METHOD AND APPARATUS FOR IDENTIFYING A SUBSTANCE USING A SPECTRAL LIBRARY DATABASE

摘要

A spectroscopic detector for identifying the presence of a substance includes a laser for illuminating the substance with electromagnetic radiation at a plurality of wavelengths to induce the emission of radiation characteristic of the substance; a spectrometer or photometer for measuring the emitted radiation at a plurality of emission wavelengths to obtain a plurality of spectral measurement data; and a processor for processing the spectral measurement data. The processor includes a processing algorithm configured for combining the plurality of spectral measurement data into a composite spectrum; and applying the algorithm to the composite spectrum whereby at least one parameter characteristic of the substance is identified while information in the composite spectrum contributed by an emission of radiation from any other substance is removed to thereby identify the presence of the substance, and thereby obtain a characteristic spectral signature of the substance. The signature may then be compared to spectral signatures of substances in a spectral library database. Some of the library spectral signatures may have spectral characteristics differentiated from each other by identifiable spectral characteristics caused by one or more environmental factors.