Numerical Simulation Of Laser Propagation In Random Rough Sea Surface And Seawater Environment

Compared with the traditional submarine communication technology relying on microwave or shortwave,laser submarine communication has the advantages of good concealment and high data transmission rate,and has a good development prospect.From transmitting to receiving,Lasers need to pass through atmospheric channels,air-sea interfaces and seawater channels.The transmission of lasers in the air-sea interface and in the seawater is much more complicated than the transmission in the atmosphere,and the random complexity of the marine environment also severely limits the development of laser underwater communication technology,Therefore,it is of great significance to study the transmission of lasers in random rough seas and seawater.In this paper,using FORTRAN's self-compiled program,based on the Monte-Carlo Method,the laser transmission characteristics in random rough seas and complex seawater environments are studied.The main research process includes the following parts:First,three common sea surface power spectrum models and sea surface simulation methods are analyzed and compared.P-M spectrum model is selected,and the MonteCarlo Method based on fast Fourier transform is used to simulate random rough sea surface and the correctness of the sea surface model is verified.The features of sea surface random fluctuation height under diverse sea surface wind speeds are studied.Secondly,the sea surface grid is divided and the grid independence is verified.Based on the Monte-Carlo Method,the laser Gaussian beam emission source is simulated,and an algorithm for quickly finding the intersection point between the light and the sea surface grid is proposed and verified.The sea surface laser transmission model(reflection model and transmission model)and the hemispheric light intensity receiving surface model are established.The algorithm flow of sea surface laser transmission simulation is proposed and verified.Under different sea surface wind speeds,the laser transmission characteristics of random rough sea surface are studied.Finally,a seawater laser transmission model is constructed,including probability model and attenuation model,and the seawater laser transmission simulation algorithm flow is established.The attenuation process of a great quantity of photons in seawater is simulated based on Monte-Carlo Method.The effects of various seawater optical parameters,different seawater types,and different sea surface wind speeds on seawater laser transmission are studied.