0000000000495711

AUTHOR

Christian Wenger

Simulation de spectres à haute température : une approche statistique du compromis résolution / précision

International audience; Malgré les progrès continus enregistrés dans le domaine de la spectroscopie moléculaire, théorique et expérimentale, les banques de données spectroscopiques disponibles présentent des lacunes importantes, notamment pour l'interprétation des observations des environnements astrophysiques à haute température. Ce constat s'applique en particulier à la molécule de méthane présente dans les atmosphères de nombreux objets astrophysiques. La modélisation du coefficient d'absorption du méthane dans le proche infrarouge et/ou à haute température continue à défier les théoriciens du fait de la complexité intrinsèque de son spectre rovibrationnel. De fait, les analyses à haute …

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The present status of methane spectroscopy for planetary applications

International audience

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SPVIEW and XTDS: graphical tools for the analysis and simulation of high-resolution molecular spectra

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Theoretical Modelling of the Methane Absorption Spectrum for Planetary Applications

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Multi-resolution error analysis of predicted absorption coefficients. Method and computer implementation. Application to the IR spectrum of methane at high temperature.

A general method for the estimation of the confidence interval of molecular absorption coefficients is presented. It combines statistical numerical experiments with analytical calculations. The method uses line parameter predictions (position and intensity) with known estimated uncertainties. The propagation of errors from line parameters to absorption coefficients or cross-sections are analyzed in detail as a function of the resolution. This work is especially intended to provide expert information for applications requiring theoretical predictions for which the present state of the art of line by line high-resolution modeling is not accurate enough to meet the experimental precision. As a…

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The STDS Dijon system : Present status and prospects.

The Dijon spectroscopy group has developed powerful techniques based on group theory and tensorial formalism in order to analyze and simulate absorption and Raman spectra of molecules with various symmetries. Software packages and databases implementing these tools have been created [1]. Compared to the widely used spectroscopic databases (HITRAN, GEISA), these packages, with their XTDS common interface [2], are primarily devoted to the calculation of line parameters and spectra from a database of model parameters. Future developments include improved fitting algorithms, inclusion of C3v symmetric tops, rovibronic couplings, uncertainty estimates. Moreover, calculated line lists will be acc…

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C3v Top Data System (C3vTDS) Software for Spectrum Simulation of XY3Z Symmetric-Top Molecules Using the O(3) ⊃ C∞v ⊃ C3v Group Chain.

International audience

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Etat de l'Art de la Modélisation Théorique du Spectre d'Absorption du Méthane, pour les Applications en Planétologie

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Multi-Resolution error analysis of predicted absorption coefficients. Method and computer implementation. Application to the infrared spectrum of methane at high temperature.

A general method for the estimation of the confidence interval of molecular absorption coefficients is presented. It combines statistical numerical experiments with analytical calculations. The method uses line parameter predictions (position and intensity) with known estimated uncertainties. The propagation of errors from line parameters to absorption coefficients or cross-sections are analyzed in detail as a function of the resolution. This work is especially intended to provide expert information for applications requiring theoretical predictions for which the present state of the art of line by line high-resolution modeling is not accurate enough to meet the experimental precision. As a…

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