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INTERFEROGRAM-BASED INFRARED SEARCH SYSTEM
Citation:
Haseth, J. AND L. Azarraga. INTERFEROGRAM-BASED INFRARED SEARCH SYSTEM. U.S. Environmental Protection Agency, Washington, D.C., EPA/600/J-81/548 (NTIS PB82205865), 1981.
Description:
A computerized search routine for the identification of infrared spectra using interferometric data exclusively is described. Two forms of instrument-dependent information present in raw interferometric data are removed prior to the search process. Interferometric phase error is removed by a convolution process. The instrument function is eliminated by vector subtraction. The search routine was applied to several target compounds using a collection of 3300 infrared vapor-phase interferograms maintained at the U.S. Environmental Protection Agency's Environmental Research Laboratory in Athens, GA. Even by using a primitive matching algorithm for searching 'unknowns' within the library, excellent results were obtained. In all cases the target compounds were perfectly matched, as expected for an internal library search; however, all the nonexact matches were well distinguished from the exact match and in all cases were structurally similar to the target compound. The capability to locate erroneous entries in the library is demonstrated.