The NeQuick model genesis, uses and evolution

The genesis and evolution of the NeQuick model is reviewed from the initial ionospheric efforts made in the framework of the European COST actions on ionospheric issues to the last version of the model (NeQuick 2). Attention is given to the uses of the model particularly by the European satellite navigation and positioning systems EGNOS and GALILEO. Recent assessment studies on the performance of NeQuick 2 are also reviewed.