Observations of wind and ocean wave fields using ERS Synthetic Aperture Radar imagery

Abstract

The aim of the research reported here is to evaluate Synthetic Aperture Radar (SAR) capability to estimate the wind vector and associated directional wave spectrum. Two ERS–2 SAR images of the Mediterranean Sea, one over the Sicily Channel and one over the Ligurian Sea, were selected as case studies. Wind speed was estimated using SAR calibrated backscatter response, in conjunction with empirically derived ERS scatterometer models such as CMOD4 and CMOD–IFREMER. The predictions of these models were then compared with the actual sea surface wave spectra either provided by in situ measurements or resulting from the inversion of the SAR image spectrum. SAR-detected effects of both wind and wave features, induced either by atmospheric boundary layer instability or by land shadowing, were also used as reliable indicators of wind direction.

Acknowledgments

The Italian Hydrological and Marine Survey (SIMN, Servizio Idrografico e Mareografico Nazionale) is acknowledged for providing the directional wave data used for this study. ERS SAR data shown are ESA copyright. This research was supported by the Italian Space Agency (ASI).

Notes

An updated version of a paper originally presented at Oceans from Space ‘Venice 2000’ Symposium, Venice, Italy, 9–13 October 2000.