Geometric calibration of distributed microphone arrays

Computational auditory scene analysis exploits signals acquired by means of microphone arrays. In some circumstances, more than one array is deployed in the same environment. In order to effectively fuse the information gathered by each array, the relative location and pose of the arrays needs to be obtained solving a problem of geometric inter-array calibration. We consider the case where the arrays do not share a synchronous clock, which impairs the use of time-difference of arrival measures across arrays. Conversely, each array produces an acoustic image, which describes the energy of acoustic signals received from different directions. We jointly consider acoustic images acquired by the different arrays and adapt computer vision techniques to solve the calibration problem, thus estimating the location and pose of microphone arrays sensing the same auditory scene. We evaluate the robustness of the calibration process in a simulated environment and we investigate the effect of the various system parameters, namely the number of probing signal locations, the resolution of the acoustic images, the non-ideal intra-array calibration.