Improving Scholte-Wave Vibration Signal Recognition Based on Polarization Characteristics in Coastal Waters

摘要

Scholte waves on the underwater interface provide a lot of information, which can be employed to identify the target in coastal water and speculate the coastal underwater medium. However, as the practical acquired signals are the superposition of multiple wave fields, it is necessary to separate the Scholte wave and to improve its signal-to-noise ratio. The LS-DYNA software was used to simulate the underwater acoustic field to analyze the excitation mechanism and particle trajectory law of Scholte waves and to obtain the propagation characteristic of Scholte waves. The results showed that Scholte waves attenuate according to r(-0.5) on the underwater interface and according to exponent in the depth direction. The amplitude of Scholte waves mainly concentrates below 25 Hz, and the corresponding particle trajectory makes a counterclockwise elliptical shape by filtering the acquired signals of particle vibration velocity below 25 Hz on and below the underwater interface. This method was applied to separate Scholte waves from the acquired complex signals of the wave field in the lake experiment to obtain the pure signals of the Scholte wave. This research can provide significant knowledge to better take advantage of resourceful information provided by Scholte waves in the coastal environment.