Measurement Of Directivity Of Vector Hydrophone On A Small Water Tank

At present,there are several methods for directivity calibration of vector hydrophone at home and abroad.The vector hydrophone directivity is calibrated at high frequency in the anechoic tank while at low frequency by using standing wave tube(SWT)calibration systems.However,with many new types of vector hydrophone appeared,the SWT cannot be calibrated some large size low frequency vector hydrophone.Therefore,the new method for measuring directivity of vector hydrophone should be studied.By analyzing the distribution of sound field in the small water tank,it can be concluded that a large number of normal modes exist in the sound field.It can be seen from the relevant references that the calibration of the vector hydrophone directivity can be performed in a stable time invariant sound field.In this paper,the directivity of high-frequency and low-frequency vector hydrophone are measured in a small water tank,and the directivity of high-frequency vector hydrophone are measured in an anechoic tank while the directivity of low-frequency vector hydrophone are measured in the STW,respectively.A large number of test data showed that the vector hydrophone directional pattern measurement can be completed in a small water tank,the results obtained with the conventional measurement method is basically the same directional pattern.Therefore,the directivity measurement of the vector hydrophone in a small water tank can solve the problem of frequency limitation of vector hydrophone calibration in SWT and anechoic tank,and the measurement system is easy to establish and low cost as well.