Observatory of Athens operates one of the most advanced European
real-time ionospheric stations, a Digisonde Portable Sounder - 4D (DPS-4D)
at Penteli site (38oN, 23.5oE).
For more details on the instrumentation, see Athens
The visitors of this website can access real time observations
updated every 2 min as well as archived observations from the
The SAO Long-term
Archive tool gives access to all archived observations of the
Athens Digisonde in SAO
format. Users can also display time plot series of all
available ionospheric characteristics.