激光雷达微多普勒效应的仿真研究

Study on simulation of micro-Doppler effect in lidar

为了研究激光雷达中微多普勒效应的探测及其雷达回波信号中反应目标特征的微多普勒信息的提取问题,建立了激光雷达微多普勒效应的物理模型,对应用激光雷达探测由目标振动引起的微多普勒效应进行了仿真,并对仿真信号进行了分析,由于信号的时变性,引入了时-频域联合分析的方法。采用了短时傅里叶变换方法对仿真信号进行了时频分析,得到了能够较好地反映目标特征的微多普勒图像。结果表明,激光雷达适合于低振幅微多普勒效应的探测,应用时频分析方法能够有效地从雷达回波信号中提取出目标的微多普勒特征。

In order to study the questions of micro-Doppler effect detection in a laser radar and the extraction of micro- Doppler features indicating target characteristics from radar returned signal, a physical model for micro-Doppler effect in laser radar was built up, then the simulation of the micro-Doppler effect in the laser radar induced by vibration of the target was conducted. Because of the signal is time-varying,joint time-frequency analysis method was introduced. Short time Fourier transform was used to analyze the simulated signal in the time-frequency domain, a micro-Doppler image that can demonstrate the target characteristics was generated. Results show that a laser radar is fit for the detection of low amplitude micro-Doppler effect, and micro-Doppler features can be extracted from radar returned signal effectively by means of time-frequency analysis method.