Research On Transmission Characteristics Of Laser Under Complex Atmospheric Background

This paper focuses on transmission characteristics of laser under the complex atmospheric background. Firstly, the basic physical characteristics of cloud and fog are presented. Then using Mie theory and size distribution of particles, light scattering by two models of fog is achieved. The volume scattering characteristics under different wavelengths are compared. The scattering characteristics of single hexagonal ice crystal are calculated by anomalous diffraction theory, and the results are compared with those by Mie theory of the equivalent sphere.Based on transmission theory, comparisons of results by the first-order multiple scattering approximation and Monte Carlo method are discussed. The attenuation and backscattering characteristics of laser through low visibility fog are studied with Monte Carlo method. The attenuation ratio and the reflectivity of laser through fog are fitted as empirical formula. When Lambert surface and mirror face exist in fog, backscattering characteristics of laser are developed with four-flux model and MC met. The simulation of light scattering of surface is given, and a simple experience model is dealt with.The problem of polarized light transfer in atmosphere is studied at the end of this paper. Some basic conceptions and simulation process are introduced. Then the relationship between the depolarization characteristics of fog with visibility and transfer distance is studied.