LAUSR

SARAL (Satellite with Argos and AltiKa) is the first satellite radar altimetry mission to fly a Ka-band instrument (AltiKa), which has completed 5 years in orbit on 25th February 2018. Ka-band SARAL-AltiKa suffers larger signal attenuation due to atmospheric water content and also exhibits a different relationship with wind speed than at Ku and C band. Here an augmentation of our earlier geophysical model function (GMF) that was developed based on first principles for wind speed retrieval from SARAL-AltiKa is proposed. This GMF is further augmented here, taking advantage of the co-aligned passive microwave radiometer making measurements of brightness temperature (BT) along with the primary active radar AltiKa measurements of radar backscatter (RB) and significant wave height (SWH) in conjunction with a large matched database of wind speed from Jason-2, respectively. The retrieved wind speed from currently modified algorithm provides an accuracy of 1.34 ms−1 in root mean square deviation with global buoys. Finally, the new algorithm has been used successfully in demonstrating its applicability in capturing regional to global wind field features and compared with other independent satellite measurements like OceanSat scatterometer, Jason-2 altimeter and DMSP-SSM/I radiometer.