Non-Line-of-Sight Passive Acoustic Localization Around Corners

TL;DR

This paper demonstrates that passive acoustic correlation techniques can localize and track a human around a corner without active sources, using broadband noise and Green function retrieval in reverberant environments.

Contribution

It introduces a passive acoustic NLoS localization method that replaces active sources with passive detectors leveraging broadband noise.

Findings

Successful localization and tracking of a human around a corner.

Passive detectors can replace active sources with broadband noise.

Localization achieved in reverberant room environments.

Abstract

Non-line-of-sight (NLoS) imaging is an important challenge in many fields ranging from autonomous vehicles and smart cities to defense applications. Several recent works in optics and acoustics tackle the challenge of imaging targets hidden from view (e.g. placed around a corner) by measuring time-of-flight (ToF) information using active SONAR/LiDAR techniques, effectively mapping the Green functions (impulse responses) from several sources to an array of detectors. Here, leveraging passive correlations-based imaging techniques, we study the possibility of acoustic NLoS target localization around a corner without the use of controlled active sources. We demonstrate localization and tracking of a human subject hidden around the corner in a reverberating room, using Green functions retrieved from correlations of broadband noise in multiple detectors. Our results demonstrate that the controlled active sources can be replaced by passive detectors as long as a sufficiently broadband noise is present in the scene.