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SUMMARY:Waveform inversion with a data driven estimate of the internal wav
 e - Liliana Borcea (University of Michigan)
DTSTART:20230202T162500Z
DTEND:20230202T171000Z
UID:TALK194566@talks.cam.ac.uk
DESCRIPTION:We study an inverse problem for the wave equation\, concerned 
 with estimating the wave speed from data gathered by an array of sources a
 nd receivers that emit probing signals and measure the resulting waves. Th
 e typical mathematical formulation of velocity estimation is a nonlinear l
 east squares minimization of the data misfit\, over a search velocity spac
 e. There are two main impediments to this approach\, which manifest as mul
 tiple local minima of the objective function: The nonlinearity of the mapp
 ing from the velocity to the data\, which accounts for multiple scattering
  effects\, and poor knowledge of the kinematics (smooth part of the wave s
 peed) which causes cycle-skipping. We show that the nonlinearity can be mi
 tigated using a data driven estimate of the internal wave field. This lead
 s to improved performance of the inversion.
LOCATION:Seminar Room 1\, Newton Institute
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