Patent ID: 8280692
Filing Date: 2012-10-02
Classification: G01S,G06F

Abstract:
1. An ultrasonic wave propagation time measuring system, comprising: an electromagnetic wave transmission unit transmitting an electromagnetic wave signal indicating transmission timing; a unit generating an ultrasonic wave drive signal by modulating an ultrasonic wave based on a pseudo-random signal with high autocorrelativity at the same time as the transmission of said electromagnetic wave signal; an ultrasonic wave transmission unit that is driven by said ultrasonic wave drive signal, and formed from a piezoelectric or magnetostrictive element for transmitting an ultrasonic wave signal of frequency higher than a fundamental frequency of said ultrasonic wave drive signal; an electromagnetic wave reception unit detecting said electromagnetic wave signal; an ultrasonic wave reception unit detecting said transmitted ultrasonic wave signal; and a data processing unit, having a waveform the same as said ultrasonic wave drive signal as a model waveform, that computes correlation values between a detected ultrasonic wave signal and said model waveform, detects a main peak value of computed correlation values, and computes ultrasonic wave propagation time from a point in time of detection of said electromagnetic wave signal and a point in time of detection of said main peak value.