Sound source identification in the shallow water using the coherence of the vector field

Sound source identification in the shallow water is important to the performance of the sequent target detection and localization algorithms. However it's difficult to be tackled since the underwater passive acoustic sources are often distant and hidden in the noisy ambient noise. In the paper, the coherences between the pressure and different axes of the particle velocity are presented for identification of three types of sources, that is, the overhead noise in the near field, the distant ship noise, and the near/far active source. From the lake trial data, it's found that coherences between the pressure and three axes of the particle velocity are different for different types of sources. Moreover, the z-axis of a vector sensor is in favor of collecting the overhead noise propagating from the surface to the bottom. The acoustic vector sensors provide not only the directivity of the acoustic field, but also more unique information embedded in the vector properties of the acoustic field.