| The polar region has rich resources,high scientific research value and significant strategic position.The accelerated melting of glaciers caused by global warming provides conditions for the opening of new channels in the polar region.The study of underwater acoustic propagation characteristics in polar regions is one of the bases of scientific investigation in polar waters.Therefore,more and more attention has been paid to the study of underwater acoustic propagation and its characteristics in polar regions.Due to the positive gradient of sound velocity gradient and the existence of ice water interface,the underwater propagation of sound line becomes more complex in this special sound field environment,which makes it difficult to model and predict the sound field.Based on the ray theory and B-T model,the sound propagation under ice is simulated,and the characteristics of sound field and sound propagation are analyzed.Firstly,the ray acoustic theory and the approximation conditions of acoustic ray are introduced,which lays the foundation for the subsequent sound field modeling.Then the sound velocity profile is configured,and combined with B-T ice water interface scattering model and sound propagation seabed model,the whole sound field environment is built.According to different working conditions,the sound propagation characteristics are simulated and analyzed.The research contents mainly include: the sound propagation trajectory and propagation loss under different sound source frequency,sea depth,seabed topography and with or without ice floe are simulated,and the variation law of horizontal propagation loss under different depths is studied.Finally,the submarine reverberation signal in the polar sub ice area is predicted,and its autocorrelation characteristics are calculated.The spectrum characteristics,instantaneous statistical characteristics and envelope distribution of reverberation are analyzed.In this paper,the underwater acoustic toolbox based on MATLAB is redeveloped,and the underwater acoustic propagation characteristics in polar regions are studied,which has a certain reference value for polar underwater acoustic detection and underwater communication. |
