Take-Off and Landing Critical Atmospheric Turbulence (TOLCAT) - Experiments and Analysis.
Final technical rept. Nov 69-Oct 71,
BATTELLE MEMORIAL INST RICHLAND WASH PACIFIC NORTHWEST LABS
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Measurements of turbulence were made from various arrays of tower mounted sensors to demonstrate methods of describing the temporal and spatial character of turbulence. Measurement and data reduction techniques for sonic and three-propeller anemometers were optimized to assure true and accurate measurements of the vertical and two horizontal wind components. Both analog and digital magnetic tape field recording options were demonstrated to provide flexibility in measurement array configurations and to optimize recording capabilities for a variety of measurement requirements. Probability density functions, both individual and joint, were calculated for any pair of wind component variables, oriented in a preselected coordinate system, and optionally high pass filtered for various aircraft response applications. Power spectra of each time series and cross spectra for different wind components at the same point and for the same component at different points were calculated for time series optionally tapered or detrended. Plots of the space-time dependence of correlation functions were obtained from turbulence measurements taken from a logarithmically spaced line of towers, offering a means of determining the turbulence spectra for a given wind component encountered by an aircraft flying through a field of turbulence at a given wind speed. Author