Near real-time ionospheric monitoring over Europe at the Royal Observatory of Belgium using GNSS dataNicolas Bergeot, Jean-Marie Chevalier, Carine Bruyninx, Eric Pottiaux, Wim Aerts, Quentin Baire, Juliette Legrand, Pascale Defraigne and Wei HuangJ. Space Weather Space Clim., 4 (2014) A31DOI: https://doi.org/10.1051/swsc/2014028