# China Ocean Colour and Temperature Scanner
*sensor . products*

Ocean-colour and temperature scanner flown on HY-1D.

## Specifications
- **product status**: operational
- **deployment context**: orbital
- **manufacturer**: cast
- **sensor**: {"instrument_family":"passive-optical","measurement_principle":"passive","spec_disclosure":"estimated","spectral_range_nm":{"min":402,"max":12500},"spectral_band_count":10,"swath_km":1400,"gsd_m":{"native":1100}}
- **entity type**: sensor
- **last verified date**: 2026-06-15
- **verified by**: community
- **claim status**: agency-sourced
- **provider**: cast
- **attributes**: {"kind":"sensor","product_status":"operational","deployment_context":"orbital","manufacturer":"cast","description":"Ocean-colour and temperature scanner flown on HY-1D.","sensor":"{\"instrument_family\":\"passive-optical\",\"measurement_principle\":\"passive\",\"spec_disclosure\":\"estimated\",\"spectral_range_nm\":{\"min\":402,\"max\":12500},\"spectral_band_count\":10,\"swath_km\":1400,\"gsd_m\":{\"native\":1100}}"}
- **relevance**: in-scope

## Editorial
The China Ocean Colour and Temperature Scanner (COCTS) is a spaceborne passive optical radiometer covering 10 spectral bands from 402 nm to 12,500 nm, providing simultaneous ocean-colour and sea-surface temperature measurements.[^wmo-oscar-cocts] Ground sampling distance is approximately 1,100 m.[^wmo-oscar-cocts] COCTS has flown on HY-1A, HY-1B, HY-1C, and HY-1D.[^wmo-oscar-cocts]

Swath coverage has increased across mission generations. On HY-1A the swath was 1,400 km.[^eoportal-hy1a] HY-1B achieved approximately 2,800 km through an extended scan geometry.[^eoportal-hy1b] On HY-1C and HY-1D the swath reached approximately 2,900 km.[^wmo-oscar-cocts]

The band configuration has a minor difference between HY-1C and HY-1D. Band 7 spans 730-770 nm (40 nm bandwidth) on HY-1C, and 734-754 nm (20 nm bandwidth) on HY-1D;[^eoportal-hy1c1d][^nsoas-press] all other bands are nominally identical across the two satellites. The instrument is demonstrated for ocean-colour water-leaving radiance retrieval and sea-surface temperature retrieval.[^wmo-oscar-cocts]

## Compositional position
- hy-1d (missions) --[mission_payloads]--> China Ocean Colour and Temperature Scanner
- hy-1c (missions) --[mission_payloads]--> China Ocean Colour and Temperature Scanner

## Sources
- [wmo-oscar-cocts] | WMO OSCAR instrument record: COCTS | https://space.oscar.wmo.int/instruments/view/cocts | tier=community | accessed=2026-06-15
- [eoportal-hy1a] | HY-1A mission overview, eoPortal | https://directory.eoportal.org/satellite-missions/hy-1a | tier=community | accessed=2026-06-15
- [eoportal-hy1b] | HY-1B mission overview, eoPortal | https://directory.eoportal.org/satellite-missions/hy-1b | tier=community | accessed=2026-06-15
- [eoportal-hy1c1d] | HY-1C/1D mission overview, eoPortal | https://www.eoportal.org/satellite-missions/hy-1c-1d | tier=community | accessed=2026-06-15
- [nsoas-press] | A new development journey of Ocean colour Satellites, NSOAS | http://www.nsoas.org.cn/eng/item/258.html | tier=operator-press | accessed=2026-06-15
- [wmo-oscar-hy1c] | WMO OSCAR satellite record: HY-1C | https://space.oscar.wmo.int/satellites/view/hy_1c | tier=community | accessed=2026-06-15

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Source: https://eo-atlas.org/products/sensor/cocts
Maintainer: SpectraWorks B.V. (CC-BY 4.0)