Authentication by polarization: a powerful anti - spoofing method Download De Wilde, Sleewaegen, Bougard, Cuypers (Septentrio) - Popugaev, Landman, Schirmer (Fraunhofer) - Egea-Roca, López-Salcedo, Seco-Granados(Univ. de Barcelona) ION GNSS 2018