Amplitude fluctuations of a plane wave in a random medium with regular refraction in the Markov-process approximation

The fluctuations of a ray vector and the wave amplitude along the ray in a random medium with regular refraction are considered in a geometric-optics approximation. The solution of the problem is based on the description of the scattering process by Langevin-type stochastic dynamic equations. Under the assumption that the correlation radius of dielectric permittivity fluctuations is small compared with the distance passed by a ray, one can consider scattering as a Markov process and pass from dynamic equations to the Einstein-Fokker equation [1]. A solution to the Einstein-Fokker equation is given by the probability density function of the wave amplitude along the ray.