The space‐time intensity correlation function of scintillation due to a deep random phase screen

An investigation of the space‐time correlation function of the electromagnetic radiation scattered by a “deep” random phase screen with Gaussian space correlation function is conducted. The model for the statistics of the phase screen allows for random temporal evolution of the screen and for a steady drift, as well. Using this model, an expression for the space‐time intensity correlation function is derived under the Huygens‐Fresnel approximation. The complete space and time intensity correlation function is evaluated numerically for several examples where the time variation is caused purely by random temporal evolution of the screen. The examples are chosen to illustrate the space‐time properties of scattering in the “non‐Gaussian” regime where the field at a point below the screen is influenced by only a few independent scatterers in the screen.