Distribution of fluctuations of light intensity behind the objective of a telescope after reflection in a turbulent atmosphere

An investigation is made of the behavior of the variance and of the spatial correlation coefficient of the intensity of optical radiation reflected by a turbulent atmosphere as a function of the position of the plane of observation relative to the entrance pupil of the front lens of a telescope. It is shown that enhancement or attentuation of intensity fluctuations in the image plane of the lens, compared with the fluctuations in the plane of the lens itself, is localized in a region which is limited in the longitudinal direction. These effects and the dimensions of the localization region depend on the parameters of the receiving system and the initial coherence of the source field.