ACOUSTIC REFLECTORS

摘要

An acoustic reflector comprises a shell surrounding a solid joint free core, said shell being capable of transmitting acoustic waves incident on the surface of the shell into the core to be focused and reflected from an area of the shell located opposite to the area of incidence so as to provide a reflected acoustic signal output from the reflector. The ratio of the speed of sound wave transmission in the shell to the average speed of the wave transmission in the core is preferably in the range of 2.74 to 3.4, inclusive or a multiple thereof with best result in the range of 2.74 to 2.86 inclusive.