Study on the Influence of Shallow Sea Sediments on the Frequency Dispersion of Scholte Wave in Ship Seismic Wave

Abstract:
In order to study the influence of shallow sediment layer on the dispersion characteristics of ship Scholte wave, based on the shallow sea acoustic field model, the simulation of ship seismic wave propagation process in shallow sea environment with and without sediment layer is carried out by using the high-order alternating grid finite difference method. The results show that: Shallow-sea sedimentary layer has no effect on the wave field components of ship seismic waves. The wave field contains many kinds of waves, among which Scholte waves all have characteristics of slow attenuation and long propagation distance, and appear dispersion phenomenon., among them, Scholte waves have the characteristics of slow attenuation, long propagation distance and dispersion. The f-k transform method was used to extract the Scholte wave dispersion energy curves in the non-sedimentary layer, gravel layer, and silt layer. The analysis results show that the sedimentary layer promotes the Scholte wave dispersion and increases the wave speed range, that the frequency mainly concentrated in 5Hz-40Hz. The research results provide a theoretical basis for target detection in shallow water.