Enviaments recents

  • Temporal and spatial variations of global ionospheric total electron content under various solar conditions 

    Liu, Jingbin; Hernández Pajares, Manuel; Liang, Xinlian; An, Jiachun; Wang, Zemin; Chen, Ruizhi; Sun, Wei; Hyyppä, Juha (2016-12-09)
    Article
    Accés restringit per política de l'editorial
    By utilizing the numerical technique of principal component analysis (PCA), this work analyses temporal and spatial variations of the ionosphere under various solar conditions during the period 1999–2013. Applying the PCA ...
  • MONITOR Ionospheric Network: two case studies on scintillation and electron content variability 

    Beniguel, Yannick; Cherniak, Iurii; García Rigo, Alberto; Hamel, P.; Hernández Pajares, Manuel; Kameni, Roland; Kashcheyev, Anton; Krankowski, Andrzej; Monnerat, Michel; Nava, Bruno; Ngaya, Herbert; Orús Pérez, Raul; Secretan, Hugues; Serant, Damien; Schlüter, Stefan; Wilken, Volken (2017-03-13)
    Article
    Accés obert
    The ESA MONITOR network is composed of high-frequency-sampling global navigation satellite systems (GNSS) receivers deployed mainly at low and high latitudes to study ionosphere variability and jointly with global GNSS ...
  • Ionospheric tomography by gradient-enhanced kriging with STEC measurements and ionosonde characteristics 

    Minkwitz, David; van den Boogaart, K. Gerald; Gerzen, Tatjana; Hoque, Mainul; Hernández Pajares, Manuel (2016-11-14)
    Article
    Accés obert
    The estimation of the ionospheric electron density by kriging is based on the optimization of a parametric measurement covariance model. First, the extension of kriging with slant total electron content (STEC) measurements ...
  • The self organizing map of neighbour stars and its kinematical interpretation 

    Hernández Pajares, Manuel; Cubarsí Morera, Rafael; Monte Moreno, Enrique (1993-02)
    Article
    Accés obert
    The Self-Organizing Map (SOM) is a neural network algorithm that has the special property ofcreating spatially organized tepresetüatioes of various features of input signals. The resulting maps resemble realneural structures ...
  • Prediction and warning system of SEP events and solar flares for risk estimation in space launch operations 

    García Rigo, Alberto; Nuñez, Marlon; Qahwaji, Rami; Ashamari, Omar W; Jiggens, Piers; Pérez Querol, Gustau; Hernández Pajares, Manuel; Hilgers, Alain (2016-07-08)
    Article
    Accés obert
    A web-based prototype system for predicting solar energetic particle (SEP) events and solar flares for use by space launch operators is presented. The system has been developed as a result of the European Space Agency (ESA) ...
  • GPS as a solar observational instrument: real-time estimation of EUV photons flux rate during strong, medium, and weak solar flares 

    Singh, Talwinder; Hernández Pajares, Manuel; Monte Moreno, Enrique; García Rigo, Alberto; Olivares Pulido, Germán (2015-12-15)
    Article
    Accés obert
    In this manuscript, the authors show how the Global Navigation Satellite Systems, GNSS (exemplified in the Global Positioning System, GPS), can be efficiently used for a very different purpose from that for which it was ...
  • Long-term comparison of the ionospheric F2 layer electron density peak derived from ionosonde data and Formosat-3/COSMIC occultations 

    Limberger, Marco; Hernández Pajares, Manuel; Aragón Àngel, Angela; Altadill, David; Dettmering, Denise (2015-06-15)
    Article
    Accés obert
    Electron density profiles (EDPs) derived from GNSS radio occultation (RO) measurements provide valuable information on the vertical electron density structure of the ionosphere and, among others, allow the extraction of ...
  • North-south components of the annual asymmetry in the ionosphere 

    Gulyaeva, Tamara L.; Arikan, Feza; Hernández Pajares, Manuel; Veselovsky, I.S. (2014-07-01)
    Article
    Accés obert
    A retrospective study of the asymmetry in the ionosphere during the solstices is made using the different geospace parameters in the North and South magnetic hemispheres. Data of total electron content (TEC) and global ...
  • Distribution and mitigation of higher-order ionospheric effects on precise GNSS processing 

    Hernández Pajares, Manuel; Aragón Ángel, María Ángeles; Defraigne, Pascale; Bergeot, Nicolas; Prieto Cerdeira, Roberto; García Rigo, Alberto (2014-04)
    Article
    Accés obert
    Higher-order ionospheric effects (I2+) are one of the main limiting factors in very precise Global Navigation Satellite Systems (GNSS) processing, for applications where millimeter accuracy is demanded. This paper summarizes ...
  • GIM-TEC adaptive ionospheric weather assessment and forecast system 

    Gulyaeva, Tamara L.; Arikan, Feza; Hernández Pajares, Manuel; Stanislawska, Iwona (2013-09)
    Article
    Accés obert
    The Ionospheric Weather Assessment and Forecast (IWAF) system is a computer software package designed to assess and predict the world-wide representation of 3-D electron density profiles from the Global Ionospheric Maps ...

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