Measuring the turbulence profile in the lower atmospheric boundary layer.

Optical turbulence can have a severe effect on the propagation of laser beams through the atmosphere. In free space optics and directed energy applications, these laser beams quite often propagate along a slant or vertical path. In these cases, the refractive index structure function parameter cannot be assumed constant, since it varies with height.

Evolution of near-ground optical turbulence over concrete runway throughout multiple days in summer and winter.

Experimental data are presented that demonstrate the evolution of the anisotropy/isotropy of atmospheric statistics throughout the course of four days (two winter, two summer) near the ground over a concrete runway in Florida. In late January and early February of 2017, a 532 nm near-plane-wave beam was propagated 1 and 2 km at a height of 2 m above the runway, and irradiance fluctuations were captured on a CCD array. In August of 2017, a 532 nm Gaussian beam was propagated 100 m at a height of near 2 m, and fluctuation data were captured on a CCD array.

Near ground measure and theoretical model of plane wave covariance of intensity in anisotropic turbulence.

Experimental measurements were recently made which displayed characteristics of plane wave propagation through anisotropic optical turbulence. A near-plane wave beam was propagated a distance of 1 and 2 km at a height of 2 m above the concrete runway at the Shuttle Landing Facility, Kennedy Space Center, Florida, during January and February of 2017. The spatial-temporal fluctuations of the beam were recorded, and the covariance of intensity was calculated.