After frequency selecting when white light walks through the F-P sensor which cavity modulated by temperature, wavelength demodulating is realized with a plane grating and CCD.

采用铜管和端面镀膜的光纤制作f - P传感器，白光光源经过腔长受温度调制的F - P传感器选频后，用平面光栅和线阵CCD实现光波波长的解调。

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Supposing the LFM signals had been sorted and selecting the instantaneous frequency as identification character, the closest method is used to distinguish the signals.

在对LF M信号实现分选的基础上，选取待识信号的瞬时频率作为识别特征，利用最近邻方法对信号进行识别。

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The distance between the acoustic-emission source and the receiving transducer, and the background noise level are primary factors in selecting a particular frequency band.

声发射源与接收讯号传感器间的距离以及环境噪声的电平是选择频带的主要依据。

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