An acoustic imaging method for layered non-reciprocal media

TL;DR

This paper introduces a modified Marchenko imaging method tailored for layered non-reciprocal media, enabling accurate imaging of layer interfaces without artifacts from multiple scattering, based on wave propagation theory and numerical validation.

Contribution

It develops a novel adaptation of the Marchenko method specifically for non-reciprocal layered media, addressing a gap in acoustic imaging techniques for such materials.

Findings

Successfully images layer interfaces at correct positions

Eliminates artifacts caused by multiple scattering

Demonstrates effectiveness through numerical example

Abstract

Given the increasing interest for non-reciprocal materials, we propose a novel acoustic imaging method for layered non-reciprocal media. The method we propose is a modification of the Marchenko imaging method, which handles multiple scattering between the layer interfaces in a data-driven way. We start by reviewing the basic equations for wave propagation in a non-reciprocal medium. Next, we discuss Green's functions, focusing functions, and their mutual relations, for a non-reciprocal horizontally layered medium. These relations form the basis for deriving the modified Marchenko method, which retrieves the wave field inside the non-reciprocal medium from reflection measurements at the boundary of the medium. With a numerical example we show that the proposed method is capable of imaging the layer interfaces at their correct positions, without artefacts caused by multiple scattering.