The European DIgital Upper Atmosphere Server (DIAS) aims at the development of a European digital data collection on the state of the upper atmosphere and on the efficient promotion of this collection to all possible users. The establishment of DIAS was funded by the European Commission, in the frames of the eContent Programme (2004 - 2006), coordinated by the Ionospheric Group of the National Observatory of Athens, and implemented – in its initial phase - with the participation of RAL, SRC, IRF, INTA, IAP-L and INGV. In 2012 the European Space Agency approved the integration of the DIAS products in the SSA SWE network under the European Ionosonde Service (EIS). In its current edition, DIAS provides ionograms, daily plots and maps for real-time ionospheric specification, for the long-term prediction frequency planning, for the nowcasting frequency management and warning purposes and for trans-ionospheric propagation.
Several web-based tools are provided to generate ionospheric data and products for nowcasting, forecasting and postprocessing purposes. The tools provide access to ionograms and to ionospheric characteristics obtained from ionograms autoscaling. Observations from all European Digisonde stations that provide data with open access are exploited in these web-based tools. Several products for the nowcasting of the electron density profile and for the detection of Travelling Ionospheric Disturbances, are generated with ionospheric models that use, in addition to Digisonde data, supplementary data of the Total Electron Content (TEC) and data of solar and geomagnetic indices.
The DIAS Service is provided by the National Observatory of Athens.