The CDN1 transponder Cal/Val site has been established on the mainland in west Crete under a triple cross-over of Sentinel-3A & 3B but also Jason series.
A microwave transponder, a microwave radiometer, two global navigation satellite system (GNSS) stations and two meteorological stations comprise the main instrumentation of the CDN1 Cal/Val site. Hybrid power supply systems (solar, wind, diesel generator and batteries) provide continuous, safe and stable power to these instruments.
The CDN1 transponder Cal/Val site has been operational since September 2015. Till 18-Oct-2019 253 transponder calibrations had been taken place for Sentinel-3A Pass No.014 (48 calibrations), Sentinel-3B (17 calibrations), CryoSat-2 (32 calibrations) and Jason Pass No.18 (156 calibrations). From these calibrations, 233 were successful whereas 20 had been cancelled mainly because of extreme weather conditions that could have put the transponder’s safety at risk.