Underwater acoustic channel modeling under different shallow seabed topography and sediment environment

Abstract

Due to the topographic fluctuation and changeable composition of the seabed, it has a vital impact on the sound propagation trajectory and attenuation in the ocean. Based on the bellhop Gaussian beam ray tracing model, this paper focuses on the sound propagation characteristics in the environments of two typical seabed topography like seamount and slope, and two sediment like silty clay and coarse sand. The propagation loss and time delay are obtained by inputting different marine environmental parameters through bellhop model. Then these parameters are input into the impact response of underwater acoustic multipath channel to obtain underwater acoustic channel models under different shallow seabed topography and sediment environment. The results show that the propagation loss of coarse sand is increased by 6dB compared with silty clay sediment. After passing through the seamount, the sound propagation loss increases by 5-10 dB compared with the flat terrain without seamount. Due to the influence of slope reflection, the average propagation loss of uphill seabed is 0.6dB smaller than that of downhill seabed. At the same time, when the parameters of different marine environments are input into bellhop model, the channel impulse response obtained by the receiver includes the energy and time series of each eigenray, and the underwater acoustic channels in different marine environments can be obtained.