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Proceedings Paper

Chemical detection and classification in Raman spectra
Author(s): Steven Kay; Cuichun Xu; Darren Emge
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Paper Abstract

Because of the unique Raman spectrum of a chemical, Raman spectroscopy can be used to identify chemicals on a surface. In this paper chemical detection and classification in a stationary background are addressed. Firstly, because the autoregressive (AR) spectrum is capable of representing a wide range of spectra, both the pure background and background plus a chemical are modeled as AR spectra with different coefficients. Based on this modeling, a generalized likelihood ratio test (GLRT) is proposed to detect abnormal chemicals in the background. In essence, the GLRT detector tests if the data can be represented by a known AR background spectrum. With the AR spectrum modeling, a classifier based on the locally most powerful test is also proposed to classify the detected chemicals. Computer simulation results are given, which show the effectiveness of the proposed algorithms. Practical problems, such as setting the detection threshold, extension to nonstationary backgrounds, and the identifiability of chemicals are also discussed.

Paper Details

Date Published: 16 April 2008
PDF: 12 pages
Proc. SPIE 6969, Signal and Data Processing of Small Targets 2008, 696904 (16 April 2008); doi: 10.1117/12.784622
Show Author Affiliations
Steven Kay, Univ. of Rhode Island (United States)
Cuichun Xu, Univ. of Rhode Island (United States)
Darren Emge, U.S. Army Edgewood Chemical Biological Ctr. (United States)

Published in SPIE Proceedings Vol. 6969:
Signal and Data Processing of Small Targets 2008
Oliver E. Drummond, Editor(s)

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