Target echo signals are the main information source in underwater acoustic detection system.

目标回波信号是水声探测系统主要的信息来源。

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This is a kind of sonar - an echo-location system.

这是一种声纳装置，一种回声定位系统。

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This is a kind of sonar - an echo-location system.

这是一种声纳装置，一种回声定位系统。

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