_Motivation

     Electromagnetic waves carrying signals from satellites travel through the ionosphere and therefore are impacted by the ionospheric plasma and its irregularities, at frequencies up to 10 GHz. Crucially, this affects a number of applications increasingly relevant to modern society, such as satellite navigation/positioning, communications and remote sensing. Ionospheric perturbations at spatial scales ranging from a few meters up to thousands of kilometres cause signal scintillations, Travelling Ionospheric Disturbances and steep ionization gradients, which are known to cause serious performance degradation on these systems. As their performance and reliability become more and more important to the worldwide economy and society's daily activities, the need for the establishment of robust integrated services to counter these effects becomes paramount. It is therefore a common interest of all European countries to reduce ionospheric threats to radio systems operating in quite different fields of application requiring high levels of accuracy, integrity and availability.



Loss of lock of GPS signal due to strong amplitude and phase scintillation at a high latitude station (Bergen)