舰船噪声小波谱提取方法研究

人耳听测舰船噪声的特征,是声纳员非常重要的专业技能。本文根据小波变换与人耳蜗频率响应相近似的特点,以cmor1-0.5母小波为基础,构造了一系列基于小波变换的滤波器组。对于小波谱提取中涉及的带宽、分辨率等参数进行了分析,提出了小波谱提取过程中改善分辨率的办法。为检验该方法的可行性,对三种不同类型的舰船噪声进行了小波谱分析,与其FFT谱图进行了比较。为解决小波谱提取过程中高分辨率与计算量的矛盾,提出了对指定频带进行小波谱分析的方法,解决了计算量的问题。

Wavelet spectrum for ship-radiated noise extraction

Extracting features of ship-radiated noise by listening and monitoring is an important factor in sonar operation.Since wavelet transform is similar to the frequency response of human beings’ cochlea,in this paper,the construction of the wavelet-based filter bank was is chosen on the cmor1-0.5 wavelet base,and the wavelet spectrum is determined.The corresponding bandwidth and spectrum resolution are analysed and several methods brought forword to improve the spectrum resolution.In order to check the feasibility of the methods,the wavelet spectra of 3 different kinds of ship-radiated noise are obtained and analysed by discrete wavelet transform.Furthermore,the wavelet spectrum of the ship-radiated noise is compared with its FFT spectrum and thus that within a specified bandwidth is obtained.