Abstract
In this paper, a beamforming correction for dipole source identification by means of phased microphone array measurements is proposed and validated by numerical simulation. Conventional beamforming algorithms are normally based on the monopole source assumption, and can result in significant misinterpretation when applied directly to array measurements of dipole sources. A previous correction technique aims to realign the phases of microphone signals, and has been proved effective to retrieve dipole locations. However, this technique is only applicable to a single source with a linear microphone array and thus its applications are limited in practice. This work extends the signal correction technique to account for both source location and source power for 2-D microphone arrays. A dipole characteristic term is obtained based on theoretical analysis and used for the correction of both signal phase and amplitude. Numerical simulations are performed for a ideal dipole source and a reference monopole to validate the improved beamforming correction. Simulation results have shown that the proposed correction technique is capable of reconstructing dipole sources in both location and amplitude. It is therefore suggested to carefully consider the source mechanisms of aeroacoustic systems before applying array measurements.