Contribution to the characterization of interferometric radiometers devoted to Earth observation: application to the MIRAS/SMOS payload

The variability of soil moisture and ocean salinity controls the continuous exchange of water between the oceans, the atmosphere and the land. Therefore, the accurate and periodic measurements of these geophysical variables are paramount to improve the climate change prediction and extreme-event for...

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Detalhes bibliográficos
Autor: González Gambau, Verónica
Formato: tesis doctoral
Fecha de publicación:2012
País:España
Recursos:Universitat Politècnica de Catalunya (UPC)
Repositorio:UPCommons. Portal del coneixement obert de la UPC
Idioma:inglés
OAI Identifier:oai:upcommons.upc.edu:2117/94678
Acesso em linha:https://hdl.handle.net/2117/94678
https://dx.doi.org/10.5821/dissertation-2117-94678
Access Level:acceso abierto
Palavra-chave:Interferometria
Radiació -- Mesurament
Àrees temàtiques de la UPC::Enginyeria de la telecomunicació
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network_acronym_str ES
network_name_str España
repository_id_str
dc.title.none.fl_str_mv Contribution to the characterization of interferometric radiometers devoted to Earth observation: application to the MIRAS/SMOS payload
title Contribution to the characterization of interferometric radiometers devoted to Earth observation: application to the MIRAS/SMOS payload
spellingShingle Contribution to the characterization of interferometric radiometers devoted to Earth observation: application to the MIRAS/SMOS payload
González Gambau, Verónica
Interferometria
Radiació -- Mesurament
Àrees temàtiques de la UPC::Enginyeria de la telecomunicació
title_short Contribution to the characterization of interferometric radiometers devoted to Earth observation: application to the MIRAS/SMOS payload
title_full Contribution to the characterization of interferometric radiometers devoted to Earth observation: application to the MIRAS/SMOS payload
title_fullStr Contribution to the characterization of interferometric radiometers devoted to Earth observation: application to the MIRAS/SMOS payload
title_full_unstemmed Contribution to the characterization of interferometric radiometers devoted to Earth observation: application to the MIRAS/SMOS payload
title_sort Contribution to the characterization of interferometric radiometers devoted to Earth observation: application to the MIRAS/SMOS payload
dc.creator.none.fl_str_mv González Gambau, Verónica
author González Gambau, Verónica
author_facet González Gambau, Verónica
author_role author
dc.contributor.none.fl_str_mv Dufo Úbeda, Nuria
Torres Torres, Francisco
dc.subject.none.fl_str_mv Interferometria
Radiació -- Mesurament
Àrees temàtiques de la UPC::Enginyeria de la telecomunicació
topic Interferometria
Radiació -- Mesurament
Àrees temàtiques de la UPC::Enginyeria de la telecomunicació
description The variability of soil moisture and ocean salinity controls the continuous exchange of water between the oceans, the atmosphere and the land. Therefore, the accurate and periodic measurements of these geophysical variables are paramount to improve the climate change prediction and extreme-event forecasting. However, until very recently, global measurements of these parameters with a suitable spatial and temporal resolution have not been available. Real aperture radiometers have been frequently used for Earth observation applications. Nevertheless, for space-borne sensors at a low Earth orbit, the requirements on spatial resolution and coverage, at the operating frequencies (L-band), would require an unfeasibly large antenna. Conversely, synthetic aperture radiometry achieves high resolution using an array of small antennas, becoming a sound alternative to real aperture radiometry at low microwave frequencies. The ESA's SMOS (Soil Moisture and Ocean Salinity) mission, successfully launched on November 2009, is the first mission ever attempted to frequently and globally measure soil moisture over the continents and sea surface salinity over the oceans. The single payload of the mission, the MIRAS (Microwave Imaging Radiometer by Aperture Synthesis) instrument, is the first spaceborne L-band two dimensional synthetic aperture radiometer. This completely new type of instrument implies a technological challenge, for which the development of a detailed error model denition, dedicated calibration and image reconstruction algorithms have been needed. The calibration of MIRAS tackles all activities devoted to retrieve the SMOS scientic products from raw data measurements with the accuracy required by the scientic community. Characterization activities of the MIRAS instrument, mainly performed prior to the beginning of the in-orbit operation, have been required to develop and test the calibration activities. Within the framework of the SMOS mission, this Ph.D. Thesis is focused on the characterization of the interferometric radiometers devoted to Earth observation. The main contributions of this Thesis, which are directly related to the MIRAS payload performance assessment, are: (i) the denition of tests for the characterization campaigns, data processing methods and success criteria and (ii) the development of calibration algorithms and tools to fine-tune the instrument in order to fully achieve the system requirements and therefore the scientific requierements of the mission. Most of the work has been done in the framework of the MIRAS/SMOS Pre-Commissioning Phase activities and it has been completed in the framework of the Commissioning Phase preparatory work. Calibration tools and techniques developed for the MIRAS ground characterization have been adapted to fulfill in-orbit instrument characterization during the first months of the Commissioning Phase and contributed to the development and consolidation of the SMOS operational level-1 processing.
publishDate 2012
dc.date.none.fl_str_mv 2012
2012-09-05
2012
2012-12-18
dc.type.none.fl_str_mv doctoral thesis
http://purl.org/coar/resource_type/c_db06
VoR
http://purl.org/coar/version/c_970fb48d4fbd8a85
dc.type.openaire.fl_str_mv info:eu-repo/semantics/doctoralThesis
format doctoralThesis
dc.identifier.none.fl_str_mv https://hdl.handle.net/2117/94678
https://dx.doi.org/10.5821/dissertation-2117-94678
url https://hdl.handle.net/2117/94678
https://dx.doi.org/10.5821/dissertation-2117-94678
dc.language.none.fl_str_mv Inglés
eng
language_invalid_str_mv Inglés
language eng
dc.rights.none.fl_str_mv open access
http://purl.org/coar/access_right/c_abf2

