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Caractérisation de la neige, du névé et de la glace par traitement d'images

Abstract : From satellite remote sensing, global and repetitive measurements of the ice sheets are available. Inversion tools are necessary to get the snow mantle charactelistics (snow grain size, density, ... ) from those measurements. For modelling and for comparison with in situ data, size and shape parameters must be clearly defined. Digital image analysis is an adequate tool for providing objective (independent of operator) measurements of the snow characteristics. New methods are developed and applied to a large number of data from Antarctica mainly. Another field of research is the study of the ice core gaz content to get the past atmospheric composition. The snow mantle near the surface is porous and therefore there is a difference between the ages of the gaz and of the ice. Snow densification and diffusion models are then used to quantify those processes. The analysis of 2D digital images of Antarctic firn and ice at different depths provided the necessary parameters to validate the models. A third application of digital image analysis was the study of the grain growth in the deep ice. This growth depends on the temperature and the age of the ice. Grain size measurements from thin ice samples are necessary to validate the models. So far those measurements were done manually. New automatic tools were developed which give new insights to this field of study.
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Submitted on : Thursday, November 8, 2012 - 2:55:24 PM
Last modification on : Tuesday, March 17, 2020 - 2:03:50 AM
Document(s) archivé(s) le : Saturday, December 17, 2016 - 8:54:50 AM

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  • HAL Id : tel-00749857, version 1

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Michel Gay. Caractérisation de la neige, du névé et de la glace par traitement d'images. Glaciologie. Université Joseph-Fourier - Grenoble I, 1999. Français. ⟨tel-00749857⟩

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