- Names
-
- A. Pommerol
- Title
- Hydratation minérale à la surface de mars : Caractérisation spectroscopique, thermodynamique et application a la télédétection
- Abstract
- The Solar light reflected by the Martian surface in the spectral range of near infrared reveals the signature of water present in hydrated minerals located in the regolith. Successive remote-sensing instruments on-board space probes caracterized the spatial and seasonal variabilities of these spectral signatures. However, the physical interpretation of spectroscopic signals is highly challenging in the case of reflexion spectroscopy. Many parameters concerning different aspects of the measurement are likely to influence the reflectance spectra. In the laboratory, we studied the effects of particules size, mixtures between different materials, incidence, emergence and phase angle on the strength of two absorption bands at 1.9 and 3 μm. Using simultaneously laboratory measurements and radiative transfer numerical modeling, we were able to derive quantitative relationships between those parameters. In the same time, we developed an original experimental facility designed to measure adsorption and desorption isotherms of Martian reglith analog materials under conditions representative of the Martian surface. Visible and near infrared reflectance spectra are also measured at each step of the hydration and dehydration processes. Results allow better understanding of the possible interactions between water and minerals and the spectrosopic properties of water-of-hydration. Finally, we show how results obtained in the laboratory apply to the case of the Martian surface thanks to the OMEGA / Mars Express dataset. The causes of spatial and seasonal variabilities of the surface spectral signatures are especially discussed.
- Keywords
- spectroscopy, thermodynamics, sample cell, spectro-gonio radiometer, bidirectional reflection, radiative transfer simulation, bidirectional reflectance spectra, BRDF, visible, near-IR, band position, band intensity, band integrated intensity, mechanical process, fluid process, adsorption, grain size, mineral, smectite Swy-2, smectite STx-1, palagonite JSC Mars-1, ferrihydrite, dunite, basaltic volcanic tuff, epsomite - magnesium sulfate, immature coal PSOC 1532, anthracite coal PSOC 1468, gypsum, H2O, Mars, surface, Mars Express - OMEGA, MGS - TES
- Content
- instrument-technique, sample, material-matter, spectral data, thermodynamic data, planetary sciences, earth sciences
- Document type
- phd thesis
- Year
- 2009
- Pages
- 1 - 254
- Pages number
- 254
- Editor
- LPG
- Publisher
- Université Joseph Fourier
- Publisher city
- Grenoble, France
- Publication state
- published
- Comments
- 13 January 2009
- Identifiers
- File
- pommerol09-PhD-UJF.pdf