激光在大气中传输时容易受天气的影响，因为雨、雪、雾等恶劣天气对激光有严重的衰减作用，会使 通信的稳定性变差。因此分析激光在不同天气条件下的传输效应和衰减特性非常有必要。本文根据辐 射雾和平流雾中含水量和能见度的经验关系，分析了雾天气对激光大气传输衰减的计算公式，并对三 种常用的雾衰减经验模型进行了Matlab数值仿真，得出了激光衰减系数和雾天气能见度的关系。

Laser is susceptible to weather when it is propagating in atmosphere. This is because the severe weather including rain, snow and fog has a great attenuation function to laser and may cause the communication to be poor. So, it is necessary to analyze the transmission effect and attenuation characteristics of laser under different weather conditions. According to the experience relations of water content and visibility in radiation fog and advection fog, the formulas for calculating the transmission attenuation of laser in atmosphere under the fog weather condition are analyzed. Three typical empirical models for fog attenuation are simulated numerically by Matlab and the relationship of the visibility in fog with the attenuation coefficient of laser is obtained.