Retrieval of Wind and Total Surface Current Vectors Using Experimental Bidirectional Along-Track Interferometric TanDEM-X Data

Observations of wind and ocean surface velocity vectors by along-track interferometry (ATI) with the synthetic aperture radar (SAR) are not only important for direct applications but also to increase understandings upper layer mixing, air–ocean interactions, mapping submesoscale (1–10 km) structures. An experimental bidirectional (BiDi) ATI acquisition mode TanDEM-X observes two squinted beams separated an angle approximately 13.2° in azimuth on ground. The baseline is very short, interferometric phase (ATI phase) line-of-sight direction can be interpreted as a total Doppler velocity. 2-D field will thus include wind-wave detected motions. In this article, fields acquired from presented. sequential retrieval vector current (TSCV) demonstrated BiDi data. algorithm builds existing geophysical model functions (GMFs) normalized cross section (NRCS) XMOD2 GMF based Elfouhaily wave spectrum coupled Kirchhoff approximation (EOWS&KA) used. retrieved generally consistent European Centre Medium-Range Weather Forecasts (ECMWF) ERA-5. While errors small, TSCV looks promising. Acquisitions were located at sea over tip Novaya Zemlya Russia area near Tromsø, Norway.