Influence of emitter's position in the field of view of the acoustic camera and ground reflection in sound source localization with beamforming

Abstract

Acoustic cameras are powerful tools that combine a video camera with a microphone array to locate noise sources. Different beamforming techniques can be applied to the acquired sound signals, allowing to visualize noise or distinguish the contribution of multiple different sources even emitting simultaneously. A procedure has been previously developed by the authors for the analytical analysis of the output images of the acoustic cameras. In fact, output images contain only visual information on the origin of the sound in the visual field of the camera, without providing analytical information about their position. The procedure allows to quantify the localized position and also evaluate the distance from the real emission point when know, making possible comparison between different acoustic camera or different beamforming algorithms. In the present work, the aforementioned procedure is applied to test measurements carried out with a known emitter in an open field to evaluate the effect that source's height from the ground and position in the field of view have in the localization with beamforming techniques.