Libraries

Because we seek to make maximal use of the information in the rotational signatures, we need reference libraries such that the noise and clutter in the spectra of the sensor spectra dominate the recovery process. While it is true that the spectrum of a species is in general redundant, analysis procedures that in effect subtract overlapping lines require knowledge of the spectra at every frequency used for the analysis of a mixture, not just at the best fingerprint regions of each analyte. Moreover, because many low lying vibrational states of even common molecules have not been analyzed and included in catalogs, spectral libraries based on quantum mechanical calculations from these constants can be massively incomplete [1]. This, combined with the aforementioned Doppler linewidths, resulted in libraries that are useful on any similarly calibrated instrument.