Now showing items 1-20 of 112

    • A general electromagnetic simulation tool to predict the microwave nonlinear response of planar, arbitrarily-shaped HTS structures 

      Parrón Granados, Josep; Collado Gómez, Juan Carlos; Mateu Mateu, Jordi; Rius Casals, Juan Manuel; Duffo Ubeda, Núria; O'Callaghan Castellà, Juan Manuel (IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC, 2001-03-31)
      Article
      Open Access
      This work describes a simulation tool being developed at UPC to predict the microwave nonlinear behavior of planar superconducting structures with very few restrictions on the geometry of the planar layout. The software ...
    • A new space technology for ocean observation: the SMOS mission 

      Font Ferré, Jordi; Ballabrera Poy, Joaquim; Camps Carmona, Adriano José; Corbella Sanahuja, Ignasi; Duffo Ubeda, Núria; Durán Martínez, Israel; Emelianov Kolomitski, Mikhail; Enrique González, Luis; Fernández Gallego, Pedro; Gabarró Prats, Carolina; González, Cristina; González, Veronica; Gourrion, J.; Guimbard, S.; Hoareau, N.; Julià, A; Kalaroni, S.; Konstantinidou, Anna; Aretxabaleta, L.; Martínez, Justino; Miranda, Jorge Miguel; Monerris Belda, Alessandra; Montero, Sergio; Mourre, B.; Pablos Hernández, Miriam; Pérez Villar, Fernando; Piles Guillem, Maria; Portabella, M.; Sabia, R.; Salvador, Joaquin; Talone, Marco; Torres Torres, Francisco; Turiel Martínez, Antonio; Vall-Llossera Ferran, Mercedes Magdalena; Villarino Villarino, Ramón (2012)
      Article
      Restricted access - publisher's policy
      Capability for sea surface salinity observation was an important gap in ocean remote sensing in the last few decades of the 20th century. New technological developments during the 1990s at the European Space Agency led to ...
    • Analysis of Correlation and Total Power Radiometer Front-Ends Using Noise Waves 

      Corbella Sanahuja, Ignasi; Torres Torres, Francisco; Camps Carmona, Adriano José; Duffo Ubeda, Núria; Vall-Llossera Ferran, Mercedes Magdalena; Rautiainen, Kimmo; Martín Neira, Manuel; Colliander, Andreas (IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC, 2005-11-30)
      Article
      Open Access
      A complete and systematic noise analysis of radiometer front-ends, including both total power and correlation measurements, is presented. The procedure uses the concepts of noise waves and S-parameters, widely used in ...
    • Analysis of correlation and total power radiometer front-ends using noise waves 

      Corbella Sanahuja, Ignasi; Torres Torres, Francisco; Camps Carmona, Adriano José; Duffo Ubeda, Núria; Vall-Llossera Ferran, Mercedes Magdalena; Rautiainen, Kimmo; Martín Neira, Manuel; Colliander, Andreas (IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC, 2005-11-30)
      Article
      Open Access
      A complete and systematic noise analysis of radiometer front-ends, including both total power and correlation measurements, is presented. The procedure uses the concepts of noise waves and S-parameters, widely used in ...
    • Application of the boundary elements method to 3-d radiation problem 

      Abad, J.; Duffo Ubeda, Núria; Rius Casals, Juan Manuel; Cruellas Ibarz, Juan Carlos (. REED EXHIBITION COMPANIES, 1993)
      Conference report
      Open Access
      In order to analyze the electromagnetic fields generated by perfectly conducting bodies composed by interconnected wires and solid objects, whichever its geometry, the Boundary Element Method is applied. The basic formulation ...
    • Assessment on linearity errors in detectors for interferometric radiometers 

      Torres Torres, Francisco; Duffo Ubeda, Núria; Gonzalez-Haro, Cristina; Vilaseca, R; Sagués, L; Martín-Neira, Manuel (2008)
      Conference report
      Restricted access - publisher's policy
      The performance of the power detectors used to denormalize the digital correlations in interferometric radiometers is degraded due to the non-linear behavior of the diode response. This work presents a comprehensive ...
    • Boundary element method applied to polarimetric radiometry of rain events 

      Duffo Ubeda, Núria; Vall-Llossera Ferran, Mercedes Magdalena; Camps Carmona, Adriano José; Corbella Sanahuja, Ignasi; Bará Temes, Francisco Javier; Torres Torres, Francisco (Institute of Electrical and Electronics Engineers (IEEE), 2000)
      Conference report
      Open Access
    • Brightness-temperature retrival methods in synthetic aperture radiometers 

      Corbella Sanahuja, Ignasi; Torres Torres, Francisco; Camps Carmona, Adriano José; Duffo Ubeda, Núria; Vall-Llossera Ferran, Mercedes Magdalena (IEEE, 2009-01)
      Article
      Open Access
      Bightness-temperature retrieval techniques for synthetic aperture radiometers are reviewed. Three different approaches to combine measured visibility and antenna temperatures, along with instrument characterization ...
    • Calibratin of fully polarimetric radiometers: the LAURA radiometer 

      Camps Carmona, Adriano José; Corbella Sanahuja, Ignasi; Duffo Ubeda, Núria; Vall-Llossera Ferran, Mercedes Magdalena; Torres Torres, Francisco; Bará Temes, Francisco Javier (2000)
      Conference report
      Open Access
    • Calibration consistency tool for interferometric radiometers 

