Calibration of SARAL/AltiKa Wind Speed

Satellite with ARgos and ALtiKa (SARAL)/AltiKa is the first oceanographic radar altimeter that operates in Ka-band which is very sensitive to the atmospheric factors like liquid water and water vapor. An empirical recipe is proposed to partially compensate for this impact for the purpose of ocean surface wind speed (SWS) evaluation. The results compare well with numerical prediction model fields and in situ measurements. SARAL SWS computed using the proposed recipe shows very low bias (below 0.4 m/s). The random error at a scale of 75 km is estimated at about 1.0 m/s, which is very close to that of the Ku-band altimeters.