因为它们的频宽很窄，CF 信号只能描绘目标的存在，而对于一些种类的蝙蝠来说，CF 信号还能描述目标相对于蝙蝠的运动。

Because of their narrow bandwidth, CF signals portray only the target's presence and, in the case of some bat species, its motion relative to the bat's.

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本文还计算了不同的频宽内25周交流计数电码信号能量百分比。

The study in this paper will give support to the improvement of the 25Hz AC counting code cab signalling system.

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