A closed set of three simultaneous partial differential equations is derived for the solution of the average irradiance and the irradiance variance of focused laser beams in turbulence. The equations are uniformly valid for arbitrary scintillation levels. Examples of solutions calculated by finite difference techniques are shown to fit typical atmospheric and laboratory data well. Analytic solutions derived for asymptotic conditions are in good agreement with the related classic perturbation results. The model also provides interesting physical insight into the phenomena of saturation and supersaturation.
L. R. Bissonnette, "Propagation model of laser beams in turbulence," J. Opt. Soc. Am. 73, 262-268 (1983)