Characteristics Of Atmospheric Scattering Research For Non-line-of-sight Ultraviolet Light

Atmosphere provides a great deal of security for human survival and development,the study of the atmosphere has been an important content of meteorology and air dynamics research.The principle of laser radar,which is now used to measure the characteristics of air velocity,density,and so on,is to use the backward scattering light of air and to analyze the information of scattered light.For the high content of atmospheric aerosols,we can use the laser wavelength of 10.6?m,2?m,1.06?m to detect it,but for small aerosol content of the atmosphere,we have to detect the laser from the scattering of molecules to calculate some physical quantities.In order to improve the scattering intensity and improve the SNR,we use 266 nm “solar blind” UV as the working wavelength.In this paper,an innovative theoretical study is carried out on the scattering of ultraviolet light in the atmosphere.Using the single scattering model and multiple scattering model,the transmission characteristics of the non-line-of-sight ultraviolet light scattering under different working modes and atmospheric conditions are discussed,and the model is optimized.The main work is as follows:Firstly,based on Rayleigh scattering theory,the relationship between the Rayleigh scattering coefficient and wavelength of specific particles is discussed.According to Mie scattering theory,the influence of aerosol size parameters on Mie scattering coefficient is studied,and the scattering coefficient and the proportion of each scattering are determined according to different atmospheric environment.Secondly,based on the single scattering model,we studied the theory of coplanar and non-coplanar,in the same time we discussed the effect of different communication distance,elevation and half-angle of transmitter and receiver on flux density and energy density detected by the detector.Then the single scattering model is improved and simplified for the coaxial laser radar.The single scattering model is used to analyze the characteristics of the ultraviolet pulse broadening,in the last the link loss is studied.Thirdly,based on multiple scattering models,First of all,we study the Monte Carlo method used to simulate the transmission of photons directly.Then the direct simulation method is improved by pointing probability method.Using the pointing probability method to simulated the effect of different distance,elevation and half-angle of transmitter and receiver and different weather conditions on the results.The simulation results of the single scattering and multiple scattering models are compared,and the advantages and disadvantages of each model are also pointed out.Based on the multiple scattering model,the effect of the deflection angle of the transceiver axis and the molecular scattering ratio on the results is analyzed.The above research is mainly reflected in the impulse response and energy density detected by the detector.By studying the impulse response characteristics and link loss,the characteristics of the scattering of ultraviolet light in the atmosphere are obtained.These studies provide theoretical support for the design of radar detection system,and it has a certain practical reference value.