Validation of SWH and SSHA from SARAL/AltiKa Using Jason-2 and In-Situ Observations

Abstract

The focus of this study is the validation of significant wave height (SWH) and sea surface height anomaly (SSHA) obtained from the first Ka-band altimeter AltiKa onboard SARAL (Satellite for ARGOS and Altimeters). It is a collaborative mission of the Indian Space Research Organization and Centre National d'Etudes Spatiales (CNES). This is done using in-situ observations from buoy and Jason-2 measurements. Validation using buoy observations are at particular locations while that using Jason-2 altimeter is an attempt towards global validation of Altika products. The results clearly indicate that the SARAL/AltiKa provide high-quality data and the errors are within a predefined range of accuracy. A parallel validation of SWH from other altimeters, which monitored ocean since last decade, like EnviSAT and Jason-2 was also performed with buoy observations. The results clearly show that the accuracy of AltiKa SWH is much better than EnviSAT and comparable to reference mission Jason-2. The accuracy is quite good for the calm sea while in the rough seas the accuracy degrades some. The inter-comparison of SARAL/AltiKa SSHA with Jason-2 indicates a fair match between them. These validation exercises demonstrate the high quality of AltiKa products, usable for practical applications.

Keywords:

• EnviSAT
• Jason-2
• Ka-band
• NDBC buoy
• SARAL/AltiKa
• validation

Acknowledgements

The authors congratulate CNES, France, and ISRO for developing SARAL/AltiKa. The authors would like to thank the director, SAC, and deputy director, EPSA, for their great support and encouragement for this work. This article would not be complete without suggestions and helps rendered by Prof. S. K. Basu.