Three dimensional microphone and source position estimation using TDOA and TOF measurements

This paper presents a three dimensional sensor and source position calibration algorithm for automatically determining the positions of individual microphones in a three dimensional space with at least one linear sub array of sensors. Time-difference of arrival measurements were obtained from a mobile sounding source. The algorithm uses a nonlinear least squares method to first calibrate the linear sub array, which is then used to determine the source locations. Once the location of the linear array and sources are obtained, the remaining three dimensional microphones are located by a linear least square solution. This method provides a means of establishing the positions of microphones for the purposes of speaker localization and acoustic beamforming applications in meeting rooms, without the need to measure the distances between microphones by manual means. Simulations and some live experiments illustrate the method.