Directivity of hydroacoustic systems with parametric array in marine conditions

The paper presents the results of generalization of theoretical and experimental studies of the influence of hydrophysical inhomogeneities on the directional characteristics of the parametric array in the framework of problem solution of improving the efficiency of directional properties of adaptive hydroacoustic systems with parametric emitting arrays. The results of calculations of the directional characteristics of the parametric array obtained on the basis of the Khokhlov-Zabolotskaya-Kuznetsov model are compared with the results of experimental measurements of the directional properties of the parametric array. The normalized dependence of the width of parametric array beam pattern was obtained on the reduction of the difference frequency relative to the central frequency of the pump waves from 5 to 16 times. The influence of the sound velocity change on the direction properties of the parametric array was estimated. The normalized dependence of the width of beam pattern of the parametric array on the value of the sound velocity at the surface of the pump transducer was obtained. (paper)