New Technique for Visualizing Three-Dimensional Flow in the Atmospheric Boundary Layer
The atmospheric transmission large-area analysis system (ATLAS) was developed to characterize smokes/obscurants during U. S. Army field tests. Digital image processing of data obtained from a thermal imager allows a two-dimensional map of transmission through the cloud (in a plane perpendicular to the observer’s line of sight) to be obtained. The ambient (natural) background scene in the imager’s field of view is the source against which the transmission measurements are made. The spatial resolution varies depending on the geometry of the test setup; however, X–Z resolution (Y is along the line of sight) of the order of 0. 5 m is easily obtained. The time resolution is 10 Hz. Conversion of these results to concentration is described and the results presented. The technique can be extended to three dimensions by using tomographic analysis.
KeywordsFlow Visualization Thermal Imager High Time Resolution Background Scene Tomographic Analysis
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