Propagation Properties Of Sunlight Polarized Radiation In The Earth-atmosphere System

Earth-atmosphere system refers to the earth’s surface and the atmosphere as a whole. After the light of the sun entering the system, a relatively stable atmospheric polarization pattern is formed in the certain area because of scattering effect with the trace gases, aerosol particles and cloud particles, as well as reflecting effect by different surface. The pattern are rich in polarization information, have significant use in the many fields, such as polarization navigation, remote sensing and target detection and so on.This paper using plane-parallel atmospheric structure to construct the structural model of the Earth-atmosphere system, and using the Monte Carlo method to construct Earth-atmosphere system polarized radiative transfer model. Simulated and analyzed the characteristics of Polarized radiation transmission when the sunlight passing the system.The main works in this thesis is as following:1. Using data provided by the OPAC database and basing on plane-parallel atmospheric physical model, we construct a complete structural model of the Earth-atmosphere system. In the model, trace gases in the atmosphere as a background, and the atmosphere is divided into ice clouds layer, water clouds layer, aerosol layer in the vertical direction, and get reflected light polarization properties reflected by different surface according to the surface reflection model;2. Improved radiative transfer model based on the Monte Carlo method by increasing scatter type selection and surface reflection,get the completely Earth-atmosphere system polarized radiative transfer model, and verify the correctness of the model;3. Based on the Structural model and the transmission model of the Earth-atmosphere system, we simulated atmospheric polarization pattern under ideal conditions, and then comparative analyzed the changing of stokes vector and polarization pattern when the sunlight passing the clouds and aerosols;4. After get the sunlight’s polarization characteristics through the single media, and further we simulated and analyzed the change of the polarization characteristics under the weather of cloudy and haze. From the perspective of multi-factors, simulated and analyzed the change of the polarization characteristics at different viewing angles and different wavelength of incident light.