Research On Polarization Transmission Characteristics In Sea Fog Environment

Sea fog is an atmospheric aerosol in a special environment,which usually brings hidden dangers to ship navigation,ocean exploration,human production and life.Sea fog is a phenomenon in which seawater evaporates and condenses in the lower atmosphere of the sea surface.When polarized light enters the sea fog,scattering and absorption occur,which changes the polarization state of the polarized light.In view of the above problems,this paper conducts in-depth research on polarization transmission characteristics in the sea fog environment.From two aspects of polarization transmission simulation and polarization transmission experiment,the effects of wavelength,incident light polarization,sea fog concentration,and sea salt content on the degree of polarization were tested.The main research contents of this article are as follows:(1)Aiming at the polarization transmission process in sea fog,based on Mie scattering theory,comprehensively considering the physical characteristics of sea fog,a polarization transmission model based on RT3 in a sea fog environment is established.The model in this paper introduces parameters such as particle spectrum distribution and complex refractive index,which are more in line with the actual sea fog polarization transmission characteristics.(2)Aiming at the problem of the influence of sea fog on polarization transmission characteristics,relevant simulation tests were carried out using the polarization transmission model,including the effects of wavelength,polarization state,sea fog concentration and salt content on the degree of polarization.The simulation results show that as the concentration of sea fog increases,light of different polarization states has a significant depolarization phenomenon.Under the same contrast conditions,circularly polarized light as a whole has better polarization maintaining characteristics than linearly polarized light.In the visible light range,the longer the wavelength of the incident light,the better the penetration effect;and the salt content in the sea fog has a certain effect on the degree of polarization.(3)Due to the shortcomings of strong randomness,poor controllability,and difficulty in carrying out multiple repeated experiments in external field experimental research,an indoor sea fog simulation device is designed and implemented in this article.In the experiment,Na Cl was selected as the sea fog condensation nuclei,and the polarization state and wavelength of the incident light were used as variables to study the variation of the polarization transmission characteristics of the laser under different conditions.The simulation and experimental results are compared with the optical thickness as a variable.It can be seen from the calculation results of the similarity measure that the simulation and experimental results basically agree with each other and can be mutually verified.