Iterative positioning of microphone arrays for acoustic imaging

• Published in: Journal of sound and vibration Vol. 469; p. 115116
• Main Authors: Gilquin, Laurent, Lecomte, Pierre, Antoni, Jérôme, Le Magueresse, Thibaut, Marteau, Clément
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier Ltd 17.03.2020; Elsevier Science Ltd; Elsevier
• Subjects: Acoustic imaging; Acoustics; Algorithms; Applications; Arrays; Bayesian analysis; Ill posed problems; Inverse method; Inverse problems; Mathematics; Mechanics; Microphones; Physics; Sound pressure; Sound sources; Statistics
• ISSN: 0022-460X; 1095-8568
• DOI: 10.1016/j.jsv.2019.115116

For the characterization of acoustic sources, a common approach is to retro-propagate the sound pressure measured with a microphone array, which is often performed through the resolution of an inverse problem. The ill-posed nature of this problem, as well as the limited number of measurements, are known to reduce the quality of the source reconstruction. A practical solution to these limitations is to increase the number of measurements with new array placements. However, finding the best array positions is not a straightforward process. The present paper tackles this issue by introducing a sequential approach that selects at each iteration the optimal array placement. The proposed approach builds on two features rooted in a Bayesian framework: an inverse method called “Bayesian focusing” and a Bayesian search criterion based on the Kullback-Leibler divergence. Simulations results for the characterization of a directive source are used to illustrate the performance of the approach. It is shown that for a fixed number of iterations, the proposed approach performs better than ones where the successive placements are randomly selected around the source, or others where the placements follow a deterministic spherical grid pattern.