Precision and accuracy of acoustic gunshot location in an urban environment

TL;DR

This study evaluates the accuracy of acoustic multilateration for gunshot localization in urban environments, demonstrating high precision with multiple sensors and specific algorithms in real-world tests.

Contribution

It provides empirical validation of acoustic multilateration techniques for gunshot detection in urban settings, highlighting optimal algorithms and sensor configurations.

Findings

96% of shots localized within 15 meters with six or more sensors

Best results achieved using Mathias, Leonari and Galati algorithm under 2D constraints

High accuracy demonstrated in live-fire urban tests

Abstract

The muzzle blast caused by the discharge of a firearm generates a loud, impulsive sound that propagates away from the shooter in all directions. The location of the source can be computed from time-of-arrival measurements of the muzzle blast on multiple acoustic sensors at known locations, a technique known as multilateration. The multilateration problem is considerably simplified by assuming straight-line propagation in a homogeneous medium, a model for which there are multiple published solutions. Live-fire tests of the ShotSpotter gunshot location system in Pittsburgh, PA were analyzed off-line under several algorithms and geometric constraints to evaluate the accuracy of acoustic multilateration in a forensic context. Best results were obtained using the algorithm due to Mathias, Leonari and Galati under a two-dimensional geometric constraint. Multilateration on random subsets of the participating sensor array show that 96% of shots can be located to an accuracy of 15 m or better when six or more sensors participate in the solution.