Analysis Of The Impact Of The Dynamic Changes Of The Marine Environment On The Underwater Acoustic Channel

With the advent of the information age,human research on communications has gradually developed from land and air to the vast ocean field.Due to the continuous expansion of the development of marine resources and the increasing number of military operations on the water,the need to use marine media as acoustic signal transmission channels has greatly increased.H owever,there are practical problems such as high costs and long periods in field sea trials.Therefore,the establishment of a time-varying multipath underwater acoustic channel model suitable for specific sea environment has certain guiding significance for actual marine surveys.This paper mainly establishes a time-varying multipath underwater acoustic channel model suitable for the South China Sea,and analyzes the influence of environmental changes in the South China Sea on the characteristics of the underwater acoustic channel.The research contents are as follows:Pre-processing the annual temperature and salinity reanalysis products and global topographic elevation data of the South China Sea,mainly including the speed of sound in the sea and the topography of the seabed,as a dynamic parameter in the marine three-dimensional environment,to restore the actual state of the marine environment in the South China Sea to a certain extent.The large-scale channel model with slow time-varying and stable characteristics and the small-scale channel model with fast time-varying and random characteristics are established respectively.Based on the dynamic parameters of the marine three-dimensional environment of the South China Sea,an underwater acoustic channel model based on large-scale effects is established.The experimental simulation results show that,for the South China Sea environment,the BELLHOP3 D model using the Gaussian beam tracking method has better simulation performance than the geometric path model;The simulation results of the BELLHOP3 D model is used as the channel model of the background field of the large-scale effects,and the small-scale effect is superimposed on each cluster of sound ray paths to make the micro-path disturbed.A simulation method of the underwater channel lightweight model with superimposed small-scale effects is proposed.From the perspective of channel impulse response,channel transmission matrix and instantaneous channel gain,the experimental simulation results show that the statistical equivalent model has more advantages in reflecting the time-varying nature of the underwater acoustic channel in the South China Sea.Using the time-varying multipath underwater acoustic channel model established in this paper,which is suitable for the South China Sea,combined with the changes of the four seasons and the position of the sea area,the influence of the changes of the environmental dynamic parameters in the South China Sea area on the characteristics of the underwater acoustic channel is statistically analyzed.