双声道波导中低频环境噪声分布特性

针对北极冰下双声道波导的噪声分布特性研究,采用垂直阵对双声道波导内的噪声场进行了观测,北极冰下噪声物理模型使用混合加性噪声模型描述,统计分布模型使用α稳定分布描述.并将噪声划分为3个频段,按噪声来源分为背景噪声、冲击噪声以及航船噪声3种场景,分析其统计特性,给出了直方图统计、核函数估计与正态分布的比较结果,α稳定分布参数估计结果,峰度与偏度的计算结果以及累积分布函数检验结果。经分析讨论,给出结论:双声道波导中的噪声统计分布可用α稳定分布来描述,但上下表面声道的分布参数具有明显差别,上表面波导背景噪声明显偏离高斯分布而下表面声道的背景噪声接近于高斯分布;上下表面声道中不同频带的噪声分布差异也很明显,其中2~30 Hz差异性最大,30~100 Hz差异性较大,而100~500 Hz差异性相对较小,并且可以认为是对称α稳定分布.此外,上下表面声道中不同频带噪声α稳定特征参数变化也存在差异,上表面波导受冲击噪声影响α值变大,拖尾变薄;而下表面波导受冲击噪声影响α值则会变小,拖尾变重。 

Analysis of low frequency environmental noise distribution in dual-duct waveguide

Focus on the noise distribution characteristics of Arctic dual-duct waveguide,the noise field in a dual-duct waveguide under Arctic ice is observed by a vertical array.The Arctic ice noise physical model is described by the mixed additive noise model,and the statistical distribution model is described by a-stable distribution.The noise is composed of three bands in frequency domain,and the noise is divided into three source scenarios:background noise,impact noise,and ship noise,and the statistical characteristics are analyzed.The comparison results of histogram statistics,kernel function estimation and normal distribution,estimation results of a-stable distribution parameters,calculation results of kurtosis and skewness,and cumulative distribution function test results are given.The statistical distribution of noise in dual-duct waveguides can be described by α-stable distribution,but the distribution parameters of the upper and lower duct are obviously different.The background noise of the upper duct deviates significantly from the Gaussian distribution,while the background noise of the lower duct is close to the Gaussian distribution.The difference of noise distribution in different frequency bands in the upper and lower duct is also obvious.