Detailing a useful position calibration for microphone arrays

This paper details a simple and useful method for obtaining sensor coordinates in a microphone array. The scheme described herein is based on a well known technique, the multidimensional scaling, which uses distances measured between pairs of microphones to estimate their coordinates in a three dimensional space. While the classical multidimensional scaling provides a solution having the same set of distances (as the provided inputs) but with an arbitrary rotation, this work uses array previous information to obtain the least error among the estimated coordinates and the actual array. The previous information is related to the assumption that we know the nominal coordinates and to the fact that, when in field operation, the array is aligned properly. An error performance analysis is carried out for spatial arrays of four and seven microphones.