tailieunhanh - Báo cáo hóa học: " Acoustic Source Localization and Beamforming: Theory and Practice"

Tuyển tập báo cáo các nghiên cứu khoa học quốc tế ngành hóa học dành cho các bạn yêu hóa học tham khảo đề tài: Acoustic Source Localization and Beamforming: Theory and Practice | EURASIP Journal on Applied Signal Processing 2003 4 359-370 2003 Hindawi Publishing Corporation Acoustic Source Localization and Beamforming Theory and Practice Joe C. Chen Electrical Engineering Department University of California Los Angeles UCLA Los Angeles CA 90095-1594 USA Email jcchen@ Kung Yao Electrical Engineering Department University of California Los Angeles UCLA Los Angeles CA 90095-1594 USA Email yao@ Ralph E. Hudson Electrical Engineering Department University of California Los Angeles UCLA Los Angeles CA 90095-1594 USA Email ralph@ Received 17 February 2002 and in revised form 21 September 2002 We consider the theoretical and practical aspects of locating acoustic sources using an array of microphones. A maximumlikelihood ML direct localization is obtained when the sound source is near the array while in the far-field case we demonstrate the localization via the cross bearing from several widely separated arrays. In the case of multiple sources an alternating projection procedure is applied to determine the ML estimate of the DOAs from the observed data. The ML estimator is shown to be effective in locating sound sources of various types for example vehicle music and even white noise. From the theoretical Cramer-Rao bound analysis we find that better source location estimates can be obtained for high-frequency signals than low-frequency signals. In addition large range estimation error results when the source signal is unknown but such unknown parameter does not have much impact on angle estimation. Much experimentally measured acoustic data was used to verify the proposed algorithms. Keywords and phrases source localization ML estimation Cramer-Rao bound beamforming. 1. INTRODUCTION Acoustic source localization has been an active research area for many years. Applications include unattended ground sensor UGS network for military surveillance reconnaissance or around the perimeter of a plant for intrusion detection 1