Geometric calibration of distributed microphone arrays from acoustic source correspondences

Abstract

This paper proposes a method that solves the problem of geometric calibration of microphone arrays. We consider a distributed system, in which each array is controlled by separate acquisition devices that do not share a common synchronization clock. Given a set of probing sources, e.g. loudspeakers, each array computes an estimate of the source locations using a conventional TDOA-based algorithm. These observations are fused together by the proposed method, in order to estimate the position and pose of one array with respect to the other. Unlike previous approaches, we explicitly consider the anisotropic distribution of localization errors. As such, the proposed method is able to address the problem of geometric calibration when the probing sources are located both in the near- and far-field of the microphone arrays. Experimental results demonstrate that the improvement in terms of calibration accuracy with respect to state-of-the-art algorithms can be substantial, especially in the far-field.