A model of combined backscatter and Doppler shifts for surface velocity estimation from SAR images.
Johnny Johannessen(1), Vladimir Kudryavtsev(2), Bertrand Chapron(3), Fabrice Collard(4), Alexis Mouche(3), Dmitry Akimov(2) and Knut-Frode Dagestad(1)
(1) NERSC, Thormoehlensgate 47, N-5006 Bergen, Norway
(2) NIERSC, Vasilievsky Island, 199034 St. Petersburg, Russian Federation
(3) IFREMER, Z.I. Pointe du Diable, B.P. 70 Plouzane, France
(4) BOOST-Technologies, 115, rue Claude Chappe, 29280 Plouzane, France
Regular access to Doppler grid information from Envisat ASAR has been possible since mid 2007 thanks to ESA´s upgrading of the ground segment. This has led to the gradual generation of a comprehensive data base that, in turn, has opened up for better testing and development of the Doppler radar imaging model (DopRim). DopRim partitions the Doppler velocity into the relative contribution arising from the motion of the facets including the Bragg waves, the “specular points”, the breaking crests as well as the surface current. Simulated and observed normalized radar cross-sections and Doppler velocities will be presented from the supersites defined for the Gulf Stream region, the greater Agulhas Current regime, the Norwegian Coastal Current and the Iroise Sea. These DopRim results are promising suggesting that the DopRim approach can be applied and developed further to advance the use of SAR imagery in quantitative studies of mesoscale current features.
Keywords: ESA European
Space Agency - Agence spatiale europeenne,
observation de la terre, earth observation,
satellite remote sensing,
teledetection, geophysique, altimetrie, radar,
chimique atmospherique, geophysics, altimetry, radar,