echo depth sounder

基本解釋

When passing One Fathom Bank, check the depth and variable sand waves below the sea level all the time by echo sounder.
通過(guò)一托淺灘時(shí)，要一直測(cè)深校時(shí)水深及海面下多變的沙紋。
blog.sina.com.cn
Echo Sounder is a kind of acoustic measuring depth equipment, which can measure depth with the time between transmitted wave and echo on condition in which the speed of ultrasonic is fixed.
回聲測(cè)深儀是用來(lái)測(cè)量水深的一種聲學(xué)測(cè)量設(shè)備，其以水中超聲波的傳播速度為確定條件，利用發(fā)射波與反射回波時(shí)間差來(lái)測(cè)量水深。