I-K distribution as a universal propagation model of laser beams in atmospheric turbulence

A new propagation model is developed for the intensity fluctuations of a laser beam propagating through extended clear-air turbulence. The field of the optical wave is modeled as the sum of a coherent (deterministic) component and a random component, the intensity of which is assumed governed by the generalized n distribution of Nakagami. It is further assumed that the statistics are inherently nonstationary by treating the average intensity of the random portion of the field as a fluctuating quantity. The resulting unconditional I-K distribution for the intensity fluctuations is a generalized form of the K distribution that is applicable to all conditions of atmospheric turbulence for which data have been obtained, including weak turbulence for which the K distribution is not theoretically applicable.