Source Localization Based on the Doppler Effect

In this paper, we study an acoustic sound source localization scheme based on the Doppler effect. We use a circular microphone array and sample the microphones in a round robin fashion. This circular sampling corresponds to sampling a single microphone moving on a circular track. Thereby, the resulting signal contains periodic frequency shifts. By estimating these changes in the instantaneous frequency of such a circularly sampled signal, the direction of incoming wave fronts can be found in its phase alignment. In a former publication, we developed a localization algorithm based on the Teager-Kaiser energy operator (TKEO) to estimate these changes in instantaneous frequency. However, this differential operator is susceptible to noise and is only applicable for lower signal frequencies. Therefore, we present an alternative solution by means of the Center-of-Gravity (CoG) algorithm. Furthermore, we extend the scope of this approach to sound sources close to the array and inside of the array.