Abstract's details

Performance Characteristics of the CDN1 Transponder Data and Current Results of the ESA Permanent Facility for Altimetry Calibration in West Crete

Stelios Mertikas (Technical University of Crete, Greece)


Craig Donlon (European Space Ageancy/ESTEC, Netherlands); Dimistrios Piretzidis (Space Geomatica, Greece); Constantine Kokolakis (Space Geoamtica, Greece); Robert Cullen (European Space Agency/ESTEC, Netherlands); Pierre Femenias (European Space Agency/ ESRIN, Italy); Marco Fornari (European Space Agency, Netherlands); Francois Boy (CNES, France); Berthyl Duesmann (European Space Agency/ESTEC, Netherlands); Mingsen Lin (National Satellite Ocean Application Service, China); Yongjun Jia (National Satellite Ocean Application Service, China); Lei Yang (First Institute of Oceanography, China); Xenofon Frantzis (Technical University of Crete, Greece); Achilles Tripolitsiotis (Space Geomatica, Greece)

Event: 2022 Ocean Surface Topography Science Team Meeting

Session: Regional and Global CAL/VAL for Assembling a Climate Data Record

Presentation type: Type Oral

Contribution: PDF file


A microwave range transponder has been operating at the CDN1 Cal/Val site on the mountains of Crete for about 6 years to calibrate international satellite radar altimeters at the Ku-band. This CDN1 transponder is part of the European Space Agency Permanent Facility for Altimetry Calibration (PFAC), and has been producing continuously as of 2015 a time series of range biases for Sentinel-3A, Sentinel-3B, Sentinel-6A, Jason-2, Jason-3 and CryoSat-2. A second range and sigma-0 transponder at a crossover location of Sentinel-6 “Michael Freilich” on the island of Gavdos is also operational as of 11-Oct-2021. This work presents a thorough examination of the transponder Cal/Val responses in an effort to understand and determine which factors are responsible for the observed changes in the Cal/Val results. Fourteen uncontrolled and three controlled sources of variations have been investigated.
The latest calibration results for the Jason-3, the Copernicus Sentinel-3A and -3B, Sentinel-6A and the HY-2B radar altimeters will be described based on four sea-surface and two transponder Cal/Val sites of the PFAC in west Crete, Greece. Absolute biases for Jason-3, Sentinel-6A, Sentinel-3A, Sentinel-3B and HY-2B will be given using various techniques, infrastructure and settings.

Oral presentation show times:

Room Start Date End Date
Sala Grande Wed, Nov 02 2022,09:15 Wed, Nov 02 2022,09:30
Stelios Mertikas
Technical University of Crete