基于Mie散射理论,给出了利用半解析蒙特卡罗法模拟气溶胶粒子对水平线偏振激光后向散射的主要过程;基于气溶胶和云的光学特性库,选择了4种典型环境、5种典型气溶胶组分和3种湿度条件,分别计算了1.5 μm和2.0 μm波段处后向散射回波的退偏度、偏振度和回波光子数,得到了后向散射光的偏振特性随各组分粒径的变化规律以及各气溶胶环境的后向散射激光回波特性,并分析了不同环境下达到相同探测性能时所需的激光功率比,为远距离高精度相干激光雷达系统的设计和分析提供了参考。

Based on Mie scattering theory, the main process of semi-analytic Monte Carlo simulation is illustrated to research the backscattering properties of aerosol particles to linearly polarized laser in horizontal direction. Four typical environments, five typical aerosol components and three humidity conditions are chosen from optical property libraries of aerosols and clouds. The depolarization ratio, polarization ratio and returned photon number are calculated at 1.5 μm and 2.0 μm, respectively. The variation laws of polarization properties of backscattered laser are acquired with changing of particle sizes of different kinds of aerosol components. Besides, the echoing characteristics of backscattered laser are obtained in four typical aerosol environments. At last, the laser power ratio needed in different environments to achieve the same detection performance is analyzed, which is of reference value to the design and analysis of the coherent lidar systems for the long range and high accuracy observation.