Ionospheric response to extreme events and its effects on precise point positioning

One of the major error sources for Global Navigation Satellite Systems (GNSS) is the ionosphere layer. In addition to regular changes in the ionosphere, irregular changes due to space weather conditions also occur. One of the space weather phenomena is geomagnetic storm. In this study, the influence of changes in the ionosphere in case of geomagnetic storm on kinematic Precise Point Positioning (PPP) was investigated. For this purpose, 12 intense geomagnetic storms were selected between 2000 and 2018. Using the global ionosphere maps, the anomaly regions were determined and UCLP-LPGS stations were selected from the northern and southern hemispheres, respectively. The Total Electron Content (TEC) and kinematic PPP coordinates obtained at the stations on the anomaly days were examined. The results showed that the degradation level of kinematic PPP solutions depends on the intensity of the TEC fluctuations. However, in cases the TEC anomaly is low, it has no significant effect on the positioning accuracy.