这种方法克服了以往采用固定频率滤波器带来的相移和频率漂移问题，而且结构简单。

This approach the problem of conquers phase excursion and frequency drift that anciently adopts fixed frequency filter and its frame is simple.

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为了研究这一问题，我使用了一个滤波器组，来获得一系列固定在市电频率的信号。

To investigate this, I used a filter bank to obtain a set of signals locked to the incoming line frequency.

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在天气回波信号谱宽固定的情况下，通过改变天气回波信号的平均多普勒频率，分析了回归滤波器对它的衰减情况。

Fixing the spectrum width of the weather echo signals, we change theirs mean Doppler frequency and filter them using regression filter. After filtering, we analyze the attenuation of them.

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