Underwater moving noise sources identification based on acoustic holography

Near-field acoustic holography (NAH) is a well established method for the reconstruction of sources. In this paper, the inclusion of an underwater moving medium is introduced and a new set of equations for NAH is developed. For a stationary acoustic field, the method continuously sweeps the acoustic field by using a line array of hydrophones fixed in space. This method enables the visualization of noise generated by moving noise sources and removes Doppler effect. Theoretical formulation has been systematically addressed which demonstrates how the idea of utilizing this method constructs the desired hologram. At last, the validity and the correctness of method are assessed by underwater near-field acoustic holography experiments based on measurement of horizontal line array of hydrophones. The experimental results show the merits of this method in the reconstruction of acoustic field, identification and localization of underwater moving noise sources.