Ionospheric activity forecast map


With increased ionospheric activity from Solar Cycle 25, it can be challenging to determine if your GNSS tracking and positioning are being impacted by the ionosphere or other interference sources.

Total electron content (TEC) is the number of electrons along the signal path between a satellite and a receiver. Elevated TEC values and in particular a high rate of change of TEC index (ROTI) are indicative of ionospheric scintillation — rapid fluctuations in GNSS signals — meaning possible impact to GNSS positioning accuracy and availability. 

TEC can fluctuate daily as solar activity excites regions of the ionosphere. TEC also has a seasonal variation and is influenced by the Earth’s geomagnetic field. This causes the values to differ by latitude, longitude, season or solar cycles, which is why we see variations in ionospheric scintillation impacts depending on geography and time of year.

The below map displays TEC and ROTI values from the past seven days and forecasts TEC values for the next 72 hours. These values are updated once a day at midnight UTC. You can view specific days or set a lower limit threshold by moving the upper or lower dial on the bottom, respectively. Toggle between TEC and ROTI values and 2D and 3D views using the buttons at the top. 

The TEC data was obtained through the online archives of the Crustal Dynamics Data Information System (CDDIS), NASA Goddard Space Flight Center, Greenbelt, MD, USA.

The ROTI data was obtained from the Ionosphere Monitoring and Prediction Center (IMPC) operated by the German Aerospace Center (DLR). We thank the DLR who maintain the IMPC services. IMPC Website: Rate of Change of TEC Index (