时频分布重排方法在水下目标回声识别中的应用  

Application of time-frequency distribution reassignment method to underwater target echo classification

作　　者：林正青[1] 牟林[1] 彭圆[1] 张风珍[1] 

机构地区：[1]水下测控技术国防科技重点实验室,大连116013

出　　处：《应用声学》2014年第1期87-94,共8页Journal of Applied Acoustics

基　　金：国家重点实验室基金项目(51303020307-8;4010201030301)

摘　　要：特征提取是目标识别的关键技术,本文提出了一种基于时频分布重排的Wigner-Ville分布(WD)特征提取方法。选择WD作为研究问题的切入点,使用核函数方法,通过平滑伪Wigner-Ville分布(SPWD)抑制交叉项;为解决引入核函数导致信号时频聚集性下降问题,我们采用时频重排方法来增强目标的时频聚集性,最后用海上实验数据对本文方法进行了有效性检验。实验结果表明,本文提出的SPWD时频重排特征提取方法具有:(1)可有效抑制WD固有的交叉项;(2)增强目标回声信号时频聚集性;(3)可明显地提高水下目标识别率。该方法具有一定的应用推广价值,为解决水下目标识别问题提供了很好的思路。Feature extraction is a key technology for target classification. In this paper a Wigner-Ville distribution feature extraction method based on time-frequency reassignment theory was proposed. The kernel function method and the smoothed pseudo Wigner-Ville distribution（SPWD） were used to restrain the cross items. To solve the problem of which the kernel function method may cause signal time-frequency aggregation decrea- sing, a time-frequency distribution reassignment method was applied to enhance the target time-frequency ag- gregation. Finally, the effectiveness of the method was testified by sea experiment data. The experimental results show that the advantages of SPWD time-frequency distribution reassignment feature extraction method are as follows ： （ 1 ） restraining the cross items effectively ; （2） enhancing target echo time-frequency aggregation ; and （3） increasing target classification rate. This paper provides a good method for underwater target classification which has promising application prospects.

关 键 词：时频分布 重排 WIGNER-VILLE分布 

分 类 号：TN972.2[电子电信—信号与信息处理] TP391.4[电子电信—信息与通信工程]