Some New Developments in Atmospheric Turbulence and Terrain Surface Description

Abstract

Atmospheric turbulence spectra follow either the von Karman formula or a modified form of the Lappe/Lockheed-Georgia equation. The integral scale parameter is not only a turbuilence concept but a basic parameter common to all stationary stochastic processes. Because of the finite measuring base length, the standard deviation of the turbulence a calculated directly from flight records is always less than the theoretical value in the spectrum formulae. Spatial spectra can be directly transformed into time spectra by calculation of the time scale. Bulk processing of long flight records is inadvisable becasue of the limited lengths of the homogeneous sections in atmospheric turbulence. Runway-respective grass airfield surface spectra follow closely the modified Lockheed-Georgia equation with the exception of the exponent being a third parameter to be measured individually.