pulse sonar

例句：

1. 1. The sonar was used to detect the underwater objects.
   声纳用于探测水下物体。
2. 2. The sonar is a device that uses sound waves to detect objects in the water.
   声纳是一种使用声波探测水中物体的设备。
3. 3. The sonar can be used for underwater exploration and mapping.
   声纳可用于水下探索和地图绘制。