雾和气溶胶前向散射对消光的影响

光电工程中探测器接收的光强包括透射光和大气前向散射光。雾和大气气溶胶粒子的前向散射增强了透射光,从而导致测量的衰减比实际衰减小。本文采用Mie散射理论,根据气溶胶谱分布以及雾滴的谱分布模型及其与能见度的经验关系,计算了可见光到中波红外波长的前向散射修正因子。详细分析了激光在气溶胶和雾衰减中前向散射修正因子随粒子平均半径、能见度和波长等参数的变化关系,并拟合出前向散射修正因子随粒子平均半径和视场乘积的经验关系式,在10°视场内平均残差小于0.02,可为相关光电工程提供参考。

Influence of fog and aerosol particles' forward-scattering on light extinction

In opto-electronic engineering, the light intensity received by the detector includes transmitted light and forward-scattered light. Fog and atmospheric aerosol particles' forward-scattered light increases the transmission, resulting in a measured extinction that is lower than the real amount. Using the Mie scattering theory, based on the atmospheric aerosol particles' size distribution function and an empirical relationship between water content and visibility in fog, the correction factor (CF) of forward-scattering for the extinction of wavelengths in the visible to middle-infrared region was calculated. The influence of parameters such as effective radius, visibility, and wavelength on the forward-scattering CF was discussed in detail. An empirical relationship between the CF and the product of the Field-of-View (FOV) and size parameter was fitted out based on the calculated results, and the mean residual is less than 0.02. The results may be applied in related engineering programs.