Research On The Spatial Correlation Of Acoustic Vector Field For Surface-generated Noise In Range-dependent Waveguides

The spatial correlation of the noise field has an important influence on the array gain ofthe array. The purpose of this paper is to construct a model of surface-generated noise field ina three dimensional environment. Assuming the surface sources are monopoles distributedover an infinite plane parallel to the surface and located at certain depth. Based on the wavetheory and adiabatic normal mode theory, the scalar noise spectral density function is derived.According to the relationship among the acoustic pressure, particle velocity and the velocitypotential, spatial correlation function of the noise vector field in the rang-dependentwaveguide is obtained.In order to verify the reliability of the model, this model is compared with a ray modelunder the assumption of homogeneous media and rigid bottom, and correlation coefficient ofthe pressure is identical. It shows that this model is feasible on the noise field spatialcorrelation strcture analysis. The influence of the geoacoustic parameters and sound velocityprofile on the noise field has been presented.Later, range-dependent waveguide with slope bottom is introduced. Relationshipbetween the coherence structure and the slope angle is analyzed. Numerical simulation showsthat with the increase of slope angle, horizontal correlation radius decreases and the verticalcorrelation radius increases gradually.Finally, the experimental data is processed. Under the same frequency, verticalcorrelation coefficient of sound pressure agrees with the model prediction.