One of the core objectives of satellite ocean environment monitoring is sustained global observation. The Chinese Ocean Color and Temperature Scanner (COCTS) aboard China’s ocean satellites serves as a remote sensing payload designed for this purpose. Currently, COCTS is equipped on the ocean color satellite series (HY-1C, HY-1D, and HY-1E), conducting daily global observations of ocean color and sea surface temperature at nadir ground sample distances (GSD) of 1.1 km (HY-1C/D) and 500 m (for HY-1E).
          COCTS follows an operational data processing workflow involving radiometric calibration, sea surface temperature (SST) retrieval, atmospheric correction, and ocean color parameter retrieval to generate global products. In its current product version, the COCTS global chlorophyll-a concentration product shows an average relative deviation of approximately 40% against in situ measurements, and 10–30% compared with similar products from MODIS and VIIRS. The root-mean-square error (RMSE) of SST against in situ data ranges between 0.5°C and 0.8°C. China's ocean color satellite data products include along-track Level-2 (L2) products and globally gridded Level-3 (L3) products. By blended the ocean color and sea surface temperature observation products from COCTS on the HY-1C, HY-1D, and HY-1E satellite constellation, it is possible to generate satellite remote sensing monitoring products with higher effective data coverage, providing viable data sources for global ocean color and sea surface temperature observation as well as global ocean climate change research.