SMOS and aquarius radiometers: inter-comparison over selected targets
Passive microwave remote sensing at L-band is considered to be the most suitable technique to measure soil moisture and ocean salinity. These two variables are needed as inputs of predictive models, to improve climate and weather forecast, and to increase our knowledge of the water cycle. Nowadays,...
Published in: | IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing |
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Online Access: | http://hdl.handle.net/2117/25154 https://doi.org/10.1109/JSTARS.2014.2321455 |
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ftupcatalunya:oai:upcommons.upc.edu:2117/25154 2023-05-15T13:50:24+02:00 SMOS and aquarius radiometers: inter-comparison over selected targets Pablos Hernández, Miriam Piles Guillem, Maria González Gambau, Veronica Vall-Llossera Ferran, Mercedes Magdalena Camps Carmona, Adriano José Martinez, Justino Universitat Politècnica de Catalunya. Departament de Teoria del Senyal i Comunicacions Universitat Politècnica de Catalunya. CTE-CRAE - Grup de Recerca en Ciències i Tecnologies de l'Espai Universitat Politècnica de Catalunya. RSLAB - Grup de Recerca en Teledetecció 2014-09-01 12 p. http://hdl.handle.net/2117/25154 https://doi.org/10.1109/JSTARS.2014.2321455 eng eng Restricted access - publisher's policy Àrees temàtiques de la UPC::Enginyeria de la telecomunicació::Radiocomunicació i exploració electromagnètica::Teledetecció Àrees temàtiques de la UPC::Enginyeria civil::Geologia::Oceanografia Soil moisture--Measurement Remote sensing Aquarius/Satelite de Aplicaciones Cientificas (SAC)-D mission Brightness temperature Inter-comparison L-band radiometer Passive microwave remote sensing Soil Moisture and Ocean Salinity (SMOS) mission Antarctica Calibration Instrument Resolution Salinity Surface Teledetecció Sòls -- Humitat -- Mesurament Article 2014 ftupcatalunya https://doi.org/10.1109/JSTARS.2014.2321455 2019-09-29T08:55:24Z Passive microwave remote sensing at L-band is considered to be the most suitable technique to measure soil moisture and ocean salinity. These two variables are needed as inputs of predictive models, to improve climate and weather forecast, and to increase our knowledge of the water cycle. Nowadays, there are two space missions providing frequent and global observations of moisture and salinity of the Earth's surface with L-band radiometers on-board. The first one is the ESA's SMOS satellite, launched on November 2, 2009, which carries a two-dimensional, multi-angular, and full-polarimetric synthetic aperture radiometer. The second one is the NASA/CONAE's Aquarius/SAC-D mission, launched on June 10, 2011, which includes three beam push-broom real aperture radiometers. The objective of this work is to compare SMOS and Aquarius brightness temperatures and verify the continuity and consistency of the data over the entire dynamic range of observations. This is paramount if data from both radiometers are used for any long term enviromental, meteorological, hydrological, or climatological studies. The inter-comparison approach proposed is based on the study of 1 year of measurements over key target regions selected as representative of land, ice, and sea surfaces. The level of linearity, the correlation, and the differences between the observations of the two radiometers are analyzed. Results show a higher linear correlation between SMOS and Aquarius brightness temperatures over land than over sea. A seasonal effect and spatial inhomogeneities are observed over ice, at the Dome-C region. In all targets, better agreement is found in horizontal than in vertical polarization. Also, the correlation is higher at higher incidence angles. These differences indicate that there is a non-linear effect between the two instruments, not only a bias. Peer Reviewed Postprint (published version) Article in Journal/Newspaper Antarc* Antarctica Universitat Politècnica de Catalunya (UPC): Theses and Dissertations Online (TDX) IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing 7 9 3833 3844 |
institution |
Open Polar |
collection |
Universitat Politècnica de Catalunya (UPC): Theses and Dissertations Online (TDX) |
op_collection_id |
ftupcatalunya |
language |
English |
topic |
Àrees temàtiques de la UPC::Enginyeria de la telecomunicació::Radiocomunicació i exploració electromagnètica::Teledetecció Àrees temàtiques de la UPC::Enginyeria civil::Geologia::Oceanografia Soil moisture--Measurement Remote sensing Aquarius/Satelite de Aplicaciones Cientificas (SAC)-D mission Brightness temperature Inter-comparison L-band radiometer Passive microwave remote sensing Soil Moisture and Ocean Salinity (SMOS) mission Antarctica Calibration Instrument Resolution Salinity Surface Teledetecció Sòls -- Humitat -- Mesurament |
spellingShingle |
