How to estimate the Green’s function of a heterogeneous medium between two passive sensors? Application to acoustic waves

TLDR

The exact Green’s function of a heterogeneous medium can be retrieved from the cross‑correlation of fields received by two passive sensors, and this approach has applications in geophysics and ocean acoustics. The study proposes a physical interpretation of Green’s function retrieval based on time‑reversal symmetry. The method addresses causality and demonstrates how multiple scattering contributes to Green’s function reconstruction. Ultrasonic experimental results illustrate the proposed approach.

Abstract

The exact Green’s function of a heterogeneous medium can be retrieved from the crosscorrelation of the fields received by two passive sensors. We propose a physical interpretation based on time-reversal symmetry. We address the issue of causality and show the role of multiple scattering for the reconstruction of the Green’s function. Ultrasonic experimental results are presented to illustrate the argument. Applications to geophysics and ocean acoustics are discussed.