HUI Juan HU Dan HUI Junying YIN Jingwei 

(College of underwater Acoustic Engineering of Harbin Engineering University Harbin 150001) 

Received Apr.4, 2007 

Revised Jun.27, 2007  

Abstract  A method using focused beamforming to measure the distribution image (underwater image) of submarine and surface ship's noise sources is presented. Level linear array can measure the target image on water level, but the multi-path interference of underwater acoustic channel may affect the quality of it. Virtual time reversal mirror and virtual array can both solve the problem very well; they make the image with high resolution.