The depth dependence and vertical directivity of shipping noise in deep ocean trenches

Studying on ocean ambient noise is important for understanding noise generation and propagation for designing sonar processing systems. Based on the reciprocity of the sound field, a model of distant shipping noise in range dependent environments is described in this paper. The complex pressures are calculated using a parabolic equation (PE) model. The properties of the shipping noise over a deep ocean trench are analyzed. Deep ocean trenches provide significantly reduced shipping noise by blocking horizontally arriving noise and will not block the sound propagation from a target with middle ranges, which result in improved SNR for better detection.