Research On Time Tame Method Of Underwater Optical Communication

The marine environment is complex,precise underwater positioning,and deep sea operations require accurate clock frequency support.In this paper,the underwater laser clock tame method is used to effectively overcome the shortcomings of traditional low-speed,high-delay,and serious attenuation of electromagnetic wave underwater timing,and provide a new research direction for underwater time tame.The article first introduces the research background and significance,and then based on the underwater laser transmission method and clock taming method,an underwater laser clock taming method and model is obtained,which makes up for the shortcomings of underwater acoustic timing and underwater optical fiber wired timing,and then based on An optimized(FS,Fournier-Sanjay)volume scattering function established underwater laser transmission model,analyzed the underwater receive beam characteristics,and finally studied the time domain impulse response model.The following is the main research content of this article:(1)The optical characteristics of photons in seawater are introduced.The advantages and disadvantages of various volume scattering functions are studied,and an optimized FS volume scattering function is obtained,which is based on the average particle volume scattering function obtained by recognized experiments and evaluated with the prediction results of other volume scattering functions.Other volume scattering functions are closer to the average particle volume scattering function.The underwater laser transmission channel model established by the small angle approximation method and the Monte Carlo method(MC,Monte-Carle)is analyzed,and the MC model is a Markov process formed by a series of basic scattering events.The method is more suitable for the complex and changeable characteristics of the seawater channel,so the MC method is chosen to establish the underwater laser transmission channel model.(2)Using the underwater laser transmission channel model based on the FS volume scattering function combined with the MC method,the beam spreading characteristics are studied,and the effects of the transmission distance and the receiving field angle on the beam power density are analyzed.A light source model of optical soliton pulses was established,using optical soliton pulses,Gaussian pulses and flat top pulses as the emission light sources.The receive beam characteristics of different emission light sources were discussed.(3)Several types of underwater laser time-domain impulse response models are described,and a dual-link exponential power function(DEF)model is derived through improved optimization.The MC model based on the FS volume scattering function is used to obtain the domain impulse response results are evaluated with other time domain impulse response models,proving that the DEF model can fit the time domain impulse response obtained by the MC model more accurately.The paper mainly draws an optimized FS volume scattering function.The characteristics of underwater laser in the taming of underwater laser clocks are analyzed,and the beam characteristics of optical soliton pulses as light sources are studied.Several closedtime impulse response function models are introduced,and a DEF function model is derived for theoretical analysis of underwater laser clock tame.