Optical detection of laser or scattered radiation transmitted through the turbulent atmosphere.

Photoelectron counting distributions are obtained for radiation, consisting of a coherent and a chaotic component, after passage through the turbulent atmosphere. Independent additive background radiation is also taken into account. The counting distributions broaden markedly, and their peak occurs at decreasing count numbers for increasing turbulence. Plots of the distributions are presented for various levels of turbulence and various values of the coherent-to-chaotic average irradiance ratio. The results are related to the continuous photocurrent probability density.