# HY-2D
*missions*

## Specifications
- **operator**: nsoas
- **actual launch**: 2021-05-19
- **current status**: operational
- **orbit type**: Drifting orbit, approximately 973 km altitude, 66 degree inclination
- **revisit days**: 10
- **current geographic priority**: Global ocean dynamic environment observations
- **tasking supported**: false
- **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":"2021-05-19","current_status":"operational","orbit_type":"Drifting orbit, approximately 973 km altitude, 66 degree inclination","revisit_days":10,"current_geographic_priority":"Global ocean dynamic environment observations","tasking_supported":false,"launch_vehicle":"casc-long-march-4b"}

## Editorial
HY-2D (Hai Yang 2D) is an operational Chinese ocean-observation satellite operated by the National Satellite Ocean Application Service (NSOAS), launched on 19 May 2021 from Jiuquan. The mission flies in a drifting orbit at approximately 973 km altitude with 66 degree inclination, providing a 10-day repeat cycle for global ocean dynamic environment monitoring.[^nsoas-hy2d-launch]

The payload stack comprises a radar altimeter (ALT), a microwave scatterometer (HSCAT), a calibration microwave radiometer (CMR), a DORIS receiver for precise orbit determination, and a laser retroreflector array (LRA). HY-2D forms part of China's HY-2 series alongside HY-2B and HY-2C, supporting sea surface height measurement, ocean wind retrieval, and passive microwave sea surface characterisation.[^wmo-oscar-hy2d][^aviso-hy2d]

## Compositional position
- HY-2D --[mission_payloads]--> hy-2d-alt (products)
- HY-2D --[mission_payloads]--> hscat (products)
- HY-2D --[mission_payloads]--> hy-2d-cmr (products)
- HY-2D --[mission_payloads]--> doris-hy-2d (products)
- HY-2D --[mission_payloads]--> lra-hy-2d (products)

## Sources
- [nsoas-hy2d-launch] | HY-2D satellite launch news | https://www.nsoas.org.cn/eng/item/262.html | tier=operator-press | accessed=2026-06-14
- [wmo-oscar-hy2d] | WMO OSCAR satellite record: HY-2D | https://space.oscar.wmo.int/satellites/view/hy_2d | tier=community | accessed=2026-06-14
- [aviso-hy2d] | AVISO+ mission page: HY-2D | https://www.aviso.altimetry.fr/en/missions/current-missions/hy-2d.html | tier=agency-doc | accessed=2026-06-14

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