Spectral Searching by Fourier-Phase Correlation

Abstract

A new idea of spectral library searching is proposed, in which only the phase components of Fourier transforms of both the sample and the reference spectra are used for spectral identification. Compared with the conventional methods, this method has essentially a very high discrimination ability for distinguishing between similar spectra and is very resistant to the peak-height variation and the peak-position shift due to the experimental conditions. The principle and the algorithm of this library search method are described, along with the experimental results for infrared absorption spectra. The results demonstrate that the proposed method gives much lower scores for wrong reference spectra than does the ordinary correlation method, and gives high scores for the sample spectra measured by the various slit widths of the spectrophotometer.