Sound Field Features in the Coastal Zone of a Shallow Sea with an Airborne Source of Excitation

Abstract

Features of the sound field in the coastal zone are theoretically investigated in the case of a moving airborne sound source. It is shown that two factors govern the drastic increase in the signal level measured at the observation point when the source moves near the shoreline: the directional property of the field transmitted from the air into the water and the structure of the normal wave in the wedge near the caustic. The magnitude of the increase in the sound field level depends on the depth of the reception point and, what is more essential, on the structure of the bottom.