【摘要】 激光在自由空间进行传输时,受大气分子和气溶胶粒子的影响,发生的后向散射效应会降低激光传输系统的可靠性,研究激光在大气中传输的后向散射效应,可以有效提高激光通信系统的安全性和保密性。利用蒙特卡罗(Monte Carlo)方法对大气后向散射信道特性进行分析,建立了激光在大气中传输的后向散射理论模型,为了提高蒙特卡罗算法的计算效率,在原模型的基础上提出了一种改进的快速蒙特卡罗方法,分析了能见度、非对称因子以及介质反照率对后向散射能量的影响,利用MATLAB进行了仿真模拟分析,得出后向散射能量随能见度、非对称因子以及介质反照率的变化规律,结果表明该方法可以准确和快速地计算后向散射能量,并为激光通信系统的设计提供了依据。更多还原

【Abstract】 When the laser is transmitted in free space, the backscattering effect will reduce the reliability of the laser transmission system due to the influence of atmospheric molecules and aerosol particles. Studying the backscattering effect of laser transmission in the atmosphere can effectively improve the security and confidentiality of laser communication system. In this paper, the characteristics of atmospheric backscattering channel are analyzed by Monte Carlo method, and the backscattering model of laser propagation in the atmosphere is established. In order to improve the efficiency of Monte Carlo algorithm, an improved fast Monte Carlo method is proposed based on the original model. The variation of backscattering energy with visibility, asymmetry factor and medium albedo is obtained by MATLAB, and the simulation results show that this method can estimate backscattering energy accurately and quickly, which effectively points out directions for the design of the laser transmission system.更多还原