INTERGEO Agenda - english

The GEPOS service of the Federal Agency for Cartography and Geodesy (BKG) provides PPP-RTK corrections for the whole area of Germany. Since the transition from its test phase to its optimization phase at the start of 2025, the PPP-RTK data streams have been available free of charge. We have investigated what information on ionospheric disturbances can be extracted from these datasets. The I95L-Index, first introduced in the early 2000s, quantifies expected ionospheric influences on centimeter-accurate positioning within regional GNSS reference station networks. Low I95L values indicate that fast and reliable carrier-phase ambiguity fixing should be feasible. For all those reference stations which are surrounded by three neighbours, ionospheric residual errors are estimated by comparing interpolated and actual observations. Our approach solely relies on the high-resolution gridded ionospheric corrections from GEPOS PPP-RTK, reducing computational overhead while resolving spatially detailed residual ionospheric effects. The I95L-Index is defined as the 95th percentile of residual ionospheric errors across all available satellite signals, expressed in 0.1 TECU (Total Electron Content Units). We present a near-real-time disturbance warning framework exploiting the continuous PPP-RTK data stream as an improved information source for future uses. Results are visualized as a map of Germany divided into six regions alongside a diurnal histogram, both with a temporal resolution of 15 minutes. Typical ionospheric activities, such as TIDs (especially MSTIDs) and scintillations, are clearly detectable, highlighting the value of real-time, high-resolution PPP-RTK data.