海杂波幅度分布参数矩估计和恒虚警检测

发布时间：2018-09-08 15:37

【摘要】：近年来,随着海杂波研究工作的重要性在军事和民用领域日益突出,海杂波背景下的动目标检测问题已经是雷达技术领域的热点问题。而海杂波统计特性的准确分析是有效检测目标的先决条件。现如今,由于模型的有效性,K分布杂波模型越来越多地被用于海杂波的分析、建模和仿真。K分布杂波背景下的运动目标检测问题已经被广泛研究和应用。因此,K分布杂波的参数估计问题和K分布杂波背景下的恒虚警检测方案便成了实际应用中的重要研究课题。在本文中,首先回顾了海杂波的统计特性。这其中包括杂波的幅度分布特性和杂波序列的相关性。在杂波幅度分布特性方面,重点介绍了几种常用的杂波分布模型,并对它们的性质和适用范围作了分析;在杂波序列的相关性方面,重点分析了杂波沿时间方向和空间方向的相关性。其次,介绍几种经典的适用于海杂波背景下的目标检测器,包括单元平均恒虚警检测器、广义似然比检测器、自适应匹配滤波检测器和自适应归一化匹配滤波检测器。针对单元平均恒虚警检测器存在的缺陷,本文提出了比率中值检测方法,该方法使用二维参考滑窗,具有抗异常散射单元的能力。同时,在实测海杂波数据条件下,本文对单元平均恒虚警检测器和比率中值检测器的检测性能做了对比。与单元平均恒虚警检测器相比,本文提出的方法在含有异常单元的杂波环境中具有更好的检测性能。最后,海杂波K分布参数的矩估计方法被研究,这构成了在K分布杂波下匹配滤波检测器和归一化匹配滤波检测器恒虚警门限设置的基础。证明了匹配滤波检测器和归一化匹配滤波检测器的恒虚警门限仅由累积的脉冲数和K分布杂波的形状参数确定。紧接着,推导出了匹配滤波检测器和归一化匹配滤波检测器恒虚警门限的表达式并且提出了恒虚警门限的Monte-Carlo积分计算方法。最后,我们仿真了具有空变形状参数的K分布杂波数据并用它检验了匹配滤波检测器和归一化匹配滤波检测器的恒虚警性质。而且,用实测的海杂波数据来检验自适应匹配滤波检测器的恒虚警性质。
[Abstract]:In recent years, with the increasing importance of sea clutter research in military and civil fields, the detection of moving targets in sea clutter background has become a hot issue in radar technology. The accurate analysis of sea clutter statistical characteristics is a prerequisite for effective detection of targets. M is more and more used in the analysis, modeling and Simulation of sea clutter. The problem of moving target detection in K-distributed clutter background has been widely studied and applied. Therefore, the parameter estimation of K-distributed clutter and CFAR detection scheme in K-distributed clutter background have become important research topics in practical applications. This paper reviews the statistical characteristics of sea clutter, including the amplitude distribution of clutter and the correlation between clutter sequences. In the aspect of clutter amplitude distribution characteristics, several commonly used clutter distribution models are introduced, and their properties and application range are analyzed. Secondly, several classical target detectors for sea clutter background are introduced, including cell average CFAR detector, generalized likelihood ratio detector, adaptive matched filter detector and adaptive normalized matched filter detector. In this paper, a ratio median detection method is proposed, which uses a two-dimensional reference sliding window and has the ability to resist anomalous scattering units. At the same time, the detection performance of the unit-average CFAR detector and the ratio median detector is compared with that of the unit-average CFAR detector under the condition of actual sea clutter data. Finally, the moment estimation method for K-distribution parameters of sea clutter is studied, which forms the basis for setting CFAR threshold of matched filter detector and normalized matched filter detector under K-distribution clutter. The CFAR threshold of the wave detector is determined only by the cumulative number of pulses and the shape parameters of the K-distribution clutter. Then, the expressions of CFAR threshold for the matched filter detector and the normalized matched filter detector are derived, and the Monte-Carlo integral method for CFAR threshold is proposed. Finally, we simulate the shape of the null deformation. The constant false alarm property of the matched filter detector and the normalized matched filter detector is tested by using the K-distribution clutter data of the parameter.
【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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