Ionospheric scintillations in Liege

Ionospheric scintillations are rapid fluctuations in amplitude and phase of radio signals (in particular, GNSS signals) passing through irregular structures in the ionosphere. They are often the origin of strong degradations in GNSS-based positioning. Ionospheric scintillations affecting GNSS signals are usually monitored using 2 indexes: S4 (amplitude) and σ_φ (phase). These indexes can be measured by Ionospheric Scintillation Monitors (ISM) which are GNSS receivers specifically designed for that purpose. The graphic below shows S4 and σ_φ indexes measured in Liege (Belgium) on L1(C/A) for GPS and E1 for Galileo satellites.