http://creativecommons.org/licenses/by-nc-nd/3.0/es/
dc.rights.openaire.fl_str_mv info:eu-repo/semantics/openAccess
rights_invalid_str_mv open access
http://purl.org/coar/access_right/c_abf2

http://creativecommons.org/licenses/by-nc-nd/3.0/es/
eu_rights_str_mv openAccess
dc.format.none.fl_str_mv application/pdf
dc.publisher.none.fl_str_mv Universitat Politècnica de Catalunya
publisher.none.fl_str_mv Universitat Politècnica de Catalunya
dc.source.none.fl_str_mv reponame:UPCommons. Portal del coneixement obert de la UPC
instname:Universitat Politècnica de Catalunya (UPC)
instname_str Universitat Politècnica de Catalunya (UPC)
reponame_str UPCommons. Portal del coneixement obert de la UPC
collection UPCommons. Portal del coneixement obert de la UPC
repository.name.fl_str_mv
repository.mail.fl_str_mv
_version_ 1869413427908182016
spelling Contribution to the characterization of interferometric radiometers devoted to Earth observation: application to the MIRAS/SMOS payloadGonzález Gambau, VerónicaInterferometriaRadiació -- MesuramentÀrees temàtiques de la UPC::Enginyeria de la telecomunicacióThe variability of soil moisture and ocean salinity controls the continuous exchange of water between the oceans, the atmosphere and the land. Therefore, the accurate and periodic measurements of these geophysical variables are paramount to improve the climate change prediction and extreme-event forecasting. However, until very recently, global measurements of these parameters with a suitable spatial and temporal resolution have not been available. Real aperture radiometers have been frequently used for Earth observation applications. Nevertheless, for space-borne sensors at a low Earth orbit, the requirements on spatial resolution and coverage, at the operating frequencies (L-band), would require an unfeasibly large antenna. Conversely, synthetic aperture radiometry achieves high resolution using an array of small antennas, becoming a sound alternative to real aperture radiometry at low microwave frequencies. The ESA's SMOS (Soil Moisture and Ocean Salinity) mission, successfully launched on November 2009, is the first mission ever attempted to frequently and globally measure soil moisture over the continents and sea surface salinity over the oceans. The single payload of the mission, the MIRAS (Microwave Imaging Radiometer by Aperture Synthesis) instrument, is the first spaceborne L-band two dimensional synthetic aperture radiometer. This completely new type of instrument implies a technological challenge, for which the development of a detailed error model denition, dedicated calibration and image reconstruction algorithms have been needed. The calibration of MIRAS tackles all activities devoted to retrieve the SMOS scientic products from raw data measurements with the accuracy required by the scientic community. Characterization activities of the MIRAS instrument, mainly performed prior to the beginning of the in-orbit operation, have been required to develop and test the calibration activities. Within the framework of the SMOS mission, this Ph.D. Thesis is focused on the characterization of the interferometric radiometers devoted to Earth observation. The main contributions of this Thesis, which are directly related to the MIRAS payload performance assessment, are: (i) the denition of tests for the characterization campaigns, data processing methods and success criteria and (ii) the development of calibration algorithms and tools to fine-tune the instrument in order to fully achieve the system requirements and therefore the scientific requierements of the mission. Most of the work has been done in the framework of the MIRAS/SMOS Pre-Commissioning Phase activities and it has been completed in the framework of the Commissioning Phase preparatory work. Calibration tools and techniques developed for the MIRAS ground characterization have been adapted to fulfill in-orbit instrument characterization during the first months of the Commissioning Phase and contributed to the development and