一种强杂波环境下雷达目标微振动信号提取方法

基于宽带雷达的微振动测量是典型非接触式振动测量手段之一，具有可穿透障碍物、全天候工作的优势，在公路/铁路桥梁安全性监测、生命体征测量、目标识别等多个领域发挥重要作用。典型的雷达测振模型基于回波相位调制模型，即目标回波的相位变化线性依赖于目标振动。当目标位于强杂波环境中时，目标微振动对回波相位的调制程度减弱，容易被系统相位噪声淹没，因而难以高精确提取。为解决这一问题，本文提出一种基于慢时间差分共轭相乘的目标微振动信号提取方法，首先对目标复高分辨一维像作慢时间差分；然后差分结果与当前时刻目标像共轭相乘，取其实部；最后对上一步结果作积分得到目标上的微振动信号。该方法适用于强静止杂波环境下无宏观运动目标上的微振动信号高精度提取。 

A Micro-Oscillation Signal Extraction Method for Radar Target

Micro-vibration measurement based on broadband radar is one of the typical non-contact vibration measurement methods. It has the advantage of working all-weather. It plays an important role in many fields such as safety monitoring of highway/railway bridges, vital signs measurement, target recognition and so on. The typical radar vibration measurement model is based on the phase derivation model, that is, the linear dependence of the phase change of the target echo and the target vibration. When the target is in a strong clutter environment, the target vibration modulation signal in the radar echo phase is weak and easily submerged by the phase noise of the system, so it is difficult to be extracted accurately. In order to solve this problem, a method of extracting weak target vibration based on slow time difference conjugate multiplication is proposed in this paper. Firstly, the target high resolution echo is slowly time-differentiated. Then, the difference result is multiplied by the target echo conjugate at the current time, and the real part is taken. Finally, the vibration signal on the target is obtained by integrating. This method is suitable for high precision micro-vibration extraction of targets without macro-motion.