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Indexed by:期刊论文

Date of Publication:2013-06-01

Journal:OPTICS AND LASER TECHNOLOGY

Included Journals:SCIE、EI、Scopus

Volume:48

Page Number:580-588

ISSN No.:0030-3992

Key Words:Photoacoustic spectroscopy; Feature extraction; Overcomplete ICA bases

Abstract:In near-infrared band, macro representations of rovibrational-transition absorptions of some low molecule mass gases are "spiky" transient lines. The pressure broadening at ambient temperature and pressure make lineshape profiles at adjacent wavelength produce mutual projection or superposition, and it makes the "spiky" absorption features just be hidden in observable spectra. A blind source separation (BSS) model can extract features which hide within sampled spectra data, if a mixed gas phase photoacoustic signal is regarded as the weighted sum of feature absorptions by the spacing between adjacent feature wavelengths. A BSS model based on overcomplete ICA basis is proposed, and a weight truncation equation for transforming ICA bases based on the five-point sampling method is created so that a FastICA algorithm based on a negentropy approximation can be used to extract feature components. The resulting validity test using data from a real-time experiment of gas detection showed that the method detection limit can be improved from 16 ppb to 10 ppb with improved accuracy and signal-to-noise ratio. Crown Copyright (C) 2012 Published by Elsevier Ltd. All rights reserved.