Validation of coastal wave and wind measurements from SARAL/AltiKa using buoys in Taiwan Strait, China

Abstract

French-Indo joint mission SARAL/AltiKa is the first space-borne altimeter operating at Ka-band, which is expected to obtain finer resolution ocean surface wind speed and significant wave height (SWH) measurements particularly in coastal areas compared to the traditional Ku-band altimeters. In this paper, we present the preliminary validation results for the SARAL/AltiKa coastal SWH and wind speed against in situ measurements from four moored buoys in Taiwan Strait, China. The temporal and spatial differences between the SARAL/AltiKa and the in situ observations were limited to less than 30 min and 10 km, yielding 73 match-up pairs for the first 25 cycles of SARAL. Comparisons show Root Mean Square Error (RMSE) of 0.28m, bias of 0.11m for SARAL/AltiKa SWH, and RMSE of 1.76m, bias of −0.79m/s for SARAL/AltiKa wind speed indicating capability of AltiKa providing SWH and wind speed products with reliable accuracy in the coastal region of Taiwan Strait, even as close as 1.5 km to the shore.