# HY-2B
*missions*

## Specifications
- **operator**: nsoas
- **actual launch**: 2018-10-25
- **current status**: extended
- **orbit type**: Sun-synchronous orbit, 973 km altitude, 06:00 descending equator crossing time
- **tasking supported**: false
- **current geographic priority**: Global ocean-dynamics observations, including sea-surface wind, sea-surface height and sea-surface temperature.
- **launch vehicle**: casc-long-march-4b
- **entity type**: mission
- **last verified date**: 2026-06-14
- **verified by**: agency-doc
- **claim status**: agency-sourced
- **provider**: nsoas
- **attributes**: {"operator":"nsoas","actual_launch":"2018-10-25","current_status":"extended","orbit_type":"Sun-synchronous orbit, 973 km altitude, 06:00 descending equator crossing time","tasking_supported":false,"current_geographic_priority":"Global ocean-dynamics observations, including sea-surface wind, sea-surface height and sea-surface temperature.","launch_vehicle":"casc-long-march-4b"}
- **relevance**: in-scope

## Editorial
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.[^wmo-hy2b][^aviso-hy2b][^ceos-hy2b]

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).[^wmo-hscat][^wmo-mwri-hy2]

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.[^aviso-hy2b]

## Compositional position
- HY-2B --[mission_payloads]--> hy-2b-alt (products)
- HY-2B --[mission_payloads]--> hscat (products)
- HY-2B --[mission_payloads]--> hy-2b-mwri (products)
- HY-2B --[mission_payloads]--> hy-2b-cmr (products)
- HY-2B --[related-topic]--> ocean-surface-winds (topics)
- HY-2B --[related-topic]--> sea-level (topics)
- HY-2B --[related-topic]--> sea-state (topics)
- HY-2B --[related-topic]--> sea-surface-temperature (topics)

## Sources
- [wmo-hy2b] | HY-2B, WMO OSCAR satellite record | https://space.oscar.wmo.int/satellites/view/hy_2b | tier=community | accessed=2026-06-14
- [aviso-hy2b] | AVISO+ mission page: HY-2B | https://www.aviso.altimetry.fr/en/missions/current-missions/hy-2b.html | tier=agency-doc | accessed=2026-06-14
- [ceos-hy2b] | HY-2B mission summary, CEOS EO Handbook | https://database.eohandbook.com/database/missionsummary.aspx?missionID=718 | tier=community | accessed=2026-06-14
- [wmo-mwri-hy2] | MWRI (HY-2), WMO OSCAR instrument record | https://space.oscar.wmo.int/instruments/view/mwri_hy_2 | tier=community | accessed=2026-06-14
- [wmo-hscat] | HSCAT, WMO OSCAR instrument record | https://space.oscar.wmo.int/instruments/view/hscat | tier=community | accessed=2026-06-14

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Source: https://eo-atlas.org/missions/hy-2b
Maintainer: SpectraWorks B.V. (CC-BY 4.0)