Acoustic transducer and underwater sounding apparatus

摘要

An acoustic transducer has an upper cylindrical portion and a lower hemispherical portion on which a plurality of transducer elements are arranged. The transducer elements on the cylindrical portion are arranged in such a way that six transducer elements adjacent to any one of the transducer elements are located at vertices of a regular hexagon and regular hexagons adjoining in a horizontal direction have sides which are oriented parallel to an axial direction (vertical direction) of the cylindrical portion. The transducer elements on the hemispherical portion are arranged at vertices of spherical triangles constituting each of spherical pentagons obtained by projecting regular pentagons together forming one half of a regular dodecahedron onto a hemispherical surface of the hemispherical portion in which the half of the regular dodecahedron is inscribed, as well as at equal division points taken on individual sides of each of the spherical triangles and at the centers of gravity of small spherical triangles formed at intersections of parallel arcs joining the equal division points of each of the spherical triangles.