Exploració per autor "Corbella Sanahuja, Ignasi"
Ara es mostren els items 87-106 de 216
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Ill conditioning loci in noise parameter determination
O'Callaghan Castellà, Juan Manuel; Alegret, A.; Pradell i Cara, Lluís; Corbella Sanahuja, Ignasi (IEE-INST ELEC ENG, 1996-08-01)
Article
Accés obertAn analysis of the problem of noise parameter determination is carried out. It is found that the mathematical problem is ill-posed if all the source reflection coefficients (Γs) used in the measurements fall onto a line, ... -
Ill conditioning loci in noise parameter determination
O'Callaghan Castellà, Juan Manuel; Alegret Ginesta, Alexandre; Pradell i Cara, Lluís; Corbella Sanahuja, Ignasi (IEE-INST ELEC ENG, 1996-08-01)
Article
Accés obertAn analysis of the problem of noise parameter determination is carried out. It is found that the mathematical problem is ill-posed if all the source reflection coefficients (Γs) used in the measurements fall onto a line, ... -
Impact of amplitude calibration errors on SMOS global images
Durán Martínez, Israel; Corbella Sanahuja, Ignasi; Torres Torres, Francisco; Duffo Ubeda, Núria; Oliva, Roger; Martín Neira, Manuel (Institute of Electrical and Electronics Engineers (IEEE), 2016)
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Accés restringit per política de l'editorialSome of the artifacts observed in SMOS brightness temperature images are originated in an inconsistency between correlation and antenna temperature calibration errors, which produces a multiplicative bias that scales with ... -
Impact of antenna errors on the radiometric accuracy of large aperture synthesis radiometers
Camps Carmona, Adriano José; Bará Temes, Francisco Javier; Torres Torres, Francisco; Corbella Sanahuja, Ignasi; Romeu Robert, Jordi (1997-04)
Article
Accés restringit per política de l'editorialA classification of system errors in aperture synthesis radiometry applied to Earth observation is presented. A general procedure to quantify the impact of antenna errors on the radiometric accuracy is developed and is ... -
Impact of antenna errors on the radiometric accuracy of large aperture synthesis radiometers. Study applied to MIRAS
Camps Carmona, Adriano José; Bará Temes, Francisco Javier; Torres Torres, Francisco; Corbella Sanahuja, Ignasi; Romeu Robert, Jordi (American Geophysical Union, 1997-04-30)
Article
Accés obertA classification of system errors in aperture synthesis radiometry applied to Earth obervation is presented. A general procedure to quantify th eimpact of antenna errors on the radiometric accuracy is developed and is then ... -
Impact of antenna tuning on SMOS correlation loss
Torres Torres, Francisco; Durán Martínez, Israel; Corbella Sanahuja, Ignasi; Duffo Ubeda, Núria; Closa, Josep; Oliva, Roger; Martín-Neira, Manuel (Institute of Electrical and Electronics Engineers (IEEE), 2016)
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Accés restringit per política de l'editorialThe Soil Moisture and Ocean Salinity (SMOS) mission by the European Space Agency (ESA) was launched in 2009 [1]. Since then, it has produced a continuous stream of valuable geophysical data over land, ice and ocean [2] ... -
Impact of correlator efficiency errors on SMOS land-sea contamination
Corbella Sanahuja, Ignasi; Durán Martínez, Israel; Wu, Lin; Torres Canals, Francesc; Duffo Ubeda, Núria; Khazaal, Ali; Martín Neira, Manuel (2015-09-01)
Article
Accés obertLand-sea contamination observed in Soil Moisture and Ocean Salinity (SMOS) brightness temperature images is found to have two main contributions: the floor error inherent of image reconstruction and a multiplicative error ... -
Impact of receiver errors on the radiometric resolution of large two-dimensional aperture synthesis radiometers
Torres Torres, Francisco; Camps Carmona, Adriano José; Bará Temes, Francisco Javier; Corbella Sanahuja, Ignasi (1997-04)
Article
Accés restringit per política de l'editorialThe specifications of the subsystems that compound a radiometer interferometer devoted to Earth observation are of main concern because they set the viability and final performance of such an instrument. The importance of ... -
Impact of the local oscillator calibration rate on the SMOS measurements and retrieved salinities
Gabarró Prats, Carolina; Gonzalez Gambau, Verónica; Corbella Sanahuja, Ignasi; Torres Torres, Francisco (Institute of Electrical and Electronics Engineers (IEEE), 2013-09-02)
Article
Accés restringit per política de l'editorialThe local oscillators (LOs) of the Soil Moisture and Ocean Salinity mission payload are used to shift the operating frequency of the 72 receivers to an optimal intermediate frequency needed for the signal processing. ... -
Improvement of the pull in range and acquisition time of a microwave PLL system by injection locking the V.C.O
Berenguer Sau, Jordi; Bara, Javier; Artal, Eduardo; Corbella Sanahuja, Ignasi (1987)
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Accés obertThe requirements of large pull-in range and short acquisition time in microwave and millimeter wave phase locked oscillators are of great importance since the free running VCO frequency may be sorne tens of MHz off the ... -
In-orbit validations of SMOS full polarimetric equations
