MEASURED STATISTICS OF LASER-LIGHT SCATTERING IN ATMOSPHERIC-TURBULENCE

The statistical properties associated with the intensity fluctuations of a He-Ne laser beam propagating through extended clear-air turbulence over a homogeneous range were measured and compared with existing theoretical models. The statistics were determined by measuring the first five normalized moments of the beam intensity over varying distances from 183 m to 3 km. The beam geometry was approximately that of a spherical wave. The data obtained correspond to many conditions of turbulence from weak to strong turbulence in the saturation regime. It is found that the data generally support the lognormal model under conditions of weak turbulence and the negative-exponential distribution in the superstrong-turbulence regime.