Spectroscopie quantitative dans un contexte planétologique
: Influence de la pression sur la bande 21102-00001 à 3 microns du dioxyde de carbone

Translated title of the thesis: Quantitative spectroscopy in a planetology context: Pressure influence on the 21102-00001 band near 3 microns of the carbon dioxyde

Student thesis: Master typesMaster in Physics


The SOIR ("Solar Occultation in the InfraRed") spectrometer, on board the "Venus Express" space probe orbiting Venus, is studying the chemical composition of the atmosphere of this planet via solar occultations in the infrared range (2.3-4.2 microns). To analyze the recorded spectra, the spectral signatures of the various compounds present must be precisely characterized. This work aims to measure parameters characterizing the effects of pressure on the absorption spectrum of the 21102-00001 band of CO2, observed near 3340 cm-1. Accordingly, the absorption spectrum of that vibrational band has been recorded in the laboratory using a Fourier transform spectrometer, at carbon dioxide pressures between 48 and 821 hPa. We analyzed these spectra, considering that the profile of the absorption lines of CO2 could be described by a Voigt function (and a Rautian function for the lowest pressure spectrum). Even if it appeared that these functions only provide an approximate description of the observed line profiles, the parameters characterizing the pressure broadening and pressure shift of the CO2 absorption lines have been determined. Furthermore, the influence of line mixing on the determination of the pressure shifts of the lines was studied.
Date of Award28 May 2013
Original languageFrench
Awarding Institution
  • Université Libre de Bruxelles
SupervisorJean Vander Auwera (Supervisor), Mustapha Tlidi (Jury) & Michel Herman (Jury)


  • carbon dioxyde
  • infrared spectrometry
  • pressure broadening
  • pressure shift
  • venus atmosphere

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