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.
When passing One Fathom Bank, check the depth and variable sand waves below the sea level all the time by echo sounder.
通过一托浅滩时，要一直测深校时水深及海面下多变的沙纹。
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In the process of target detection, depth bomb fuze will undergo the interference from echo signal of neighborhood bomb that is the primary factor which causes high false-alarm probability.