Global surface effects estimated by the L-band SMOS satellite
The Soil Moisture and Ocean Salinity (SMOS) mission is the first satellite dedicated to providing global surface soil moisture (SM). SMOS operates at L-band (1.4 GHz) and at this frequency, the signal depends on soil moisture and vegetation optical depth but it is also significantly affected by surf...
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HAL CCSD
2016
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Online Access: | https://hal.science/hal-01595153 |
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ftutoulouse3hal:oai:HAL:hal-01595153v1 |
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record_format |
openpolar |
institution |
Open Polar |
collection |
Université Toulouse III - Paul Sabatier: HAL-UPS |
op_collection_id |
ftutoulouse3hal |
language |
English |
topic |
soil moisture and ocean salinity remote sensing data analysis capteur smos télédétection donnée satellite analyse de données rugosité du sol [SPI.SIGNAL]Engineering Sciences [physics]/Signal and Image processing [SDE.MCG]Environmental Sciences/Global Changes |
spellingShingle |
soil moisture and ocean salinity remote sensing data analysis capteur smos télédétection donnée satellite analyse de données rugosité du sol [SPI.SIGNAL]Engineering Sciences [physics]/Signal and Image processing [SDE.MCG]Environmental Sciences/Global Changes Parrens, Marie Mialon, Arnaud Wigneron, Jean-Pierre Fernandez Moran, Roberto Richaume, Philippe Ahmad, Al Bitar Kerr, Yann H. Global surface effects estimated by the L-band SMOS satellite |
topic_facet |
soil moisture and ocean salinity remote sensing data analysis capteur smos télédétection donnée satellite analyse de données rugosité du sol [SPI.SIGNAL]Engineering Sciences [physics]/Signal and Image processing [SDE.MCG]Environmental Sciences/Global Changes |
description |
The Soil Moisture and Ocean Salinity (SMOS) mission is the first satellite dedicated to providing global surface soil moisture (SM). SMOS operates at L-band (1.4 GHz) and at this frequency, the signal depends on soil moisture and vegetation optical depth but it is also significantly affected by surface effects and in particular by the soil roughness. However, when dense vegetation is present, the L-band signal is poorly sensitive to the soil effects. First, by using multiple regressions between soil moisture (SM) and brightness temperature (TB) at different incidence angles and polarizations, SMOS sensitivity to the soil effects are evaluated. A global-scale map of SMOS sensitivity to the soil effects is computed and shows that for 87\% of the land surfaces, the SMOS observations are sensitive to the soil effects, while a very low sensitivity to the soil effects was estimated over ~ 13% of the land surfaces. For instance, over broadleaf evergreen forest (essentially the Amazon and Congo forest), SMOS is sensitive to the soil effects for only half of the pixels considered. In a second step, in L-MEB (L-band Microwave Emission of the Biosphere), the forward emission model of the SMOS algorithm , the vegetation and roughness effects were combined in only one parameter referred to as TR in this study. By inverting L-MEB, SM and TR were retrieved at global scale from the SMOS Level 3 (L3) TB observations during 2011. Assuming a linear relationship between TR and LAI obtained by the MODIS data, the effects of roughness and vegetation were decoupled and a global map of soil roughness effects (Hr) was estimated. It was found that the spatial pattern of the Hr values can be associated to the main vegetation types. Higher values of roughness (Hr=0.37-0.41) were obtained for forests (broadleaf evergreen, deciduous and mixed coniferous) while the lower values (Hr=0.15-0.17) were obtained for deserts, shrubs and bare soil. Intermediate values (Hr=0.15-0.20) were obtained over grasslands, tundra and cultivations Over ... |
author2 |
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) Interactions Sol Plante Atmosphère (UMR ISPA) Institut National de la Recherche Agronomique (INRA)-Ecole Nationale Supérieure des Sciences Agronomiques de Bordeaux-Aquitaine (Bordeaux Sciences Agro) |
format |
Conference Object |
author |
Parrens, Marie Mialon, Arnaud Wigneron, Jean-Pierre Fernandez Moran, Roberto Richaume, Philippe Ahmad, Al Bitar Kerr, Yann H. |
author_facet |
Parrens, Marie Mialon, Arnaud Wigneron, Jean-Pierre Fernandez Moran, Roberto Richaume, Philippe Ahmad, Al Bitar Kerr, Yann H. |
author_sort |
Parrens, Marie |
title |
Global surface effects estimated by the L-band SMOS satellite |
title_short |
Global surface effects estimated by the L-band SMOS satellite |
title_full |
