Coherence-adjusted monopole dictionary and convex clustering for 3D localization of mixed near-field and far-field sources
Source localization using spherical microphone arrays has received attention due to the ease of array processing in the spherical harmonics (SH) domain with no spatial ambiguity. In this paper, we address the issue of near-field source localization using a spherical microphone array. In particular, three methods that jointly estimate the range and bearing of multiple sources in the spherical array framework, are proposed. Two subspace-based methods called the Spherical Harmonic MUltiple SIgnal Classification (SH-MUSIC) and the Spherical Harmonics MUSIC-Group Delay (SH-MGD) for near field source localization, are first presented. Additionally, a method for near-field source localization using the Spherical Harmonic MVDR (SH-MVDR) is also formulated. Experiments on near-field source localization are conducted using a spherical microphone array at various SNR. The SHMGD is able to resolve closely spaced sources when compared to other methods.