Light extinction in polydisperse particulate systems

Analytic methods are developed for determining the attenuation characteristics of light beams propagating through ensembles of scattering particles including those with complex index of refraction. The methods are applicable to a wide range of practical particulate systems, and the results are expressed explicitly in terms of elementary functions. Propagation through fog and clouds is considered as an example, and it is found that absorption by the liquid lengths. water in such ensembles affects strongly the extinction for ir wave-lengths.