LOW FREQUENCY UNDERWATER SOUND CALIBRATION SOURCE

A LOW FREQUENCY, NON-EXPLOSIVE, SOUND SOURCE THAT USES A RADIALLYPOLED, CERAMIC, CYLINDRICAL TRANSDUCER AND OPERATES IN FLEXURAL MODES IS PROPOSED. THE TRANSDUCER IS STRIPED INTO 4 QUADRANTS. ALTERNATE QUADRANTS ARE DRIVEN IN-PHASE AND LOADED INTO THE WATER THEREBY ENHANCING ACOUSTIC PERFORMANCE AT THE LOW FREQUENCY FUNDAMENTAL FLEXURAL MODE. THE TRANSDUCER IS INSTALLED INTO A 3.5 INCH DIAMETER BY 18 INCH LONG CYLINDRICAL HOUSING. PHASE I EFFORTS ARE DIRECTED AT DEMONSTRATING THE EFFICIENCY OF THIS TRANSDUCER CONFIGURATION AND ASSESSING ITS PERFORMANCE AT DEPTH. PHASE II EFFORTS WILL BE DEVOTED TO MAXIMIZING THE EFFICIENCY OF THIS COMPOSITE TRANSDUCER AND TO ITS PACKAGING FOR SHALLOW OR DEEP WATER APPLICATIONS AS A 500 HERTZ, 1 WATT SOUND SOURCE.