The NeQuick model is the ionospheric mo del that will be used by the GALILEO single frequency user to compute ionospheric corrections. In this framework, the aim of this study is to show a preliminary assessment of the performance of the NeQuick model using as metrics an independent source of TEC (Total Electron Content) such as altimetric satellites (in this case, TOPEX/Poseidon) that provide direct measurements of TEC.