YAN Jin  LUO Xianzhi  HOU Chaohuan　

 (Institute of Acoustics, The Chinese Academy of Sciences Beijing 100080) 

Received Mar. 3, 2006 

Revised Jun. 13, 2006 

Abstract  The spatial coherences were investigated between the sound pressure and the three orthogonal components of the particle velocity in underwater ambient noise. Based on the ray theory, integral expression was derived for the spatial coherence matrix of the sound pressure and the particle velocity in a stratified ocean with dipole noise sources homogenously distributed on the surface. The integrand includes a multiplying factor of the vertical directivity of the noise intensity, and the layered ocean environment affects the spatial coherences via this directivity factor. For a shallow water environment and a semi-infinite homogenous medium, the coherence calculation results were given. It was showed that the sound speed profile and the sea bottom could not be neglected in determining the spatial coherences of the ambient noise vector field.

PACS number: 43.30