Design of an accelerometer to maximize the performance of vector hydrophones

Abstract

In this study, the optimum structure of a shear type accelerometer is designed to maximize the performance of a vector hydrophone used for a towed array sonar system. The effect of the structural elements of the accelerometer on the receiving voltage sensitivity (RVS) of the hydrophone is analyzed, and the optimal structure of the accelerometer is derived based on the analysis. The RVS of the acceleration designed by the optimization is -204.9 dB, which satisfies the design specification. In addition, it is confirmed that the accelerometer with the optimum structure has the dipole mode beam pattern required for a vector hydrophone. The dipole response when coupled with an omnidirectional hydrophone can generate a cardioid beam pattern that can detect not only magnitude of a sound pressure but also the direction of the external sound source. Precedent works have presented the concept of the vector hydrophone and proved its functionality without detailed design of its structure so far. This work is new in that we carried out full detailed design process to maximize the performance of the vector hydrophone based on the analysis of the effect of structural parameters constituting the accelerometer.