激光在近地大气降雨环境中传输时, 易被雨滴散射和吸收, 研究不同降雨条件下激光透过特性, 为激光探测在目标探测系统中克服降雨因素的影响提供了一定依据。在Mie散射光学理论基础上, 以韦布分布为雨滴尺寸分布模型, 计算激光波束在雨中的传输衰减特性在降雨量不同时随距离的变化关系, 分析在不同传输距离上5种典型降雨量对激光在水平传输路径上的衰减影响, 并利用Modtran软件计算结果验证该计算结果的正确性。研究表明, 激光透过率随着降雨量以及传输距离的增加而下降, 且降雨量越大, 在一定传输距离上下降速度越快。这些结论为目标探测系统在不同降雨环境中发射系统功率与接收系统精度的选择提供了一定的理论依据。

Laser is easily scattered and absorbed by raindrops when transmitting in the near-Earth rainy environment, so the analysis on laser transmission characteristics under different rainfall provides a certain basis for laser detection to overcome the influence of rainfall factors in target detection system.Based on Mie scattering and geometrical optics theory, Webb distribution as the raindrop size distribution bmodel, the change of laser attenuation with different transmission distance at different rainfalls was calculated. The model is simulated by Modtran to verify the correctness. Studies have shown that with the increase of rainfall intensity and transmission distance, the laser transmittance decreases, and the greater the intensity of rainfall fell, the laser transmittance decline faster in a certain transmission distance. These conclusions provide a theoretical basis for the selection of transmitting system power and receiving system accuracy for target detection system in different rainfall environments.