Assessment of an analytical model for sea surface wind speed retrieval from spaceborne SAR

Abstract

An analytical model based on radar backscatter theory was utilized to retrieve sea surface wind speeds from C-band satellite synthetic aperture radar (SAR) data at either vertical (VV) or horizontal (HH) polarization in transmission and reception. The wind speeds were estimated from several ENVISAT Advanced SAR (ASAR) images in Hong Kong coastal waters and from Radarsat-1 SAR images along the west coast of North America. To evaluate the accuracy of the analytical model, the estimated wind speeds were compared to coincident buoy measurements, as well as winds retrieved by C-band empirical algorithms (CMOD4, CMOD_IRF2 and CMOD5). The comparison shows that the accuracy of the analytical model is comparable to that of the C-band empirical algorithms. The results indicate the capability of the analytical model for sea surface wind speed retrieval from SAR images at both VV and HH polarization.

Acknowledgments

Radarsat-1 SAR data used in this study were processed at the Alaska Satellite Facility of the University of Alaska, Fairbanks. The ENVISAT ASAR data were received at ESA's designated Hong Kong Envisat ground station. This work was supported by the Open Fund of State Key Laboratory of Satellite Ocean Environment Dynamics through grant SOED0909, by the Knowledge Innovation Program of the Chinese Academy of Sciences through grant IAP09316 and partly by the Scientific Research Foundation of Hohai University and by the Office of Naval Research through grant N00014-05-1-0606 (for Zheng). Support for NOAA participation came from the NOAA Ocean Remote Sensing Program. We also thank the editor and reviewers for their valuable suggestions. The views, opinions, and findings contained in this report are those of the authors and should not be construed as an official NOAA or US Government position, policy, or decision.