Wind Retrieval Accuracy Analysis of HY-2B Microwave Scatterometer

HY-2B microwave scatterometer(HY-2B/SACT) is a Ku band rotating pencil-beam scatterometer that carried on-board the HY-2B satelllite. This paper constructed a retrieval algorithm of operational wind fields for HY-2B/SACT. Microwave scatterometer wind field inversion uses its L1B product. To prepare the sigma0 measurements for conducting wind vectors retrieval, the time ordered L1B product was regrouped to the sub-track aligned wind vector cells (WVCs). The maximum-likelihood estimator (MLE) was applied to retrieve wind vector for each WVC with the NSCAT-4 as geophysical model function (GMF). Furthermore, circular medium filter (CMF) is used to remove the ambiguities solutions. The sea surface wind field retrieved by HY-2B/SACT were evaluated by comparing with ECMWF wind field, in-situ measurements and NDBC buoy observations. The wind speed and wind direction retrieval accuracy is better than 1.5m/s and 19° respectively. This result showed that the wind products provided by HY-2B/SCAT are able to meet the requirements of science and operational users.