Special Session 127: Recent Advances in Inverse Problems, Imaging, and Their Applications

Reduced order model approach for imaging with waves

Josselin Garnier
Ecole polytechnique
France
Co-Author(s):    Liliana Borcea Alex Mamonov Jorn Zimmerling
Abstract:
We consider the inverse problem for the scalar wave equation. Sensors probe the unknown medium to be imaged with a pulse and measure the backscattered waves. The objective is to estimate the velocity map from the array response matrix of the sensors. Under such circumstances, conventional Full Waveform Inversion (FWI) can be carried out by nonlinear least-squares data fitting. It turns out that the FWI misfit function is high-dimensional and non-convex and it has many local minima. A novel approach to FWI based on a data-driven reduced order model (ROM) of the wave equation operator is introduced and it is shown that the minimization of ROM misfit function performs much better.