CoAuthors

Mingsen Lin (National Satellite Ocean Application Service, China); Chaofei Ma (National Satellite Ocean Application Service, China); Dimitrios Piretzidis (Space Geomatica, Greece); Yongjun Jia (National Satellite Ocean Application Service, China); Lei Yang (First Institute of Oceanography, China); Xenophon Frantzis (Technical University of Crete, Greece); Constantine Kokolakis (Space Geomatica, Greece); Achilles Tripolitsiotis (Space Geomatica, Greece)

The HaiYang-2B (HY-2B) altimeter satellite has been launched by the Chinese National Satellite Ocean Application Service (NSOAS) on 24 October 2018, to monitor the marine dynamic environment. In this work, HY-2B observations have been assessed by the Permanent Facility for Altimetry Calibration in Crete, Greece and in the context of the Dragon research initiative of ESA. This action supports Earth observation research activities between European and Chinese institutes.
At first, a preliminary analysis of the HY-2B Geophysical Data Records revealed minor inconsistencies between the 1-Hz and 20-Hz products, as in the Net Instrument Correction and the Ku-band range. These have been reported to and immediately corrected by NSOAS, resulting in a consistent release of the HY-2B data.
Two years of altimetric observations of HY-2B have been calibrated using two sea-surface Cal/Val sites in Crete. Results will be given for two Cal/Val sites: the CRS1 site in the south west tip of Crete, where the descending Pass No. 66 is calibrated, and the RDK1 site in the central south Crete used for the calibration of its ascending pass No. 161. In addition, relative calibration of HY-2B has also been carried out around Crete with reference to Jason-3, Sentinel-3A and Sentinel-3B. Finally, an assessment of the HY-2B’s microwave radiometer has been performed by comparing radiometric tropospheric delays with tropospheric delays derived by the ECMWF model and the permanent GNSS stations in Crete.