Near-Field and Far-Field Estimation of Two-Dimensional Source Bearing by Microphone Array

• Main Authors: Yu- Hong Weng, 翁瑜宏
• Other Authors: Rong-Juin Shyu
• Format: Others
• Language: zh-TW
• Published: 2001
• Online Access: http://ndltd.ncl.edu.tw/handle/68067496552813336669

碩士 === 國立海洋大學 === 系統工程暨造船學系 === 89 === Abstract In this thesis, a research was carried out to investigate the performance of MUSIC method for estimating the direction of arrival of a stationary narrow band sound source. These sound sources can be in the far field and in the near field. Experiments were performed in an anechoic room and in a water tank to validate its reliability for estimating direction of arrival. First in an anechoic room, an omni-directional speaker was used as a sound source. In the far field experiment, 1-D uniform microphone array was employed to identify the source location characterized by azimuth angle. And then a 2-D uniform microphone cross array was used to locate the source in the far field characterized by azimuth angle and elevation angle. As for the near field experiment, we use 1-D uniform microphone array to identify the source location characterized by azimuth angle and range. To validate the same estimation procedure for the sound wave in water, experiments were performed in a water tank, a B&K 8105 hydrophone was used as sound source. 1-D and 2-D uniform hydrophone array were used to locate the source in the far field space, characterized by azimuth angle and elevation angle. These experiments show that 1-D far field bearing and 2-D near field bearing and range can be correctly estimated by MUSIC method. In water tank experiment, because of reflecting waves, only the far field experiments were successful, and absorbing material in the boundaries can reduce estimation error. Keywords: array signal processing、far field、near field、multiple signal classification (MUSIC)、anechoic room、water tank、direction of arrival.