Stereo passive remote sensing of aerosol transport and diffusion

Atmospheric aerosol transport and diffusion in the planetary boundary layer is characterized by high spatial and temporal variability. Point and single line of sight sensors provide insufficient information necessary for detailed evaluation of aerosol transport and diffusion models, for detecting the trajectory of hazardous material releases, or measurement of environmental pollution. A stereo passive remote sensing system providing detailed smoke screen transport and diffusion measurements during U.S. Army field tests offers extensive aerosol transport and diffusion measurement capability. The system uses digital image processing of thermal image data to provide a pixel by pixel two-dimensional map (perpendicular to the observers line of sight) of transmission or path integrated concentration. The ambient (natural) background scene in the imager field of view is the radiometric source against which transmission measurements are made. Additionally, the system uses sets of multispectral imagers in stereo pairs to obtain generalized three dimensional descriptions of smoke screen transport and diffusion. These data are used to compute the path taken by the centroid of the smoke screen and overall cloud dimensions as a function of time. Time resolution for the system is 10 Hz. The ability of the system to provide three dimensional aerosol transport and diffusion data and path integrated aerosol concentration maps with sufficient sensitivity to evaluate transport and diffusion models in detail, and to detect hazardous material trajectories and environmental pollution is demonstrated analytically and experimentally