Study On The Attenuation Characteristics Of Laser Transmission In Fog

When the laser propagates in the atmosphere,it decays due to the absorption and scattering of atmospheric molecules and aerosol particles.Different weather conditions will have different effects on the transmission of space borne laser,especially in the fog environment.In order to analyze the transmission attenuation coefficient of laser,an experimental system of laser transmission attenuation is built.By comparing the attenuation coefficient calculated from the experimental data with that of the classical model,and calculating the root mean square error between them,the applicability of the classical model in Xi'an is analyzed.The specific research contents are as follows:(1)Based on Mie scattering theory,the attenuation characteristics of laser with different wavelengths in fog particles are simulated and analyzed.The commonly used laser attenuation models are introduced,and the attenuation coefficients of different models in fog environment with different visibility are simulated and analyzed.(2)According to the theoretical analysis.Firstly,a short-distance laser link is established to measure and calculate the attenuation coefficient of the laser when the communication distance is 80m and 340m.The variation of attenuation coefficient in fog environment with different visibility is analyzed and compared;Secondly,the long-distance laser link is established to measure and calculate the attenuation coefficient of the laser when the communication distance is 2500 m;The attenuation coefficient is fitted by the least square method,and the fitting curve and the model simulation curve are analyzed and compared.(3)Analyze and compare the attenuation coefficient calculated by the experimental measurement and the attenuation coefficient of the empirical model.By calculating the root mean square error of the two,the applicability of the model is analyzed,and the conclusion is drawn:When the laser wavelength is 650nm and the communication distance is 80m,the attenuation coefficients of the Kruse model and the Kim model are more consistent with the laser attenuation characteristics in Xi'an;When the communication distance is 340m,the attenuation coefficient of the Ijaz model is more in line with the laser attenuation characteristics in Xi'an;When the communication distance is 2500m,the attenuation coefficient of the Kim model is more in line with the laser attenuation characteristics in Xi'an.The conclusion of this paper provides a reference for the attenuation coefficient analysis of wireless optical communication system in Xi 'an area under fog environment.