Localization of point scatterers via sparse optimization on measures

Fuente: arXiv
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Autores principales: Alberti, Giovanni S., Petit, Romain, Santacesaria, Matteo
Formato: Preprint
Publicado: 2024
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author Alberti, Giovanni S.
Petit, Romain
Santacesaria, Matteo
author_facet Alberti, Giovanni S.
Petit, Romain
Santacesaria, Matteo
contents We consider the inverse scattering problem for time-harmonic acoustic waves in a medium with pointwise inhomogeneities. In the Foldy-Lax model, the estimation of the scatterers' locations and intensities from far field measurements can be recast as the recovery of a discrete measure from nonlinear observations. We propose a "linearize and locally optimize" approach to perform this reconstruction. We first solve a convex program in the space of measures (known as the Beurling LASSO), which involves a linearization of the forward operator (the far field pattern in the Born approximation). Then, we locally minimize a second functional involving the nonlinear forward map, using the output of the first step as initialization. We provide guarantees that the output of the first step is close to the sought-after measure when the scatterers have small intensities and are sufficiently separated. We also provide numerical evidence that the second step still allows for accurate recovery in settings that are more involved.
format Preprint
id arxiv_https___arxiv_org_abs_2402_00737
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle Localization of point scatterers via sparse optimization on measures
Alberti, Giovanni S.
Petit, Romain
Santacesaria, Matteo
Numerical Analysis
We consider the inverse scattering problem for time-harmonic acoustic waves in a medium with pointwise inhomogeneities. In the Foldy-Lax model, the estimation of the scatterers' locations and intensities from far field measurements can be recast as the recovery of a discrete measure from nonlinear observations. We propose a "linearize and locally optimize" approach to perform this reconstruction. We first solve a convex program in the space of measures (known as the Beurling LASSO), which involves a linearization of the forward operator (the far field pattern in the Born approximation). Then, we locally minimize a second functional involving the nonlinear forward map, using the output of the first step as initialization. We provide guarantees that the output of the first step is close to the sought-after measure when the scatterers have small intensities and are sufficiently separated. We also provide numerical evidence that the second step still allows for accurate recovery in settings that are more involved.
title Localization of point scatterers via sparse optimization on measures
topic Numerical Analysis
url https://arxiv.org/abs/2402.00737