Global surface effects estimated by the L-band SMOS satellite |
title_fullStr |
Global surface effects estimated by the L-band SMOS satellite |
title_full_unstemmed |
Global surface effects estimated by the L-band SMOS satellite |
title_sort |
global surface effects estimated by the l-band smos satellite |
publisher |
HAL CCSD |
publishDate |
2016 |
url |
https://hal.science/hal-01595153 |
op_coverage |
Espoo, Finland |
genre |
Tundra |
genre_facet |
Tundra |
op_source |
MicroRad 2016 - 14. Specialist Meeting on Microwave Radiometry and Remote Sensing of the Environment https://hal.science/hal-01595153 MicroRad 2016 - 14. Specialist Meeting on Microwave Radiometry and Remote Sensing of the Environment, Apr 2016, Espoo, Finland. Aalto University, Aalto University Publication Series. Science + Technology, 4, pp.communication orale, 2016, Aalto University Publication Series. Science + Technology |
op_relation |
ISBN: 978-952-60-6744-5 (printed) - 978-952-60-6743-8 (pdf) hal-01595153 https://hal.science/hal-01595153 PRODINRA: 351390 |
_version_ |
1809947071911821312 |
spelling |
ftutoulouse3hal:oai:HAL:hal-01595153v1 2024-09-09T20:12:29+00:00 Global surface effects estimated by the L-band SMOS satellite Parrens, Marie Mialon, Arnaud Wigneron, Jean-Pierre Fernandez Moran, Roberto Richaume, Philippe Ahmad, Al Bitar Kerr, Yann H. 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) Interactions Sol Plante Atmosphère (UMR ISPA) Institut National de la Recherche Agronomique (INRA)-Ecole Nationale Supérieure des Sciences Agronomiques de Bordeaux-Aquitaine (Bordeaux Sciences Agro) Espoo, Finland 2016-04-11 https://hal.science/hal-01595153 en eng HAL CCSD Aalto University ISBN: 978-952-60-6744-5 (printed) - 978-952-60-6743-8 (pdf) hal-01595153 https://hal.science/hal-01595153 PRODINRA: 351390 MicroRad 2016 - 14. Specialist Meeting on Microwave Radiometry and Remote Sensing of the Environment https://hal.science/hal-01595153 MicroRad 2016 - 14. Specialist Meeting on Microwave Radiometry and Remote Sensing of the Environment, Apr 2016, Espoo, Finland. Aalto University, Aalto University Publication Series. Science + Technology, 4, pp.communication orale, 2016, Aalto University Publication Series. Science + Technology soil moisture and ocean salinity remote sensing data analysis capteur smos télédétection donnée satellite analyse de données rugosité du sol [SPI.SIGNAL]Engineering Sciences [physics]/Signal and Image processing [SDE.MCG]Environmental Sciences/Global Changes info:eu-repo/semantics/conferenceObject Conference poster 2016 ftutoulouse3hal 2024-06-25T00:22:00Z The Soil Moisture and Ocean Salinity (SMOS) mission is the first satellite dedicated to providing global surface soil moisture (SM). SMOS operates at L-band (1.4 GHz) and at this frequency, the signal depends on soil moisture and vegetation optical depth but it is also significantly affected by surface effects and in particular by the soil roughness. However, when dense vegetation is present, the L-band signal is poorly sensitive to the soil effects. First, by using multiple regressions between soil moisture (SM) and brightness temperature (TB) at different incidence angles and polarizations, SMOS sensitivity to the soil effects are evaluated. A global-scale map of SMOS sensitivity to the soil effects is computed and shows that for 87\% of the land surfaces, the SMOS observations are sensitive to the soil effects, while a very low sensitivity to the soil effects was estimated over ~ 13% of the land surfaces. For instance, over broadleaf evergreen forest (essentially the Amazon and Congo forest), SMOS is sensitive to the soil effects for only half of the pixels considered. In a second step, in L-MEB (L-band Microwave Emission of the Biosphere), the forward emission model of the SMOS algorithm , the vegetation and roughness effects were combined in only one parameter referred to as TR in this study. By inverting L-MEB, SM and TR were retrieved at global scale from the SMOS Level 3 (L3) TB observations during 2011. Assuming a linear relationship between TR and LAI obtained by the MODIS data, the effects of roughness and vegetation were decoupled and a global map of soil roughness effects (Hr) was estimated. It was found that the spatial pattern of the Hr values can be associated to the main vegetation types. Higher values of roughness (Hr=0.37-0.41) were obtained for forests (broadleaf evergreen, deciduous and mixed coniferous) while the lower values (Hr=0.15-0.17) were obtained for deserts, shrubs and bare soil. Intermediate values (Hr=0.15-0.20) were obtained over grasslands, tundra and cultivations Over ... Conference Object Tundra Université Toulouse III - Paul Sabatier: HAL-UPS |