A characteristic nondimensional distortion number Nd was derived in the 1970s that allows inference of the degree of nonlinear refraction or thermal blooming associated with an atmospheric laser path. For a continuous-wave (CW) laser with a Gaussian-shaped beam, the distortion number is a function of several variables including laser power and aperture size, optical wavelength, atmospheric absorption and extinction, index of refraction, temperature, air density, and the air speed or ...
The atmosphere can have a tremendous impact on tactical high-energy laser (HEL) systems. The variable nature of the atmosphere can produce highly variable performance. System designers need accurate environmental models to optimize the design of these systems. This paper reviews the atmospheric impact of various atmospheric phenomena on laser performance and the measurement and modeling efforts of the Air Force Research Laboratory. Two of these phenomena, optical turbulence and cloud ...
The Space Vehicles Directorate, in collaboration with the Airborne Laser (ABL) Program Office collected data in the measurement and understanding of atmospheric optical turbulence. Optical turbulence, or fluctuations of the index of refraction in both space and time, is not only apparent in twinkling stars, but is also a major source of performance degradation for high-energy laser systems. Optical turbulence is caused by the presence of adjacent parcels of air, ...
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