Modeling of ambient and ship noise in underwater ocean environment of the Bay of Bengal

Abstract

In this paper, we model the ambient noise with and without ship noise data collected from the shallow waters of the Bay of Bengal. The wind speed and temperature were approximately constant for both the noise data. The ambient noise was collected using hydrophones at a depth of 5m and 15m from the surface, while the ambient noise added with ship noise data was collected using hydrophones at a depth of 3m and 5m. Statistical analysis of the ambient noise reveals that it follows Weibull distribution. Ambient noise along with ship noise is observed to exhibit Generalized Gaussian probability density function pdf. It is observed that both the noises collected near the surface exhibit higher variance compared to that collected at a deeper level in the ocean. The power spectral density analysis of the ambient noise with and without ship noise, at 5m hydrophone depth, shows the dominant frequency band to be up to 3KHz. Further, it is observed that though the power spectral density of both noises dominates over almost the same frequency range, these can be differentiated based on variations in their statistics.