July 28, 2010
Sensing Wind Speed With Kites
Kites have a storied history in meteorological research -- think of Benjamin Franklin and his study of electricity -- including being used to carry aloft sensors that measure wind speed. Previously, however, these sensors, because they were exposed to direct sunlight, were prone to temperature errors that affected their accuracy. Now researchers at the University of Reading in the United Kingdom have developed a way to use a kite itself to measure wind speed.
The researchers, professor of atmospheric physics Giles Harrison and applied meteorologist Kieran Walesby, describe their device in the AIP's Review of Scientific Instruments. The instrument consists of a 2-meter-long and 1-meter-wide Rokkaku-type kite -- a simple-to-construct Japanese kite design with "good stability, reasonable load-carrying capacity, and a low sink rate when the wind speed drops," Harrison says -- attached to a ground-based strain gauge that monitors the tension in the kite's tether line. That line tension, Harrison and Walesby found, is linearly related to wind speed.
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