Ku-Band Radar Altimeter Surface Wind Speed Algorithm

A surface wind speed retrieval algorithm from Ku-band radar altimeter backscatter coefficients is presented. It was derived using two-months of ENVISAT altimeter backscatter data collocated with ECMWF model and in situ wind speeds and was extensively verified for ENVISAT, ERS-2, and Jason-1/2 against model and in situ wind data. The algorithm performs better than the two-parameter (backscatter and significant wave height, SWH) algorithms of Jason-1/2. The success of the current algorithm raises a question regarding the usefulness of SWH alone as a second parameter for retrievals. It is argued that SWH alone is not the proper choice to represent the sea-state conditions.