Effects of absorption on image quality through a particulate medium.

A new approach to studying the effects of absorption by aerosols and molecular particulates of electromagnetic radiation is presented. In contradiction to the conventional concept that absorption gives rise to constant attenuation, it is shown here that the particulate-absorbed irradiance is spatial frequency dependent. An analytically corrected model of the aerosol modulation transfer function and the aerosol mutual coherence function is presented. An important application of this model is in thermal imaging, in which particulate-absorption effects are very significant.