Measurement and Extrapolation Method for the Acoustic Field Distribution of Underwater Transducer

Characterization of acoustic field distribution is crucial for the calibration of underwater transducer. To obtain the pressure distributions more efficiently, a measurement system and an extrapolation method are presented. At a relative near plane, the pressure distribution is measured by automatically scanning the field with a needle hydrophone. Then the distribution in farther fields could be directly obtained by the extrapolation method, which is based on wave superposition theory. Experiment results have demonstrated the performance of the system and the extrapolation method by a 500 kHz plane transducer. The maximum average error is less than 13% in the whole testing range, and the error could be as small as 5.23% in a short extrapolation distance.