Sound Source Localization using Cylindrical Nearfield Acoustic Holography

Nearfield Acoustic Holography (NAH) is an acoustic imaging technique used for the detection and estimation of fields of acoustic sources. Cylindrical acoustic holography is especially used for localization of acoustic sources on a cylindrical surface. A known source (speaker) was reconstructed using two different approaches, namely direct NAH and multi-reference scan based NAH, in an anechoic environment. Experimental setup consisted of 32 microphones placed on a cylindrical array, connected to a data acquisition system and a post-processor. Acoustic pressure measured by the microphone was used to reconstruct pressure, velocity and intensity fields on the cylindrical surface at different radii. Source is characterized based on Sound Pressure Level (SPL) and Directivity. Farfield pressure and directivity were estimated separately for both the cases and was validated by directly measuring the pressure in the farfield. In full paper SPL and directivity results at different frequencies and reconstruction distances will be presented.