ИСТИНА

We analyzed the occurrence of TEC fluctuations and an impact of auroral disturbances on the Precise Point Positioning (PPP) errors in European sector using GPS measurements of EPN network. Index AE was used as indicator of auroral activity. The fluctuation activity was evaluated by indexes ROT and ROTI. The positioning errors were determined using the GIPSY-OASIS software (http://apps.gdgps.net). The Precise Point Positioning is the processing strategy of the single receiver for GNSS observations that enables the efficient computation of the high-quality coordinates. For quiet conditions the algorithm provided for TRO1 stations daily average PPP errors less than 4-5 sm. The analysis indicated regular increasing positioning errors around MLT (22 UT) during March 2015. While raising the auroral activity it was observed increasing TEC fluctuation as well as positioning errors. In the report we discus also behavior PPP errors during super storm 17 March 2015. During storm at TRO1 the PPP errors reached more than 20 m. The increasing errors were observed on latitudes low than 52-54○N.