Share Email Print

Proceedings Paper

NIR spectroscopy with multivariate calibration and lock-in amplification to detect chemicals concealed behind fabrics
Author(s): Aamer Saleem; Céline Canal; David A. Hutchins; Roger J. Green
Format Member Price Non-Member Price
PDF $14.40 $18.00
cover GOOD NEWS! Your organization subscribes to the SPIE Digital Library. You may be able to download this paper for free. Check Access

Paper Abstract

The detection of specific chemicals when concealed behind a layer of clothing is reported using near infrared (NIR) spectroscopy. Concealment modifies the spectrum of a particular chemical when recorded at stand-off ranges of three meters in a diffuse reflection experiment. The subsequent analysis to identify a particular chemical has involved employing calibration models such as principal component regression (PCR) and partial least squares regression (PLSR). Additionally, detection has been attempted with good results using neural networks. The latter technique serves to overcome nonlinearities in the calibration/training dataset, affording more robust modelling. Finally, lock-in amplification of spectral data collected in through-transmission arrangement has been shown to allow detection at SNR as low as -60dB. The work has been shown to both allow detection of specific chemicals concealed behind a single intervening layer of fabric material, and to estimate the concentration of certain liquids.

Paper Details

Date Published: 3 June 2011
PDF: 18 pages
Proc. SPIE 8018, Chemical, Biological, Radiological, Nuclear, and Explosives (CBRNE) Sensing XII, 80181I (3 June 2011); doi: 10.1117/12.883839
Show Author Affiliations
Aamer Saleem, The Univ. of Warwick (United Kingdom)
Céline Canal, The Univ. of Warwick (United Kingdom)
David A. Hutchins, The Univ. of Warwick (United Kingdom)
Roger J. Green, The Univ. of Warwick (United Kingdom)

Published in SPIE Proceedings Vol. 8018:
Chemical, Biological, Radiological, Nuclear, and Explosives (CBRNE) Sensing XII
Augustus W. Fountain; Patrick J. Gardner, Editor(s)

© SPIE. Terms of Use
Back to Top