CoAuthors

Thomas Moreau (CLS, France); Matthias Raynal (CLS, France); Pierre Thibaut (CLS, France); Craig Donlon (ESA, The Netherlands); Franck Borde (ESA, The Netherlands); François Boy (CNES, France); Nicolas Picot (CNES, France); Sébastien Clerc (ACRI-ST, France)

The Sentinel-3 mission is a two-satellite operational system designed to provide wide coverage and high-quality data for the Copernicus environmental monitoring programme. Sentinel-3B, the second satellite of this system, has been successfully launched in April 2018, and before being inserted into its final orbit (at ±140° to its twin, Sentinel-3A), has been positioned in a four-month-long close formation with S3A, during which the two satellites were observing the same scene a mere 30 seconds apart. Such flight configuration was designed to perform very accurate cross-calibration of the Sentinel-3 constellation instruments, in order to produce homogeneous and unbiased time-series observations for climate record as requested by the user community.
Being the first SAR-mode tandem phase, the Sentinel-3 tandem phase offers an unprecedented opportunity to go further into the characterization of SAR-mode signals over ocean. By exploiting the time lag between the datasets, the signals related to rapidly evolving phenomena, like propagating swells, surface heterogeneities and surface motion, can be identified in a more efficient way than with a mono-satellite dataset. The spectral signature of these signals is discussed. Both operational unfocused data and high-precision fully-focused data have been processed and analyzed at both local and global scale.
This presentation reports the most significant findings emerging from this study based on joint use of S3A and S3B satellites in tandem phase configuration, and on the exploitation of the unfocused and focused SAR processing.