Comprehensive validation of wind and wave retrievals from the HY-2 constellation against buoy data

Citation

Chen J, Shao W, Marino A, Jia Y & Jiang X (2025) Comprehensive validation of wind and wave retrievals from the HY-2 constellation against buoy data. Remote Sensing Letters, 16 (11), pp. 1164-1179. https://doi.org/10.1080/2150704x.2025.2541940

Abstract
In the last 5 years, Chinese satellites, such as the HY-2 constellation, have facilitated the operational application of ocean dynamics observations. The aim of this letter is to assess the operational products of the HY-2 constellation by conducting comprehensive validation against observations from >50 moored buoys of the National Data Buoy Center (NDBC) in U.S. coastal waters. The HY-2 constellation includes Haiyang-2B/2C/2D (HY-2B/2C/2D) satellites operating in orbit currently. The wind and wave retrievals from scatterometers and altimeters onboard the HY-2 satellites in 2020–2023 were compared to the measurements from NDBC buoys in U.S. coastal waters, and it was found that the HY-2 scatterometer performed well, measuring wind speed of up to 25 m s−1, with a root mean squared error (RMSE) of less than 1.4 m s−1, a correlation coefficient (r) greater than 0.9 and a scatter index (SI) below 0.2. The error in wind speed between the HY-2 altimeters and the buoys was twice as large, with an RMSE of about 2.8 m s−1, a r below 0.7 and a SI above 0.45. Severe sea states degrade the measurement accuracy of the HY-2 satellite constellation. Specifically, HY-2D exhibits heightened sensitivity to sea state variations compared to its counterparts HY-2B and HY-2C, particularly in scatterometer-derived wind speed measurements where its accuracy declines more rapidly with increasing sea conditions. Furthermore, under severe sea states, the overall performance demonstrates a progressive deterioration as wind speed intensifies. This is compounded by the pronounced effect of significant wave height (SWH) on HY-2 altimeters, especially in low-energy sea states (SWH < 2 m).

Journal
Remote Sensing Letters: Volume 16, Issue 11