TechTIDE: Warning and Mitigation Technologies for Travelling Ionospheric Disturbances Effects

Travelling Ionospheric Disturbances (TIDs) are ionospheric manifestations of internal atmospheric gravity waves (AGW) in the neutral atmosphere driven by near-Earth space dynamics and by lower atmosphere phenomena. They constitute a threat for operational systems such as precise navigation (e.g., EGNOS and NRTK) and high frequency geolocation as they can impose disturbances with amplitudes of up to ~20% of the ambient electron density, and Doppler frequency shifts of the order of 0.5 Hz on HF signals. The Horizon 2020 Project TechTIDE (http://techtide.space.noa.gr/) funded by the European Commission aims at designing and testing new viable TID impact mitigation strategies for the technologies affected by developing a system able to calculate in real-time the main TID characteristics (velocity, amplitude, propagation drection), to realistically specify background ionospheric conditions and to specify those ionospheric characteristics whose perturbation, because of TIDs, cause the impact in each specific technology. The TechTIDE system will contribute new understanding of the physical processes resulting in the formation of TIDs, and will consequently help to identify the drivers in the interplanetary medium, the magnetosphere and the atmosphere. This paper will provide a description of the instrumentation involved and outline the project methodologies for the identification and tracking of TIDs based on the exploitation of real-time observations from networks of Digisonde, GNSS receivers and Continuous Doppler Sounding Systems.