A Method of Sound Propagation Loss Calculation based on Gaussian Beams

Abstract

In this paper, the method of underwater sound field calculation based on Gaussian beam theory is studied. We get sound line trajectory through ray acoustic theory. Then the Gaussian beam method is used to calculate the sound propagation loss. Ray acoustic method is a commonly used modeling method of sound field which is suitable for the calculation of sound field in high frequency condition. The traditional ray methods have the advantages of simple mathematical operation and intuitive physical meaning. The Gaussian beam theory introduced from the field of earthquake deals with problems of the caustic line. It connects each sound line in the sound beam with the Gaussian intensity profile perpendicular to the sound line. The two differential equations that constrain the beam width and curvature are integrated with the standard ray equation to calculate the sound field near the center line of the beam. Then it avoids the influence of transcendental knowledge on the sound line trajectory, which results in the infinite energy on the ideal sound area and the caustic line. In addition, this technology is very attractive for high frequency applications related to distance, considering it is not practical to apply wave theory in such occasions. Through modeling, simulation and computing using Matlab tools, we see that better calculation of sound field can be made by the combination of Gaussian beam method and ray acoustic theory.