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SUMMARY:Laurent Seppecher (Ecole Centrale Lyon) -- Non-convex interferomet
 ric inversion for wave scattering recovery in random media
DTSTART:20251112T093000Z
DTEND:20251112T103000Z
DTSTAMP:20260505T203400Z
UID:indico-event-15249@indico.math.cnrs.fr
DESCRIPTION:In non-homogeneous media with unknown wave speed\, it could be
  difficult to recover wave sources or scatters from measurements of the wa
 ve field at distant receivers. The Kirchhoff migration may fail\, as well 
 as the full inversion from a least squares approach. This is mainly due to
  the large dephasing occurred by the wave speed variations that especially
  affect the high frequency data..\n            In the regime o
 f smoothly varying random media\, it is known that the cross-correlations 
 between measurements at nearby receivers remain much more stable than line
 ar measurements. The interferometric inversion aims at recovering the sour
 ce directly from some of the cross-correlations called the interferometric
  data. This is a challenging\, non-convex\, quadratic problem..\n    
         In this talk\, we will discuss the conditions for the inte
 rferometric inversion to be well-posed\, and provide new recovery estimate
 s from interferometric data. We will also see that under the same conditio
 ns\, and despite the non-convexity of the problem\, a Wirtinger flow desce
 nd applied on the interferometric misfit functional “locally” converge
 s to the solution. Finally\, we will see\, in numerical examples\, that th
 is approach outperforms by far classical methods to recover sparse scatter
 s in slowly varying random environment..\n\nhttps://indico.math.cnrs.fr/ev
 ent/15249/
URL:https://indico.math.cnrs.fr/event/15249/
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