Ionosphere modeled with the NeQuick 2 driven by various space weather indices

Correct modeling of the ionospheric error plays a crucial role in position determination for single frequency Global Navigation Satellite System (GNSS) receivers. The new GNSS Galileo will use a modification of the ionospheric model NeQuick to mitigate ionospheric delay. The model will not be driven by its typical parameter but by the effective ionization level. The vertical total electron content values of the year 2011 from Space Weather Application Center - Ionosphere (SWACI) were compared to the modeled data by NeQuick 2 driven by its default drivers and by the effective ionization level. The comparisons were done for whole globe and for Croatian region to study how the global model performs in a specific area. In case of both global and Croatia data, the overall best performance showed NeQuick 2 driven by daily solar flux. However, for the days with solar flux lower then 90 solar flux units the same NeQuick showed the worst results. The ionosphere modeled by NeQuick 2 driven by ionization level was in all the cases the second best, which seems as a reasonable compromise.