Comparison of a Diffracting and a Non-Diffracting Circular Acoustic Array

Localization of acoustic sources has been an area of research starting primarily with underwater acoustics. Recently, localization of sources in air has become a topic of interest for automatic detection, surveillance and tracking for military applications. Other application include novel teleconference devices, specifically automatic focusing on the person currently speaking. Current technology relies on free-field localization arrays, and there is a plethora of literature on array beam-forming of these arrays. This paper introduces a new technology of diffracting arrays and novel signal processing methods for characterization of these arrays and localization of acoustic sources. The theory and experimental implementation of an acoustic diffracting array (ADA) is presented, including singular value decomposition and the effect of robustness. The results indicate that ADA results in increased localization accuracy, and more directional point spread functions due to increased magnitude and phase differences compared to a free-field array