HY-2B

HY-2B (Hai Yang 2B) is the second ocean-dynamics satellite in China's HY-2 series, operated by NSOAS. It was launched on 2018-10-25 and is in extended operational service as of early 2026. HY-2B flies in a sun-synchronous orbit; the stored altitude is 973 km from WMO/AVISO geodetic records, while CEOS records 963 km and AVISO notes phase-dependent orbit history.^[1][2][3]

The satellite carries four instruments: a radar altimeter for sea-surface height measurement; the HY-SCAT (HSCAT) Ku-band scatterometer for ocean surface wind vector retrieval; the Microwave Radiation Imager (MWRI) for passive microwave measurement of sea-surface temperature, precipitation, sea ice, and soil moisture; and a calibration microwave radiometer (CMR).^[4][5]

HY-2B is part of a multi-satellite HY-2 constellation that also includes HY-2C and HY-2D, together providing improved temporal sampling of global ocean-wind and sea-surface-height fields. Data products are distributed by NSOAS and are used by the EUMETSAT OSI SAF for operational wind services.^[2]