Fluctuations of laser beams over urban near-the-ground path

A comparative analysis of the fluctuation structure of laser radiation over urban near-the-ground paths is performed for different turbulent states. The data obtained in experiments allow changes in the statistical characteristics of laser beams, which are induced by aperture effects, to be compared to those caused by changes in the turbulent state of the propagation medium. The influence of intermittency of small-scale turbulence on the radiation characteristics is considered. It is found that the intermittency has a weak effect on the rms shift of the beams' 'centers of gravity' but affects substantially the spatial and temporal intensity fluctuations.