基矛电磁波的低流速测量中干扰因素分析研究

介绍了电磁渡测量流速的基本原理一多普勒效应．分析了影响低流速测量的主要干扰因素一发射泄漏干扰和旁瓣干扰。根据接收信号中发射泄漏干扰不变的特性，提出了去均值滤波的方法来消除干扰，对数据进行预处理；根据旁瓣干扰的信号特性，提出了通过频谱加窗和二次加权平均法构造频域带通滤波器来抑制干扰的方法，在仿真比较完各个窗函数的性能之后...

Research of interference factors on low water velocity measurement by electromagnetic wave

This paper described the electromagnetic wave measurement method in measuring water velocity based on Doppler effect at first. Then it pointed out that transmit leakage interference and side-lobe interference were the main interference factors of low velocity measurement. According to fixed characteristics of transmit leakage interference, mean filter method to eliminate the inference and to do data preprocessing were proposed. Due to the characteristics of side-lobe interference, interference through a band-pass filter which were structured by frequency-domain windowing and twice weighted average was suppete. After comparing the performance of each window function through simulation, we selected Blackman window was selected to do frequency-domain windowing. Simulation analysis showed that the side-lobe interference has been well suppressed by the frequency domain band-pass filtering method. Finally, significant effects of these methods were validated in low velocity measurement by experimental tests.