Applying Photogrammetric Techniques to Study Smoke Plumes

Still photography of a contaminant release provides valuable information about the atmospheric transport and dispersion of a contaminant. We study the dispersion of a series smoke plumes over time and use photographs to derive various plume characterization parameters including optical depth, opacity, and concentration values. A photogrammetric method is devised that uses calibrated cameras to compare smoke plume measurements relative to both black and white backgrounds. The opacity of the plume at various points in time and space is determined by the intensity of the pixel value in a given image. In addition, analysis of light source transmission through the plume allows for computation of aerosol optical depth. Finally, measurements with a radiometer provide spectral characterization of the plumes. These data can be used to derive concentration amounts and a three dimensional reconstruction of the plume is possible. These measurements along with corresponding videos provide a full four-dimensional characterization of the smoke plumes and allow comparison of several realizations under similar meteorological conditions. We compare the actual plumes to modeled plumes and the realizations to an ensemble average. Experiments are conducted at Penn State's Rock Springs, PA testing site.