Research on source of phase difference between channels of the vector hydrophone

Abstract

The vector hydrophone can collect the acoustic pressure and the particle velocity information of the same point in the sound field synchronously and independently. It has four channels, which output the acoustic pressure and the projection components of the particle velocity vector along the x, y and z axes in the Cartesian coordinate system of the observed point respectively. The acoustic pressure and the particle velocity of a coherent source are completely correlated in the far-field region, and there is no phase difference between them. However, on practical measurement occasions, random phase difference exists between the output signals of different channels. Three sources of the phase difference are analyzed. Furthermore, for the case of mixed field, the correlation coefficient matrix of the output signals of different channels is deduced. For the case of interaction between the acoustic pressure receivers and the particle velocity receiver, performance of the pressure channel comprised of pressure receivers located in pairs and symmetrically is studied. In the end, the correlation coefficient matrix is verified by experimental data.