Optical Remote Sensing for Characterizing the Spatial Distribution of Stack Emissions

In this contribution, optical methods based on passive FTIR (Fourier Transform Infrared) and DOAS (Differential Optical Absorption Spectroscopy) techniques have been used to characterize the dispersion of gas emissions from industrial sources. Portable, zenith-looking, passive-DOAS instruments measured the horizontal distribution of an SO

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plume from a power plant in a coastal town of Mexico. The column density of this gas was measured while making traversals across the plume with a car and a boat downwind from the emission source. The cross sections measured at different distances from the source are used to characterize the horizontal dispersion and to estimate emission fl uxes. In addition, a Scanning Infrared Gas Imaging System (SIGIS) was used to acquire passive IR spectra at 4 cm

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resolution in a two-dimensional array, from which a false-color image is produced representing the degree of correlation of a specifi c gaseous pollutant. The 24-h, real-time animations of the SO

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plume help us to understand dispersion phenomena in various atmospheric conditions. The wealth of information retrieved from these optical remote sensors provides an alterative method for evaluating the results from plume dispersion models.

Keywords

: Industrial emissions, optical remote sensing, passive DOAS, passive FTIR, plume dispersion