Estimation of Source Strength of Underwater Acoustic Transducer in Shallow Water by Inverse Frequency Response Function

A source strength estimation method based on the acoustic inverse frequency response function (IFRF) is proposed to solve the problem of poor accuracy of the assessment of the vibration and noise level of underwater acoustic equipment in shallow waters. This method represents the multi-channel transmission function as the interference superposition of the sound source and its multi order virtual source. The transfer matrix builds the relationship between the complex source strengths, the complex pressures at measurement points and the acoustic channel. The source strengths can be estimated accurately from the radiated acoustic field measurement based on the inversion of transfer matrix. The basic principle of the IFRF method is introduced, and the influencing factors of source strength estimation errors are analyzed, including the underwater acoustic channel estimation errors, sound pressure measurement errors, and the conditions of the transfer matrix. The results of simulation analysis and experiments on the lake are presented, the obtained source strength estimation results are in good agreement with the real values, which indicates that the proposed method is feasible and has good performance in estimating the source strength of underwater acoustic transducer.