Analysis of underwater noise characteristics of ships in offshore waters

Abstract

Ship noise has always been one of the important sources of marine noise. In order to study the sound source characteristics of underwater radiated noise from ships, this paper is based on the monitoring data collected in the sea area of Zhoushan Zhairuo Island, to get the underwater noise signal of the measured ship under different driving speeds. Through the timefrequency domain feature analysis, the short-term energy spectrum and spectrogram of the noise signal are drawn, and the following conclusions are obtained: The frequency of ship underwater noise is mainly concentrated in the interval of 0~700Hz, with the increase of ship speed, the main frequency range of underwater noise also increases, and the noise energy at different frequencies also increases. The sound pressure level of the underwater noise of the ship selected in this experiment is in the range of 75dB~100dB. With the increase of ship speed, the sound pressure level of ship underwater noise also increases, and has a certain linear relationship. The slope estimate m is 2.442dB/knot.