On Sampling Methods for Inverse Biharmonic Scattering Problems in Supported Plates

TL;DR

This paper investigates sampling methods for inverse biharmonic scattering problems in supported plates, deriving theoretical principles and comparing the effectiveness of linear and direct sampling methods through numerical experiments.

Contribution

It introduces a reciprocity principle and a factorization of the far-field operator for supported plates, enabling analysis of sampling methods for obstacle detection.

Findings

Both LSM and DSM effectively recover obstacle location and convex hull.

DSM provides better stability and is computationally more efficient.

Methods are robust under noise, limited data, and multiple scattering conditions.

Abstract

We study the inverse problem of qualitatively recovering a supported cavity in a thin elastic plate governed by the flexural (biharmonic) wave equation, using far-field pattern measurements. We derive a reciprocity principle and a factorization of the far-field operator for the supported plate boundary conditions, and we analyze its range properties to justify both the linear sampling method (LSM) and the direct sampling method (DSM). Numerical experiments assess the performance of LSM and DSM under noise, a limited amount of data, multiple scattering, and variations in the Poisson's ratio. The results show that both methods robustly recover the obstacle's location and convex hull, with DSM offering improved stability and reduced computational cost.