Travelling Ionospheric Disturbances (TIDs) are plasma density fluctuations that propagate as waves through the ionosphere at a wide range of velocities and frequencies. TIDs constitute a threat for operational systems using predictable ionospheric characteristics as they can impose significant disturbances in the ambient electron density and Doppler frequency shifts on HF signals. TIDs can have multiple effects in the operation of aerospatial and ground-based infrastructures and especially in the European Geostationary Navigation Overlay Service (EGNOS) and Network Real-Time Kinematic (N-RTK) services, in High Frequency (HF) communications, in radio reconnaissance operations and in Very High Frequency – Ultra High Frequency (VHF-UHF) radiowave propagation.
gAGE/UPC is a member of the TechTIDE consortium, providing support and solutions based on the knowledge and experience of the group in Ionospheric Models, Mapping Functions, Electron Density Profiles form RO, Data Analysis, TEC Variability and GNSS performance analysis. Within this project, two monitors operating in real-time has been developed and launched in order to mitigate the impact of ionospheric disturbances caused by TIDs in GNSS users: The Along ArcTEC Rate (AATR) index and the Medium Scale TID (MSTID) index.
Access to real-time and historical data are allow at the following links (prior request at info.gage [at] upc.edu ):