Application of blind system identification in acoustic source location

In the traditional acoustic source location methods based on correlation technique, the acoustic signal propagation velocity is a prerequisite that has to be known beforehand. However, in practice, the prerequisite is not always available. Thus, the correlation based location methods are infeasible. Actually the acquired acoustic signals contain the characteristics related to the acoustic propagation channels, thus the blind system identification strategy is applied to estimate the transmission performances of acoustic channels. Due to the long impulse responses of acoustic channels, the overlap-save and cross-correlation fitting techniques are utilized in blind system identification to estimate the acoustic channels under a built constraint condition. The times due to the propagation of the acoustic source signal from the emission point to either sensor are extracted from the identified acoustic channels. Consequently, for acoustic source location, even if the information of propagation velocity is not available, the acoustic source point can be located. In order to avoid converging to the local minima, the genetic algorithm is adopted to optimize the channel identifications. The scheme has been practically employed to locate acoustic source without the prior knowledge of propagation velocity.