection criterion is obtained by simulation experiment.
【学位授予单位】：西安电子科技大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TN957.51

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