Understanding the Influence of Turbulence in Imaging Fourier-Transform Spectrometry of Smokestack Plumes
Date of Award
Master of Science
Department of Engineering Physics
Kevin C. Gross, PhD.
An imaging Fourier-transform spectrometer (IFTS) was used to collect infrared hyper-spectral imagery of smokestack plume of a coal-burning power facility to assess the influence of turbulence on spectral retrieval of temperature (T) and pollutant concentrations (Ci). Radiance fluctuations due to plume turbulence introduced scene change artifacts (SCA) in the spectra. Time-averaging the spectra minimizes SCA magnitudes, but accurate T and Ci retrieval would require a priori knowledge of the statistical distribution of temperature and other stochastic flow field parameters. A method of quantile sorting in interferogram space that would allow the retrieval of the temperature distribution is presented and used to identify turbulence throughout the plume. Immediately above the stack exit, T and Ci estimates compared well to in situ measurements, and turbulence introduced only small systematic errors. Systematic errors, however, were more significant in other parts of the plume. While more complicated radiance fluctuations precluded retrieval of the temperature distribution, the results demonstrate the utility of additional information associated with interferogram quantiles and suggest the utility of IFTS in non-intrusive flow field analysis.
DTIC Accession Number
Massman, Jennifer L., "Understanding the Influence of Turbulence in Imaging Fourier-Transform Spectrometry of Smokestack Plumes" (2011). Theses and Dissertations. 1462.