The sensitivity of the PVDF hydrophone was extracted at
intervals of 1 MHz (NTR Systems, Inc.), and we obtained the
sound pressure at the testing point from this calibration data. The
data processing procedures that we used to obtain the sensitivity
of our sensor were as follows: (1) we first measured the output
voltage taken from the PVDF hydrophone at the testing point; (2)
using the output voltage, we could then obtain the sound pressure