      González-Gambau, Verónica; Torres Torres, Francisco; Duffo Ubeda, Núria; Martín-Neira, Manuel (2008)
      Conference report
      Restricted access - publisher's policy
      This paper presents a method to check the consistency of the amplitude calibration in interferometric radiometers devoted to Earth observation This tool is based in the intrinsic properties of the internal calibration ...
    • Calibration methods in large interferometric radiometers devoted to earth observation 

      Torres Torres, Francisco; Camps Carmona, Adriano José; Corbella Sanahuja, Ignasi; Bará Temes, Francisco Javier; Duffo Ubeda, Núria; Vall-Llossera Ferran, Mercedes Magdalena (VSP, 2000-01)
      Part of book or chapter of book
      Restricted access - publisher's policy
      This paper starts with a summary and classification of errors of any kind that corrupt the fundamental measurement performed by an InR (interferometric radiometer), the so-called visibilities. This summary is based on prior ...
    • Calibration of the MIRAS Radiometers 

      Corbella Sanahuja, Ignasi; Torres Torres, Francisco; Duffo Ubeda, Núria; Durán Martínez, Israel; González Gambau, Verónica; Oliva Balagué, Roger; Closa, Josep; Martín Neira, Manuel (Institute of Electrical and Electronics Engineers (IEEE), 2018-12-21)
      Article
      Open Access
      The microwave imaging radiometer with aperture synthesis (MIRAS) is formed by 69 total power radiometers, of which three are the noise-injection type. Their calibration is reviewed on the basis of the data gathered during ...
    • Calibration procedures in 2-D large interferometric radiometers study applied to the MIRAS/SMOS instrument 

      Torres Torres, Francisco; Camps Carmona, Adriano José; Corbella Sanahuja, Ignasi; Bará Temes, Francisco Javier; Vall-Llossera Ferran, Mercedes Magdalena; Duffo Ubeda, Núria (2000)
      Conference report
      Open Access
    • Calibration trade-off in large interferometric radiometers devoted to earth observation 

      Torres Torres, Francisco; Camps Carmona, Adriano José; Corbella Sanahuja, Ignasi; Bará Temes, Francisco Javier; Duffo Ubeda, Núria; Vall-Llossera Ferran, Mercedes Magdalena (Centro Stampa, 1999)
      Conference report
      Open Access
    • Cálculo de la radiación en 3D mediante el método de los elementos de contorno 

      Abad, J.; Duffo Ubeda, Núria; Rius Casals, Juan Manuel; Cardama Aznar, Ángel (Universidad de Málaga, 1992)
      Conference report
      Open Access
    • Cálculo de radiación en 3 dimensiones mediante el método de los elementos de contorno 

      Duffo Ubeda, Núria; Rius Casals, Juan Manuel; Cardama Aznar, Ángel (1992)
      Conference report
      Open Access
      In order to analize the electromagnetic fields generated by perfectly conducting bodies whichever it is its geometry, the Boundary Element Method is applied. The basic formulation and associated items (integral equations ...
    • Considerations About Antenna Pattern Measurements of 2-D Aperture Synthesis Radiometers 

      Camps Carmona, Adriano José; Skou, Neils; Torres Torres, Francisco; Corbella Sanahuja, Ignasi; Duffo Ubeda, Núria (IEEE, 2006-04-30)
      Article
      Open Access
      Accurate measurement of the antenna voltage patterns of large-aperture synthesis radiometers is critical in order to achieve good radiometric accuracy, and a very time consuming and expensive task. Measurement requirements ...
    • Considerations about antenna pattern measurements of 2-D aperture synthesis radiometers 

      Camps Carmona, Adriano José; Skou, Neils; Torres Torres, Francisco; Corbella Sanahuja, Ignasi; Duffo Ubeda, Núria (IEEE, 2006-04-30)
      Article
      Open Access
      Accurate measurement of the antenna voltage patterns of large-aperture synthesis radiometers is critical in order to achieve good radiometric accuracy, and a very time consuming and expensive task. Measurement requirements ...
    • Correction of spatial errors in SMOS brightness temperature images 

      Wu, Lin; Corbella Sanahuja, Ignasi; Torres Torres, Francisco; Duffo Ubeda, Núria; Martín-Neira, Manuel (IEEE, 2011)
      Conference report
      Restricted access - publisher's policy
      Systematic spatial errors in SMOS brightness temperature images are successfully estimated by using a statistical analysis of measured data. A constant multiplicative mask is derived by averaging spatial errors of a large ...
    • Denormalization of visibilities for in-orbit calibration of interferometric radiometers 

      Torres Torres, Francisco; Corbella Sanahuja, Ignasi; Camps Carmona, Adriano José; Duffo Ubeda, Núria; Vall-Llossera Ferran, Mercedes Magdalena; Beraza Robledano, Santiago; Gutiérrez, C.; Martín Neira, Manuel (IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC, 2006-10-31)
      Article
      Open Access
      This paper reviews the relative calibration of an interferometric radiometer taking into account the experimental results of the first batch of receivers developed in the frame of the European Space Agency's Soil Moisture ...