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The primary purpose of this interdisciplinary paper is to open a dialogue between meteorologists and the experts in SPIE on high-speed photogrammetry. We summarize some of the truths and half-truths conveyed by the recent blockbuster movie 'Twister.' Attempts by the meteorological community over the past 25 years to probe tornadoes and related convective vortices like dust-devils and waterspouts are summarized, with special emphasis on windspeeds near the ground. Photogrammetric estimates made by tracking debris elements and other tracers in eyewitness tornado movies yield peak values as high as 250 - 285 mph; however, there remains much uncertainty about both the accuracy and representativeness of these estimates. We believe that new digital hardware and software for image processing and photogrammetry might yield more reliable tornado windspeed estimates, if our two communities can work together; in fact, multiple simultaneous videos of a debris-laden tornado during the 1995 Vortex field project offer the prospect of 3D photogrammetric windfield synthesis.© (1997) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only. |
