CyIRG conducts studies on ionospheric variability and exploits various techniques on monitoring and modeling of ionospheric characteristics in support of systems such as High Frequency (HF) communication networks and Global Navigation Satellite Systems (GNSS). It is in the position to pursue this aim primarily by the main component of its infrastructure consisting of a top-edge modern digital ionosonde radar DPS-4D which is unique in the eastern Mediterranean area, and facilitates systematic near-real time high resolution ionospheric measurements. This is complemented by a HF spectral occupancy and VLF and scintillation monitoring systems, data from a network of 7 GNSS receivers and recently by an extended network of additional 130 GNSS receivers in Greece and Bulgaria through a GNSS Meteorology project that will also be used for ionospheric studies.