Open AccessA static Fourier transform spectrometer for atmospheric sounding: concept and experimental implementation
Author(s) -
Antoine Lacan,
FrançoisMarie Bréon,
A. Rosak,
Frank Brachet,
Lionel Roucayrol,
Pierre Etcheto,
Christophe Casteras,
Yves Salaün
Publication year - 2010
Publication title -
optics express
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.18.008311
Subject(s) - spectrometer , optics , remote sensing , absorption (acoustics) , fourier transform , fourier transform spectroscopy , atmospheric optics , depth sounding , transmittance , optical path , noise (video) , environmental science , atmospheric sounding , infrared window , imaging spectrometer , computer science , fourier transform infrared spectroscopy , physics , geology , infrared , artificial intelligence , oceanography , quantum mechanics , image (mathematics)
Spaceborne remote sensing can be used to retrieve the atmospheric composition and complement the surface or airborne measurement networks. In recent years, a lot of attention has been placed on the monitoring of carbon dioxide for an estimate of surface fluxes from the observed spatial and temporal gradients of its concentration. Although other techniques may be used to estimate atmospheric CO(2) concentration, the most promising for the near future is the absorption spectroscopy, focusing on the CO(2) absorption lines at 1.6 and/or 2.0 microns. For this objective, the French space agency (CNES) has developed a new spectrometer concept that is sufficiently compact to be placed onboard a microsatellite platform. The principle is that of a Fourier Transform Spectrometer (FTS), although the classical moving mirror is replaced by two sets of mirrors organized in steps. The interferogram is then imaged on a CCD matrix. The concept allows a very high resolving power, although limited to narrow spectral bands, which is well suited for the observation of a few CO(2) absorption lines. The laboratory model shows that a resolving power of about 65000 is achieved with a signal to noise on the spectra around 300. A modulating plate on the light path allows an easy of the path difference. Although this component adds some complexity to the instrument, it greatly improves the information content of the measurements.