Torres Torres, Francisco; Corbella Sanahuja, Ignasi; Wu, Lin; Duffo Ubeda, Núria; Delwart, Steven; Martín Neira, Manuel (Institute of Electrical and Electronics Engineers (IEEE), 2013)
Text en actes de congrés
Accés restringit per política de l'editorialThis paper analyzes the consistency of SMOS fully polarimetric measurement mode by comparing measured data over the ocean with the expected results. These last are based on an accurate ocean model provided by LOCEAN and ... -
Increasing stratification as observed by satellite sea surface salinity measurements
Olmedo Casal, Estrella; Turiel Martínez, Antonio; González Gambau, Verónica; González Haro, Cristina; García Espriu, Aina; Gabarró Prats, Carolina; Portabella, Marcos; Corbella Sanahuja, Ignasi; Martín Neira, Manuel; Arias Ballesteros, Manuel; Catany, Rafael; Sabia, Roberto; Olivia, Roger; Scipal, Klaus (Nature, 2022-12-01)
Article
Accés obertChanges in the Earth’s water cycle can be estimated by analyzing sea surface salinity. This variable refects the balance between precipitation and evaporation over the ocean, since the upper layers of the ocean are the ... -
Instantaneous model of a MESFET for use in linear and nonlinear circuit simulations
Corbella Sanahuja, Ignasi; Legido, J.M.; Naval, G. (IEEE Microwave Theory and Techniques Society, 1992-07)
Article
Accés obertA formal approach for nonlinear modeling of FETs is presented. The intrinsic transistor is described by current and charge generators, that are instantaneously dependent on the two internal voltages. The extrinsic parasitic ... -
Integration of MIRAS breadboard and future activities
Martín Neira, Manuel; Goutoule, J.M.; Knight, A.; Claude, J.; Bará Temes, Francisco Javier; Camps Carmona, Adriano José; Torres Torres, Francisco; Corbella Sanahuja, Ignasi; Lannes, A.; Anterrieu, E.; Laursen, B.; Skou, N. (1996)
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Accés obertThe European Space Agency (ESA) is conducting a feasibility study on MIRAS, a Microwave Imaging Radiometer using two dimensional aperture synthesis, for the mapping of soil moisture and ocean salinity from space. An aircraft ... -
Interferometric radiometry and its applications
Camps Carmona, Adriano José; Bará Temes, Francisco Javier; Corbella Sanahuja, Ignasi; Torres Torres, Francisco; Duffo Ubeda, Núria; Vall-Llossera Ferran, Mercedes Magdalena (1999)
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Interferometric radiometry measurement concept: The visibility equation
Corbella Sanahuja, Ignasi; Torres Torres, Francisco; Duffo Ubeda, Núria; Martín-Neira, Manuel (IEEE, 2011)
Text en actes de congrés
Accés restringit per política de l'editorialThe fundamental concept of interferometric aperture synthesis microwave radiometry for Earth observation is reviewed. The measurement principles and a discussion on the signal processing techniques for image reconstruction ... -
L-band aperture synthesis radiometry: hardware requirements and system performance
Corbella Sanahuja, Ignasi; Torres Torres, Francisco; Camps Carmona, Adriano José; Bará Temes, Francisco Javier; Duffo Ubeda, Núria; Vall-Llossera Ferran, Mercedes Magdalena (IEEE Piscataway, 2000)
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Accés obertAperture synthesis radiometry is becoming a feasible concept for imaging applications, especially at low microwave frequencies where it takes clear advantage of the absence of mechanical antenna motion. A 2D interferometric ... -
L-Band sea surface emissivity: preliminary results of the WISE-2000 campaign and its application to salinity retrieval in the SMOS mission
Camps Carmona, Adriano José; Corbella Sanahuja, Ignasi; Vall-Llossera Ferran, Mercedes Magdalena; Duffo Ubeda, Núria; Torres Torres, Francisco; Villarino Villarino, Ramón; Enrique, L; Julbé, F; Font Capafons, Josep; Julià, A; Gabarró, C; Etcheto, J; Boutin, J; Weill, A; Caselles Costa, Vicent; Rubio, E; Wursteisen, P (2003-06)
Article
Accés obertSoil moisture and ocean salinity at surface level can be measured by passive microwave remote sensing at L-band. To provide global coverage data of soil moisture and ocean salinity with three-day revisit time, the Earth ... -
L-Band Sea Surface Emissivity: Preliminary Results Of The WISE-2000 Campaign And Its Application To Salinity Retrieval In the SMOS Mission
Camps Carmona, Adriano José; Corbella Sanahuja, Ignasi; Vall-Llossera Ferran, Mercedes Magdalena; Duffo Ubeda, Núria; Torres Torres, Francisco; Villarino Villarino, Ramón; Enrique, L.; Julbé, F.; Font, Jordi; Julià, A.; Gabarró Prats, Carolina; Etcheto, Jacqueline; Boutin, Jacqueline; Weill, Alain; Caselles, Vicente; Rubio, Eva; Wursteisen, Patrick (2003-06-30)
Article
Accés obertSoil moisture and ocean salinity at surface level can be measured by passive microwave remote sensing at L-band. To provide global coverage data of soil moisture and ocean salinity with three-day revisit time, the Earth ... -
Latitudinal and seasonal SMOS amplitude calibration assessment
Gonzalez Gambau, Verónica; Corbella Sanahuja, Ignasi; Torres Torres, Francisco; Duffo Ubeda, Núria; Turiel, Antonio (Institute of Electrical and Electronics Engineers (IEEE), 2014)
Text en actes de congrés
Accés restringit per política de l'editorialThe consistency of MIRAS amplitude calibration along the mission is a key issue to ensure a stable and accurate long-term dataset of ESA's SMOS soil moisture and ocean salinity data. Recent studies have revealed latitudinal ...