Estimation for Amplitude Decrease of Discretized Hydrophone Output Voltage by Imperfect Synchronous Averaging Using External Trigger

摘要

An estimation using a theoretical formula for the amplitude decrease of discretized hydrophone output voltage due to imperfect synchronous averaging using an external trigger in our ultrasonic field parameter calibration is described. The estimation formula is derived from a statistically expected value considering the temporal difference of the trigger as a random variable with a uniform distribution in the range of the sampling period. As a result of comparing the formula and the measured hydrophone output voltage amplitude for ultrasound up to 20 MHz, it is confirmed that the formula can estimate the amplitude decrease and be used for correction to obtain accurate ultrasonic field measurement.