Modeling of the L-Band emission and scattering of soil layers with consideration of Moisture and Temperature gradients.

• Main Authors: Demontoux, François, Lawrence, Heather, Wigneron, Jean Pierre, Mironov, V., Kosolapova, L.G., Kerr, Yann H.
• Other Authors: Laboratoire de l'intégration, du matériau au système (IMS), Université Sciences et Technologies - Bordeaux 1 (UB)-Institut Polytechnique de Bordeaux-Centre National de la Recherche Scientifique (CNRS), Centre d'études spatiales de la biosphère (CESBIO), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales Toulouse (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales Toulouse (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), Écologie fonctionnelle et physique de l'environnement (EPHYSE), Institut National de la Recherche Agronomique (INRA), Kirensky Institute of Physics, Russian Academy of Sciences Moscow (RAS), SMOS
• Format: Conference Object
• Language: English
• Published: HAL CCSD 2012
• Subjects: permittivity; modeling; temperature gradient; moisture gradient; remote sensing; SMOS; [SPI.ELEC]Engineering Sciences [physics]/Electromagnetism; [SDU.ENVI]Sciences of the Universe [physics]/Continental interfaces; environment; [SDU.STU.GP]Sciences of the Universe [physics]/Earth Sciences/Geophysics [physics.geo-ph]; [PHYS.PHYS.PHYS-GEO-PH]Physics [physics]/Physics [physics]/Geophysics [physics.geo-ph]; [SDE.MCG]Environmental Sciences/Global Changes; permafrost
• Online Access: https://hal.science/hal-00985951

International audience In the context of the European Space Agency's (ESA) Soil Moisture and Ocean Salinity (SMOS) mission, we present a study of the emission and of the bistatic scattering coefficient of rough surfaces at 1.4 GHz and the effects of moisture and temperature gradients. A new approach for the calculation of rough surface scattering and emission at L-band has recently been. This approach relies on the use of ANSYS's numerical computation software HFSS (High Frequency Structure Simulator), which in turn solves Maxwell's equations using the Finite Element Method (FEM). The interest of this approach is that it can be extended to calculate the emission and scattering of complicated multilayer media, including features such as volume effects, gradients effects and inclusions, as well as rough surfaces. At L band, volume effects in the upper layer of soil should be taken into account. In particular, moisture or thermal phenomena lead to the presence of gradients. In this paper we present the work we have done to use FEM method to compute thermal effects and water infiltration effects in ground. Coupling electromagnetic and thermal computation we are able to study scattering of media such as permafrost or effects of rapid changes in temperature condition. We can also study the effect of moisture gradients or the impact of rainfall events on bistatic scattering coefficient or emissivity of soil. It can also be very useful for global observations with a frequent repeat coverage (future NASA Soil Moisture Active/Passive mission SMAP). In the present study we present the effects of water infiltration in ground (as moisture gradients) on the emissivity and bi-static scattering coefficient of soil.