The ambient sound field in the ocean can be decomposed into a linear combination of two independent fields attributable to wind-generated wave action at the surface and noise radiated by ships. The vertical coherence (the cross-spectrum normalized by the power spectra) and normalized directionality of wind-generated noise in the ocean are stationary in time, do not vary with source strength and spectral characteristics, and depend primarily on the local sound speed and the geoacoustic properties which define the propagation environment. The contribution to the noise coherence due to passing vessels depends on the range between the source and receiver, the propagation environment, and the effective bandwidth of the characteristic source spectrum. Using noise coherence models for both types of the sources, an inversion scheme is developed for the relative and absolute contribution of frequency dependent ship noise to the total sound field. A month-long continuous ambient sound recording collected on a pair of vertically aligned hydrophones near Alvin Canyon at the New England shelf break is decomposed into time-dependent ship noise and wind-driven noise power spectra. The processing technique can be used to quantify the impact of human activity on the sound field above the natural dynamic background noise, or to eliminate ship noise from a passive acoustic monitoring data set.

中文翻译：

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量化船舶噪声对水下声场的影响

海洋中的环境声场可以分解为两个独立场的线性组合，这两个场归因于表面的风生波作用和船舶辐射的噪声。海洋中由风产生的噪声的垂直相干性（通过功率谱归一化的频谱）和归一化的方向性在时间上是固定的，不会随源强度和频谱特性而变化，并且主要取决于本地声速和定义传播环境的地声特性。由于通过船只而对噪声相干性的影响取决于源和接收器之间的范围，传播环境以及特征源频谱的有效带宽。对两种类型的信号源使用噪声相干模型，针对频率相关的船舶噪声对总声场的相对和绝对影响，开发了一种反演方案。在新英格兰架子断裂处的阿尔文峡谷附近的一对垂直对准的水听器上收集的为期一个月的连续环境声音记录被分解为与时间有关的船舶噪声和风噪声功率谱。该处理技术可用于量化人类活动对自然动态背景噪声之上的声场的影响，或用于从无源声学监控数据集中消除船舶噪声。在新英格兰架子断裂处的阿尔文峡谷附近的一对垂直对准的水听器上收集的为期一个月的连续环境声音记录被分解为与时间有关的船舶噪声和风噪声功率谱。该处理技术可用于量化人类活动对自然动态背景噪声之上的声场的影响，或用于从无源声学监控数据集中消除船舶噪声。在新英格兰架子断裂处的阿尔文峡谷附近的一对垂直对准的水听器上收集的为期一个月的连续环境声音记录被分解为与时间有关的船舶噪声和风噪声功率谱。该处理技术可用于量化人类活动对自然动态背景噪声之上的声场的影响，或用于从无源声学监控数据集中消除船舶噪声。