基于Chirp-z变换的电波流速仪的测量精度研究

Research on measuring accuracy of electromagnetic wave velocity based on Chirp-z

测速中对回波信号的处理大多采用FFT方法测频。为了提高测量精度,需要增加采样点数,这样使得运算量增大。提出了一种局部细化方法,通过FFT找出感兴趣的某一频率范围,再对该段进行Chirp-z变换,也就是说在不增加采样点数,运算量增加不大的前提下,提高测量精度。实验结果表明,这种细化方法能够有效提高测量精度。

FFT is usually used to processing echo signal in velocity measurement system. In order to improve the measuremen~ accuracy, the sample points should be increased, which caused the computation to increase. A method of refining the local spectrum is proposed. Finding our interesting frequency range, then, processing the spectrum in this range by using Chirp-z. In other words, under the situation of not creasing sample points and computation, this method can improve the measurement accuracy. Experimental results show that this method can effectively improve measurement accuracy.