Comparative measurements of atmospheric turbulence parameters by optical methods
P.A. Konyaev, V.P. Lukin, V.V. Nosov, E.V. Nosov, E.L. Soin, A.V. Torgaev
V.E. Zuev Institute of Atmospheric Optics of Siberian Branch of the Russian Academy of Science, Tomsk, Russia
Keywords: atmosphere, Kolmogorov turbulence, coherent turbulence, Fried parameter, phase front slope, Navier-Stokes equations
Abstract
Different methods for measuring random wavefront tilts are considered. Possibilities of measuring the Fried parameter by the differential method in turbulence sensing and adaptive optics problems are determined. Comparative measurements of the level of turbulence along a horizontal path were carried out by two optical methods: (1) with a differential turbulence meter and (2) a passive method based on image jitter measurements with a high-speed digital video camera mounted at a small astronomical telescope and real-time processing algorithms. Possible differences in the measurement results are discussed. Patterns of the evolution of the convective motion of a medium inside a volume are derived in terms of the velocity field and scalar temperature and pressure fields on the basis of numerical solution of the system of Navier-Stokes equations. Ways of developing a wavefront sensor which ensures high-precision phase measurements in both Kolmogorov and non-Kolmogorov turbulence are suggested.
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