Àrees temàtiques de la UPC::Enginyeria de la telecomunicació::Radiocomunicació i exploració electromagnètica::Teledetecció Àrees temàtiques de la UPC::Enginyeria civil::Geologia::Oceanografia Soil moisture--Measurement Remote sensing Aquarius/Satelite de Aplicaciones Cientificas (SAC)-D mission Brightness temperature Inter-comparison L-band radiometer Passive microwave remote sensing Soil Moisture and Ocean Salinity (SMOS) mission Antarctica Calibration Instrument Resolution Salinity Surface Teledetecció Sòls -- Humitat -- Mesurament Pablos Hernández, Miriam Piles Guillem, Maria González Gambau, Veronica Vall-Llossera Ferran, Mercedes Magdalena Camps Carmona, Adriano José Martinez, Justino SMOS and aquarius radiometers: inter-comparison over selected targets |
topic_facet |
Àrees temàtiques de la UPC::Enginyeria de la telecomunicació::Radiocomunicació i exploració electromagnètica::Teledetecció Àrees temàtiques de la UPC::Enginyeria civil::Geologia::Oceanografia Soil moisture--Measurement Remote sensing Aquarius/Satelite de Aplicaciones Cientificas (SAC)-D mission Brightness temperature Inter-comparison L-band radiometer Passive microwave remote sensing Soil Moisture and Ocean Salinity (SMOS) mission Antarctica Calibration Instrument Resolution Salinity Surface Teledetecció Sòls -- Humitat -- Mesurament |
description |
Passive microwave remote sensing at L-band is considered to be the most suitable technique to measure soil moisture and ocean salinity. These two variables are needed as inputs of predictive models, to improve climate and weather forecast, and to increase our knowledge of the water cycle. Nowadays, there are two space missions providing frequent and global observations of moisture and salinity of the Earth's surface with L-band radiometers on-board. The first one is the ESA's SMOS satellite, launched on November 2, 2009, which carries a two-dimensional, multi-angular, and full-polarimetric synthetic aperture radiometer. The second one is the NASA/CONAE's Aquarius/SAC-D mission, launched on June 10, 2011, which includes three beam push-broom real aperture radiometers. The objective of this work is to compare SMOS and Aquarius brightness temperatures and verify the continuity and consistency of the data over the entire dynamic range of observations. This is paramount if data from both radiometers are used for any long term enviromental, meteorological, hydrological, or climatological studies. The inter-comparison approach proposed is based on the study of 1 year of measurements over key target regions selected as representative of land, ice, and sea surfaces. The level of linearity, the correlation, and the differences between the observations of the two radiometers are analyzed. Results show a higher linear correlation between SMOS and Aquarius brightness temperatures over land than over sea. A seasonal effect and spatial inhomogeneities are observed over ice, at the Dome-C region. In all targets, better agreement is found in horizontal than in vertical polarization. Also, the correlation is higher at higher incidence angles. These differences indicate that there is a non-linear effect between the two instruments, not only a bias. Peer Reviewed Postprint (published version) |
author2 |
Universitat Politècnica de Catalunya. Departament de Teoria del Senyal i Comunicacions Universitat Politècnica de Catalunya. CTE-CRAE - Grup de Recerca en Ciències i Tecnologies de l'Espai Universitat Politècnica de Catalunya. RSLAB - Grup de Recerca en Teledetecció |
format |
Article in Journal/Newspaper |
author |
Pablos Hernández, Miriam Piles Guillem, Maria González Gambau, Veronica Vall-Llossera Ferran, Mercedes Magdalena Camps Carmona, Adriano José Martinez, Justino |
author_facet |
Pablos Hernández, Miriam Piles Guillem, Maria González Gambau, Veronica Vall-Llossera Ferran, Mercedes Magdalena Camps Carmona, Adriano José Martinez, Justino |
author_sort |
Pablos Hernández, Miriam |
title |
SMOS and aquarius radiometers: inter-comparison over selected targets |
title_short |
SMOS and aquarius radiometers: inter-comparison over selected targets |
title_full |
SMOS and aquarius radiometers: inter-comparison over selected targets |
title_fullStr |
SMOS and aquarius radiometers: inter-comparison over selected targets |
title_full_unstemmed |
SMOS and aquarius radiometers: inter-comparison over selected targets |
title_sort |
smos and aquarius radiometers: inter-comparison over selected targets |
publishDate |
2014 |
url |
http://hdl.handle.net/2117/25154 https://doi.org/10.1109/JSTARS.2014.2321455 |
genre |
Antarc* Antarctica |
genre_facet |
Antarc* Antarctica |
op_rights |
Restricted access - publisher's policy |
op_doi |
https://doi.org/10.1109/JSTARS.2014.2321455 |
container_title |
IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing |
container_volume |
7 |
container_issue |
9 |
container_start_page |
3833 |
op_container_end_page |
3844 |
_version_ |
1766253463443865600 |