A MOBILE ROBUST FTIR FOR PASSIVE FIELD DETERMINATION OF GASEOUS SPECIES
Loading...
Date
1999
Authors
Daum, R.
Beil, A.
Johnson, T. J.
Abraham, B. M.
Journal Title
Journal ISSN
Volume Title
Publisher
Ohio State University
Abstract
Passive remote sensing using an FTIR spectrometer allows the detection and identification of pollutant/toxic gases in the atmosphere. In this paper we report a measurement method and data reduction technique that to not require a previously measured reference spectrum. Recent experimental results obtained using a new high-sensitivity mobile FTIR are presented. After a radiometric calibration of the spectrometer using reference blackbodies, the spectral radiance of the background is determined. Using the inverse function of Planck's radiation law, the brightness temperature $\epsilon(\nu)$ is computed. The temperature spectrum provides a spectrally constant reference for many of the materials used as backdrops in field measurements since their emittance is high and nearly constant in the 800 to $1200 cm^{-1}$ range. Experimental results are presented to illustrate the enhancement of the signal-to-noise ratio that can be achieved by using a backdrop that provides maximal temperature difference to ambient environment.
Description
Author Institution: Bruker Saxonia Analytik