在一次森林调查期间，从一架飞机负载的激光雷达上扫射出一束发出大约一秒7万次脉冲的红外光从树冠层上穿过。

During a forest survey, an aircraft-borne lidar sweeps a beam that fires about 70,000 pulses a second over the canopy.

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在一次森林调查期间，从一架飞机负载的激光雷达上扫射出一束发出大约一秒7万次脉冲的红外光从树冠层上穿过。

During a forest survey, an aircraft-borne lidar sweeps a beam that fires about 70, 000 pulses a second over the canopy.

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但步进电机的效率低，拖动负载的能力不大，脉冲当量不能太大，调速范围不大。

But the step motor efficiency is low, the ability is not big, load drag pulse equivalent cannot too big, speed range is not big.

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