Interference structure of the field of infrasonic directed sources in shallow water

The effect of the beam pattern of sources on the spatial interference structure of the infrasonic field in shallow water has been studied numerically. Calculations have been performed for a monopole and differently oriented dipoles and quadrupoles in the near-field zone, where the modes have not yet formed, as well as in the far-field zone, where the mode interference is observed. Dependence of the interference patterns at different frequencies on the emission and reception horizons, the multipole type, and the wave distance has been demonstrated. The importance of taking into account the horizontal beam pattern of sources in the far-field zone has been shown.