Modeling of High Frequency Sound Propagation Characteristics in Shallow Sea

Abstract

10kHz~38kHz High frequency sound signal is common signal form of marine acoustic equipment, when the high frequency acoustic signal propagates in seawater, it not only produces reflection and refraction on the seawater interface, but also is obviously affected by the sound absorption of seawater. In order to obtain the law of high frequency sound propagation in shallow sea, this paper uses several self-condenser hydrophones and depth sensors placed vertically at equal intervals as receiving device, fixed point high frequency sound propagation experiments with different frequency and frequency bands were carried out in a shallow sea in China. Then setting the acoustic parameters of the ocean guide and the acoustic absorption coefficient of the sea water at various frequencies, A high frequency near-field acoustic propagation model in shallow water is established by using ray acoustics. Finally, the measured sound propagation loss in the vertical direction of seawater is compared with the propagation loss predicted by the model. The analysis results show that different frequencies and frequency bands, at different horizontal distances, the measured propagation loss values are in good agreement with the theoretical values, and the sound propagation model established in this paper can accurately describe the high frequency sound propagation characteristics of the sea area. The research method in this paper is of great significance for the offshore calibration and performance prediction of high frequency marine acoustic equipment under shallow sea conditions.