Linear Sampling Method
This research topic is related to wave imaging techniques, which aim at reconstructing various features of a scatterer (localization, shape, nature) from multi-static data (resulting from wave emission and records at several locations).
Among inversion methods that underwent significant progress in recent years, the so-called sampling methods have become popular since they provide quick and simple inversion algorithms that are not iterative, do not rely on any linearization assumption (Kirchhoff, Born) and do not require any a priori knowledge on the physical nature of the imaged inclusions.
The first non academic works about validation of the Linear Sampling Method in three-dimensional electromagnetism were realized at CERFACS. The method has been successfully applied to reconstruct one or several metallic or dielectric objects, possibly buried in the underground.
Research activities are now focused on the following aspects:
Among inversion methods that underwent significant progress in recent years, the so-called sampling methods have become popular since they provide quick and simple inversion algorithms that are not iterative, do not rely on any linearization assumption (Kirchhoff, Born) and do not require any a priori knowledge on the physical nature of the imaged inclusions.
The first non academic works about validation of the Linear Sampling Method in three-dimensional electromagnetism were realized at CERFACS. The method has been successfully applied to reconstruct one or several metallic or dielectric objects, possibly buried in the underground.
Research activities are now focused on the following aspects:
- Real time algorithms are developed in collaboration with the Parallel Algo team.
- Information on the interior of the scatterer are extracted from the properties of the Interior Transmission Eigenvalue Problem.
Some results:
A metallic aircraft
Real aircraft (left) and reconstruction (the wavelength is indicated in blue)
Real Sigma (left) and reconstruction (right)
A burried dielectric object
The RG-LSM (RG stands for Reciprocity Gap) has been applied to reconstruct a dielectric object embedded in a substrate. The receptors are located in the air on a horizontal plane above the interface subtsrate-air (in green on the figure).
