It is usually expressed by the decibels which is the straight beam probe tested the second time subtracting from the first bottom surface echo amplitude.

通常用纵波直探头测试的第几次与第一次底面回波幅度所差的分贝数表示。

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By contrast, Voyager 1, the most distant functioning space probe, is using an extremely weak transmitter to beam radio messages back to earth across 10 billion miles of space.

与此形成鲜明对比的是，最遥远的旅行者1号太空飞船在飞出100多亿公里之外，还能利用极其微弱的发射器将无线电信号传回地球。

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In the paper. the interference intensity of signal laser beam and the reference one is carried out in detail on a heterodyne laser probe with amplitude modulated laser source.

本文详细推导了用振幅调制激光为光源外差激光探针的信号光与参考光干涉光强表达式。

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This required widening the antenna's beam to catch the probe in its uncertain orbit.

BBC: Signal picked up from Russia's stranded Mars probe