DETECTION OF UNDERWATER SUSPENDED MATTER

摘要

PURPOSE:To easily and surely detect presence of underwater suspended matter by comparing the wave form of ultrasonic wave received with an ultrasonic wave receiver with the wave form of ultrasonic wave oscillated from an ultrasonic wave oscillator and detecting the suspended matter from difference of both wave forms. CONSTITUTION:Firstly intensive ultrasonic wave 5 is oscillated toward an ultra sonic wave receiver from an ultrasonic wave oscillator 3. Then the wave form of ultrasonic wave received by the ultrasonic wave receiver 4 is compared with the wave form of ultrasonic wave oscillated from the oscillator 3 or the wave form of ultrasonic wave received when underwater suspended matter does not exist. Existence of medusas 6 is detected from the difference of both wave forms. In other words, the ultrasonic wave oscillated from the oscillator 3 is pressure propagation wave. Sound is changed into a nonlinear form between one period of ultrasonic wave by the nonlinear acoustic propagation characteristics for the pressure of an organism in the place wherein medusas float. When medusas 6 exist midway, the wave form of received ultrasonic wave is changed as shown in a curve (b). When the curves (a), (b) are compared, both curves differ as shown in the figure.