基于小波分析的侧扫声呐信号非线性增强算法  

Nonlinear Enhancement Algorithm of Side Scan Sonar Signal Based on Wavelet Analysis

作　　者：王磊[1,2] 金绍华 崔杨 边刚 魏源 WANG Lei;JIN Shaohua;CUI Yang;BIAN Gang;WEI Yuan(Department of Military Oceanography and Hydrography&Cartography,Dalian Naval Academy,Dalian 116018,China;No.92763 Unit of PLA,Dalian 116041,China;No.91937 Unit of PLA,Zhoushan 316002,China)

机构地区：[1]海军大连舰艇学院军事海洋与测绘系,辽宁大连116018 [2]中国人民解放军92763部队,辽宁大连116041 [3]中国人民解放军91937部队,浙江舟山316002

出　　处：《数字海洋与水下攻防》2021年第4期288-293,共6页Digital Ocean & Underwater Warfare

基　　金：国家自然科学基金(41876103)。

摘　　要：侧扫声呐回波信号是形成侧扫声呐图像的基础,是侧扫声呐系统对水下目标的最直接观测量,将一维小波变换与非线性增强方法相结合,提出了一种基于小波变换的侧扫声呐回波信号非线性增强算法,用以改善侧扫声呐图像对比度低、噪声强度大的问题。首先利用改进的Bayes阈值对侧扫声呐ping信号进行一维小波分解,提取信号特征信息;然后利用2种不同的非线性函数对高、低频小波系数进行处理;最后利用小波反变换重构信号,形成增强后的侧扫声呐图像。实测数据验证结果表明:利用该算法对侧扫声呐ping信号进行处理,实现了侧扫声呐图像对比度的增强和对噪声的抑制,可以获取较好的图像视觉效果。The sidescan sonar echo signal is the foundation for sidescan sonar image formation,and it is the most directly observed quantity of the underwater target by the side scan sonar.Combining one-dimensional wavelet transform with nonlinear enhancement method,this paper proposes a nonlinear enhancement algorithm of side scan sonar signal based on wavelet analysis to improve the problems of low contrast and strong noise intensity of the side scan sonar image.Firstly,the one-dimensional wavelet decomposition is performed on the ping signal of side scan sonar with improved BayesShrink to obtain signal characteristic information.Then two different nonlinear functions are used to process the high frequency and low frequency coefficients.Finally,the inverse wavelet transform is used to reconstruct the signal to form an enhanced image.The verification result of measured data shows that the method proposed by this paper can realize the enhancement of image contrast and the noise suppression,and can obtain a better visual effect of image.

关 键 词：侧扫声呐 信号增强 小波变换 非线性增强函数 

分 类 号：P229.3[天文地球—大地测量学与测量工程]