航空学报 > 2016, Vol. 37 Issue (7): 2259-2268   doi: 10.7527/S1000-6893.2015.0348

一种变信噪比条件下的恒虚警野值检测方法

汝小虎, 柳征, 姜文利, 黄知涛   

  1. 国防科学技术大学 电子科学与工程学院, 长沙 410073
  • 收稿日期:2015-07-20 修回日期:2015-12-19 出版日期:2016-07-15 发布日期:2015-12-28
  • 通讯作者: 汝小虎 男,博士研究生。主要研究方向:雷达辐射源识别。Tel:0731-84573490,E-mail:ruxiaohu88@163.com E-mail:ruxiaohu88@163.com
  • 作者简介:柳征 男,博士,副研究员,硕士生导师。主要研究方向:雷达信号处理,航天电子侦察信号处理。Tel:0731-84573490,E-mail:nudtlz@163.com;姜文利 男,博士,教授,博士生导师。主要研究方向:雷达信号处理,航天电子侦察信号处理。Tel:0731-84573490,E-mail:jiangwl@nudt.edu.cn;黄知涛 男,博士,教授,博士生导师。主要研究方向:通信信号处理,卫星通信侦察与对抗。Tel:0731-84574470,E-mail:taldcn;@sina.cn
  • 基金资助:

    国家自然科学基金(61002026)

A CFAR outlier detection method under varying SNR conditions

RU Xiaohu, LIU Zheng, JIANG Wenli, HUANG Zhitao   

  1. College of Electronic Science and Engineering, National University of Defense Technology, Changsha 410073, China
  • Received:2015-07-20 Revised:2015-12-19 Online:2016-07-15 Published:2015-12-28
  • Supported by:

    National Natural Science Foundation of China (61002026)

摘要:

野值检测又称异常值检测,是模式识别、机器智能和知识发现等领域经常面临的一个问题。当出现环境失配,数据信噪比(SNR)发生变化时,测试样本和训练样本所含噪声会有不同方差,以往的野值检测方法在虚警控制方面将会失效。针对这一问题,提出一种基于归一化残差(NR)的野值检测方法。该方法首先根据所需虚警概率和噪声方差变化情况确定野值检测门限,其次基于训练样本计算待考查模式的NR值,再比较NR值与检测门限的相对大小,从而判断待考查模式是否为野值。这一方法所依赖的检测门限对所需虚警率和噪声方差变化具有适应能力,因此可以在变信噪比条件下实现恒虚警(CFAR)野值检测。仿真实验验证了所提方法在虚警控制和野值检测方面的优越性能。

关键词: 模式识别, 野值检测, 恒虚警, 虚警概率, 归一化残差

Abstract:

Outlier detection, also called anomaly detection, is a commonly encountered problem in areas such as pattern recognition, machine intelligence and knowledge discovery. When environmental mismatch occurs and the signal-to-noise ratio (SNR) of data changes, the noise variances in testing and training instances will be different, resulting in the ineffectiveness of previous outlier detection methods which aim to control the false-alarm probability. To solve the problem, an outlier detection method based on normalized residual (NR) is proposed in this paper. This method first calculates the outlier detection threshold according to the desired false-alarm probability and the change of noise variance; second measures the NR value of the query pattern using training instances; and then compares this NR value with the predefined detection threshold to determine whether the query pattern is an outlier or not. The detection threshold defined in this paper is adaptive to the desired false-alarm probability and the varying noise variance, thus can realize constant false-alarm rate (CFAR) outlier detection under varying SNR conditions. Simulation experiments validate the superior performance of the proposed method on false-alarm probability controlling and outlier detection.

Key words: pattern recognition, outlier detection, constant false-alarm rate (CFAR), false-alarm probability, normalized residual

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