REPLAY - SSE9 - Florence TUPIN

SAR (Synthetic Aperture Radar) images are invaluable data for earth observation. They are obtained by emitting electro-magnetic waves with GHz frequencies, which are then backscattered by the earth surface and recorded by the antenna on a plane or a satellite. These images can be acquired at any time, regardless of the meteorological conditions, and provide information on the characteristics of the earth, its height, and its possible movement thanks to the phase information of the backscattered electro-magnetic field. A new generation of SAR sensors from state or private companies is currently imaging the earth with unprecedented spatial and temporal resolutions. Due to the coherent imaging of the SAR sensors, images present strong fluctuations due to the speckle phenomenon. This phenomenon is a major obstacle for the analysis and understanding of SAR images.

In her talk, she first introduced the principles of SAR imaging and presented some of the successful applications for cartography, height retrieval and ground movement monitoring. Advantages and drawbacks compared to optical systems were discussed. In the second part of he talk, she focus edon SAR data statistics and speckle reduction. She gave an overview of despeckling methods from those based on signal modeling through variational models or patches, to more recent ones based on deep learning with supervised and self-supervised strategies.