Rejection criteria for open-path Fourier transform infrared spectrometry during continuous atmospheric monitoring

Shao, L. and Pollard, M.J. and Griffiths, P.R. and Westermann, D.T. and Bjorneberg, D.L. (2007) Rejection criteria for open-path Fourier transform infrared spectrometry during continuous atmospheric monitoring. Vibrational Spectroscopy. 43:78-85.

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Abstract

Over 32,000 interferograms measured during open-path Fourier transform infrared (OP/FT-IR) measurements at dairy and hog farms were
evaluated for anomalies. Five types of anomalies could be distinguished: a reduction in the interferogram intensity because of weather-related
optical misalignment; an increase in the amplitude of interferograms measured with too short a path-length that leads to a non-linear detector
response; a periodic interference caused by wind-induced vibrations; the presence of spikes in the interferogram; and an increase in the noise level
of the interferogram (and hence of the spectrum) because of the effect of electrical interference. Prior to testing for the presence of anomalous data,
each interferogram is subjected to a high-pass filter. A noise level index is then calculated from the wings of the interferogram and interferograms
are rejected if the value of this parameter is too high. When the criteria developed in this project are applied, OP/FT-1R spectra may be measured at
1-min intervals over a period of several days.

Item Type:	Article
NWISRL Publication Number:	1217
Subjects:	Research methodology Mass Import - autoclassified (may be erroneous)
Depositing User:	Users 6 not found.
Date Deposited:	20 Nov 2010 21:49
Last Modified:	31 Oct 2016 17:24
Item ID:	55
URI:	https://eprints.nwisrl.ars.usda.gov/id/eprint/55