Craig Donlon (ESTEC/ESA, The Netherlands); Constantine Mavrocordatos (ESTEC/ESA, Netherlands); Ilias N. Tziavos (Aristotle University of Thessaloniki, Greece); Jean-Damien Desjonqueres (CNES, France); Demitris Galanakis (Space Geomatica Ltd., Greece); George Vergos (Aristotle University of Thessaloniki, Greece); Ole Andersen (DTU Space, Denmark); Achilles Tripolitsiotis (Space Geomatica Ltd., Greece); Nicolas Picot (CNES, France); Xenofon Fratzis (Technical University of Crete, Greece); Hailong Peng (National Ocean Satellite Application Center, China)

This work presents and compares the latest altimeter calibration results for the Jason series as well as the SARAL/AltiKa and the Chinese HY-2 missions, conducted at the Gavdos/Crete calibration/validation facilities. At first, the Jason altimeter calibration values will be given for the ascending Pass No.109 and the descending Pass No.18 and for Jason-1 (GDR-E), Jason-2 (GDR-D) and Jason-3 (IGDR-T). Secondly, these values will be cross-examined against the altimeter bias for the SARAL/AltiKa (GDR-T) satellite at Gavdos Cal/Val using its reference ascending orbit No. 571. The new Sentinel-3 altimeter calibration site will be presented as well as the first transponder results for the Sentinel-3, Jason-2, Jason-3 and Cryosat-2. Finally, the Chinese HY-2 satellite altimeter bias will be presented using the CRS1 permanent Cal/Val site in south west Crete for the descending HY-2 Pass No. 280, at 20 Hz based on SGDR data products. Additionally, altimeter biases as determined by locally developed Mean Sea Surface model will be presented and compared with the conventional sea-surface calibration methodology.