Statistics of speckle propagation through the turbulent atmosphere

The effect of speckle after laser propagation through a turbulent atmosphere is assessed through use of the Huygens-Fresnel formulation; expressions for the variance, covariance and power spectral density of the beam intensity are developed. Experimental results show that although Gaussian field statistics prevail at the receiver for low turbulence levels, this is not true for the case of intermediate turbulence levels. Accordingly, log-amplitude perturbation effects have been incorporated into the variance, covariance and power density expressions.