OSA's Digital Library

Applied Optics

Applied Optics


  • Vol. 38, Iss. 30 — Oct. 20, 1999
  • pp: 6398–6407

Effects of a nonlinear response of the Fourier-transform infrared open-path instrument on the measurements of some atmospheric gases

George M. Russwurm and Bill Phillips  »View Author Affiliations

Applied Optics, Vol. 38, Issue 30, pp. 6398-6407 (1999)

View Full Text Article

Enhanced HTML    Acrobat PDF (265 KB)

Browse Journals / Lookup Meetings

Browse by Journal and Year


Lookup Conference Papers

Close Browse Journals / Lookup Meetings

Article Tools



The response of a Fourier-transform infrared (FTIR) instrument to changes in absorbance is inherently nonlinear for a number of reasons. One is that the interferogram acquired by the FTIR is truncated and then apodized before further processing of the data is accomplished. A commonly used apodization function in open-path FTIR research is triangular apodization, and all the research presented here has been done with that function. We calculated a set of absorption spectra by using the HITRAN database, covering ranges in both concentration and temperature for water, ammonia, and methane. Plots of these data reveal nonlinear results. The commonly used analysis technique, classical least squares, assumes that the response is linear. We describe some of the effects of this nonlinearity and present ways to address these effects.

© 1999 Optical Society of America

OCIS Codes
(280.1120) Remote sensing and sensors : Air pollution monitoring
(300.6300) Spectroscopy : Spectroscopy, Fourier transforms

Original Manuscript: February 1, 1999
Revised Manuscript: June 25, 1999
Published: October 20, 1999

George M. Russwurm and Bill Phillips, "Effects of a nonlinear response of the Fourier-transform infrared open-path instrument on the measurements of some atmospheric gases," Appl. Opt. 38, 6398-6407 (1999)

Sort:  Author  |  Year  |  Journal  |  Reset  


  1. R. L. Spellicy, W. L. Crow, J. A. Draves, W. F. Buchholtz, W. F. Herget, “Spectroscopic remote sensing addressing requirements of the Clean Air Act,” Spectroscopy 6, 24–34 (1991).
  2. P. R. Griffiths, R. L. Richardson, D. Qin, C. Zhu, “Open path atmospheric monitoring with a low resolution FT-IR spectrometer,” in Optical Sensing for Environmental and Process Monitoring, O. A. Simpson, ed., Proc. SPIE2365, 274–284 (1995). [CrossRef]
  3. P. M. Chu, F. R. Guenther, G. C. Rhoderick, W. J. Lafferty, “The NIST quantitative database,” J. Res. Natl. Inst. Stand. Technol. 104, 59–81 (1999). [CrossRef]
  4. P. M. Chu, National Institute of Standards and Technology, Gaithersburg, Md. 20899 (personal communication, 1999).
  5. The U.S. Air Force Geophysics Laboratory HITRAN molecular absorption parameters database. See, for example, L. S. Rothman, R. R. Gamache, A. Goldman, R. A. Toth, H. M. Pickett, R. L. Poynter, J. M. Flaud, C. Camy-Peyret, A. Barbe, N. Hussen, C. P. Rinsland, M. A. H. Smith, “The HITRAN database: 1986 edition,” Appl. Opt. 26, 4058–4096 (1987).
  6. H. Happ, L. Genzel, “Interfernz-Modulation mit monochromatischen millimeter-wellen,” Infrared Phys. 1, 39–48 (1961). [CrossRef]
  7. A. S. Filler, “Apodization and interpolation in Fourier-transform spectroscopy,” J. Opt. Soc. Am. 54, 762–767 (1964). [CrossRef]
  8. R. H. Norton, R. Beer, “New apodizing functions for Fourier spectrometry,” J. Opt. Soc. Am. 66, 259–264 (1976). [CrossRef]
  9. J. K. Kauppinen, D. J. Moffatt, D. G. Cameron, H. H. Mantsch, “Noise in Fourier self-deconvolution,” Appl. Opt. 20, 1866–1879 (1981). [CrossRef] [PubMed]
  10. G. M. Russwurm, J. W. Childers, FT-IR Open-Path Monitoring Guidance Document, 2nd. ed. SP-4420-95-04 (ManTech Environmental Technology, Inc., Research Triangle Park, N.C., 1995).
  11. G. M. Russwurm, “Compendium method TO-16: long-path open-path Fourier transform infrared method monitoring of atmospheric gases,” in Compendium of Methods for the Determination of Toxic Organic Compounds in Ambient Air, 2nd ed., EPA/625/R-96/010b (U.S. Environmental Protection Agency, Research Triangle Park, N.C., 1996), pp. 16-1–16-42.
  12. A. Ropertz, “Kalibrierung eines FTIR langwegabsorptions-Spektrometeres in Verbindung mit einer einstelbaren Infrarot-Multi-Reflexionsgaszelle und Validerung der Ergebnisse wahrend einer Messkampagne bei einer Raffinerie” (Diplomatarbeit im Fachbereich Maschienen und Vefahrenstechnik an der Fachhochschule Dusseldorf, Matrikel-Nr 240415, Dusseldorf, 1997).

Cited By

Alert me when this paper is cited

OSA is able to provide readers links to articles that cite this paper by participating in CrossRef's Cited-By Linking service. CrossRef includes content from more than 3000 publishers and societies. In addition to listing OSA journal articles that cite this paper, citing articles from other participating publishers will also be listed.

« Previous Article  |  Next Article »

OSA is a member of CrossRef.

CrossCheck Deposited