附加直流的低信噪比雷达微振动信号提取

基于毫米波雷达的微振动测量是一种非接触式高精度测量手段，在桥梁健康监测领域发挥着重要作用。微振动信号提取通常对雷达回波信号进行差分干涉处理获取差分相位信息，然后对差分相位积分反演得到高精度的目标形变量。高背景噪声下，差分相位出现缠绕现象，造成反演的形变量产生跳变，破坏了振动信息，无法准确反映目标的形变量和振动频率等振动特征。为了解决这个问题，本文提出了基于附加直流的低信噪比雷达微振动信号提取方法，该方法利用附加直流约束相位缠绕，并推导了附加直流带来的形变量幅度值调制系数，在解决形变量跳变问题的同时准确反演振动信号形变量。最后仿真数据与毫米波雷达实测数据验证了本方法的有效性。

Low SNR Radar Micro-Vibration Signal Extraction with Additional DC

vibration measurement based on millimeter wave radar is a non-contact and high-precision measurement method, which plays an important role in the field of bridge health monitoring. Extraction of micro-vibration signal for radar usually obtains differential phase information by differential interference processing of radar echo signal. Then the high precision target deformation is obtained by integrating the difference phase. Under high background noise, the differential phase faces wrapping problem, which causes the jump of deformation and destroys the vibration information, and cannot accurately reflect the vibration characteristics of target such as deformation and vibration frequency. In order to solve this problem, this paper proposes a micro-vibration signal extraction method based on additional DC. This method uses additional DC constraint phase wrapping and derives the amplitude modulation coefficient of deformation caused by additional DC. The method can solve the problem of deformation jump and accurately invert the deformation of vibration signal. Finally, the simulation data and the real data of millimeter wave radar verify the effectiveness of the proposed method.