Improved strategies for quantitative evaluation of atmospheric FTIR spectra obtained in open-path monitoring

Improvements in the quantitative evaluation of atmospheric Fourier-transfor m infrared (FTIR) spectra, obtained in environmental monitoring by using a bistatic spectrometer setup, are presented, Preprocessing of interferograms and spectral data was carried out to improve the photometric accuracy and wave-number scale reproducibility, necessary for reliable quantitative anal ysis. Univariate component analysis was optimized, and a refined strategy f or multivariate analysis by least squares was set up, Special procedures we re developed for the determination of benzene and of small molecules with r esolved rotation-vibration fine structure. Results from field measurements, which were obtained by using the implemented subroutines for univariate an d multivariate spectrum evaluation, are presented and discussed. (C) 1999 J ohn Wiley & Sons, Inc.