consolidation of the SMOS operational level-1 processing.La variabilidad de la humedad del suelo y de la salinidad de los oc´eanos controla el continuo intercambio de agua entre los oc´eanos, la atm´osfera y la tierra. Por tanto, la obtenci´on de medidas precisas y peri´odicas de estas dos variables geof´ısicas es fundamental para la mejora de la predicci´on del cambio clim´atico y de la previsi´on de desastres naturales. Sin embargo, hasta hace muy poco no se dispon´ıa de medidas globales de estos par´ametros con la resoluci´on temporal y espacial necesaria para este tipo de aplicaciones. Los radi´ometros de apertura real se han utilizado frecuentemente para aplicaciones de observaci´on de la Tierra. Sin embargo, para sensores situados en ´orbitas bajas, los requerimientos de resoluci´on espacial y cobertura, a la frecuencia de trabajo (banda L), implicar´ıan el uso de una antena de unas dimensiones que no son viables tecnol´ogicamente. Por el contrario, la radiometr´ıa de apertura sint´etica permite obtener una alta resoluci´on utilizando un array de peque˜nas antenas, convirti´endose en una s´olida alternativa a la radiometr´ıa de apertura real para frecuencias bajas de microondas. La misi´on SMOS, de la Agencia Espacial Europea, lanzada con ´exito en Noviembre de 2009, es la primera misi´on para la medida frecuente y global de la humedad del suelo y la salinidad de los oc´eanos. La ´unica carga ´util de la misi´on, el instrumento MIRAS, es el primer radi´ometro de apertura sint´etica en dos dimensiones que es lanzado al espacio. Este tipo de instrumento, completamente novedoso, implica todo un reto tecnol´ogico, por lo que han sido necesarios la definici´on de un modelo detallado de errores y el desarrollo de algoritmos espec´ıficos de calibraci´on e inversi´on de imagen. La calibraci´on del radi´ometro MIRAS comprende todas las actividades dedicadas a recuperar los productos cient´ıficos de SMOS a partir de los datos crudos con la precisi´on requerida por la comunidad cient´ıfica. Para poder desarrollar y probar las actividades de calibraci´on ha sido preciso realizar campa˜nas de caracterizaci´on del instrumento, llevadas a cabo en tierra principalmente. En el marco de la misi´on SMOS, esta tesis se centra en la caracterizaci´on de radi´ometros interfer´ometricos para la observaci´on de la Tierra. Las principales contribuciones de esta tesis, relacionadas directamente con la evaluaci´on de las prestaciones del radi´ometro MIRAS, son: (i) la definici´on de las medidas para las campa˜nas de caracterizaci´on, m´etodos de procesado de datos y criterios de ´exito y (ii) el desarrollo de algoritmos de calibraci´on y herramientas que permitan el ajuste del intrumento para cumplir los requerimientos del sistema y por lo tanto, los requerimientos cient´ıficos de la misi´on. La mayor parte de este trabajo se ha realizado en el marco de las actividades previas al lanzamiento de la misi´on y se ha completado en el marco del trabajo preparatorio de la fase de comisionado (primeros meses de medidas en ´orbita). Las herramientas de calibraci´on y las t´ecnicas desarrolladas para la caracterizaci´on en tierra del instrumento se han adaptado para completar la caracterizaci´on del instrumento durante los primeros meses en ´orbita, contribuyendo al procesado de nivel 1 operacional.Universitat Politècnica de CatalunyaDufo Úbeda, NuriaTorres Torres, Francisco20122012-09-0520122012-12-18doctoral thesishttp://purl.org/coar/resource_type/c_db06VoRhttp://purl.org/coar/version/c_970fb48d4fbd8a85info:eu-repo/semantics/doctoralThesisapplication/pdfhttps://hdl.handle.net/2117/94678https://dx.doi.org/10.5821/dissertation-2117-94678reponame:UPCommons. Portal del coneixement obert de la UPCinstname:Universitat Politècnica de Catalunya (UPC)Inglésengopen accesshttp://purl.org/coar/access_right/c_abf2http://creativecommons.org/licenses/by-nc-nd/3.0/es/info:eu-repo/semantics/openAccessoai:upcommons.upc.edu:2117/946782026-05-27T15:37:01Z
score 15,301603

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