Polarized Light Transmission Characteristics In Low Visibility Haze Particles

The polarization characteristic of polarized light is often used as a carrier to transmit information and can identify detection targets in complex atmospheric channel environment.In haze weather,because a large number of haze aerosols are suspended in the atmosphere,the scattering of these aerosol to polarized light greatly affects the efficiency of information transmission.In view of the polarized light transmission efficiency in haze weather conditions is poor this basic problem,in this paper,the large mass haze of aerosols and the scattering characteristics of condensed clusters modeling analysis,from the light scattering and transmission characteristics of aerosols,calculation and analysis of the composition of aerosol,transmission distance and the influence of visibility on the polarized light transmission.This paper first introduces the causes of various aerosol particles in haze,presents the morphologies of a variety of typical aerosol particles,analyzes their particle sizes and the number of particles contained in common clusters,and focuses on the dust aerosol particles and inorganic salt aerosol particles with the highest content in the atmosphere.Two kinds of methods for studying the light scattering of aerosol particles are introduced theoretically: Generalized multi-sphere mie theory(GMM)and Discrete Dipole Approximation(DDA)method.The accuracy of DDA and GMM methods is verified by taking the relatively basic single-particle aerosol and water-covered aerosol particles in the study of light scattering characteristics as the research object.In clusters of fog aerosol particles modeling,this paper introduces two kinds of commonly used clusters condensation model,Diffusion Limited condensed coursing together Limited Aggregation)DLA model and dynamic group(Cluster-Cluster Aggregation)CCA model,because of particles in the CCA model combined into small clusters,small clusters coupled with each other into closer to the nature in the formation of large clusters aerosol in the formation of clusters,so using CCA model clusters aerosol model was set up,An equivalent dielectric method for calculating the scattering characteristics of aerosol clusters is introduced.Combining with the established CCA model of aerosol cluster,this paper used GMM method to further study the light scattering characteristics of single-cluster particles and multi-cluster particles with the same and different particle sizes.It was found that the scattering characteristics of aerosol cluster particles were closely related to the imaginary part of the complex refractive index of aerosol particles.Finally in the polarized light transmission characteristics in the complex haze environment,equivalent to a single spherical clusters will aerosol particles aerosol particles,after combining the scalar and vector Monte Carlo(Monte Carlo)method,the establishment of a fog aerosol transmission model,studies the transmission distance(thickness),visibility,and other factors in natural light and polarized light role in the transmission process.Results show that in low visibility conditions,the incident light wavelength is larger,such as 10.6 mu m visibility,the greater the smoke and sulphate aerosols clusters two transmission medium to completely right-handed circularly polarized light in polarization-maintaining ability stronger,for parallel polarization of the incident ray,the bigger the visibility,smoke and dust aerosol clusters transmission medium for its polarization-maintaining ability stronger,sulphate aerosols clusters transmission medium,the depolarization ability is stronger.The research work of this paper provides a new research direction for studying the influencing factors of polarized light in the process of atmospheric transmission,enriches people's cognition of aerosol particles in haze,and has certain reference value for improving the efficiency of polarized light transmission.