Simulations of the altimetric signal intensity from 3D-layered air/snow/sea-ice rough interfaces

International audience Remote sensing of the sea-ice thickness is one of the main objectives of the Ku-band radar altimeter SIRAL-CRYOSAT II mission. On the one hand, sea-ice thickness is derived from the measurement of the height of the freeboard of the floes, and based on isostasy, assuming that t...

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Bibliographic Details
Published in:2014 XXXIth URSI General Assembly and Scientific Symposium (URSI GASS)
Main Authors: Dusséaux, Richard, Afifi, Saddek, Dechambre, Monique, Legresy, Benoit
Other Authors: ESTER - LATMOS, Laboratoire Atmosphères, Milieux, Observations Spatiales (LATMOS), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Physique des Lasers, de Spectroscopie Optique et d’Opto-électronique (LAPLASO), Université Badji Mokhtar Annaba (UBMA), Laboratoire d'études en Géophysique et océanographie spatiales (LEGOS), 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 de Recherche pour le Développement (IRD)-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)
Format: Conference Object
Language:English
Published: HAL CCSD 2014
Subjects:
Online Access:https://hal.science/hal-01077650
https://doi.org/10.1109/URSIGASS.2014.6929595
Description
Summary:International audience Remote sensing of the sea-ice thickness is one of the main objectives of the Ku-band radar altimeter SIRAL-CRYOSAT II mission. On the one hand, sea-ice thickness is derived from the measurement of the height of the freeboard of the floes, and based on isostasy, assuming that the density of the water, the ice, as well as the snow, are known. On the other hand even if the snow load is known, the penetration of the electromagnetic waves into the snow strongly depends on the electrical and geophysical characteristics of the snow layer (density, temperature, permittivity, roughness). The remote sensing of the snow layer thickness (SLT) remains a real challenge and will be useful to correct the snow load for converting freeboard measurements from satellite altimetry into sea-ice thickness. If the dual frequency radar altimetry data show a good potential for remote sensing of snow and more generally of penetrating media [1], providing the SLT from Ku band data alone is highly motivated by the orbit of CRYOSAT designed to cover the entire Arctic. In this framework, a theoretical study, based on a 3D modelling of the scattering of electromagnetic waves by a stratified medium at normal incidence has been carried out in order to investigate and quantify the capacity of snow and ice penetration of Ku-band waves. The stratified medium is modelled as a snow layer considered as a stack of 2 sub-layers and the boundary layer at the bottom represented by a semi-infinite layer of ice-sea as shown on the figure 1. The roughness of each interface is taken into account and the small slope approximation (SSA) is used to determine the coherent and incoherent components of the scattered intensity [2-4]. It is demonstrated that the coherent intensity is the the specular direction but it depends on the rms-roughness heights and does not depends on the shape of the correlation function. The incoherent intensity depends even on the rms-roughness heights, but also on the shape of the correlati- n function. Several ...