在建立1550 nm激光相干雷达探测系统的基础上,对运动目标微多普勒效应的探测进行实验研究。利用小波多尺度分析将实验所得到的时域信号分解为不同尺度下的信号成分,对包含微多普勒特征的信号成分进行重构(逆小波变换),从而获取了目标的微多普勒特征。为了更好地分析目标运动特征和估计运动参数,使用短时时-频分析方法对获取的信号做了进一步的处理。实验结果分析表明,该系统可有效地探测运动目标的微多普勒信息,且多尺度分析方法和短时时-频分析方法的联合应用可有效地提取运动目标的微振动信息。

A system of detecting micro-Doppler effect based on laser coherent radar worked in the 1550 nm wavelength is presented,and experimental research on micro-Doppler effect of detecting the dynamic target is developed. The time domain signal of the returns is decomposed into a set of components that are represented by different wavelet scales. The micro-Doppler features are extracted by sorting the components that are associated with the vibrational/rotational motions of a target and reconstructed by inverse wavelet transform. After the extraction of micro-Doppler features,time-frequency analysis is employed to analyze the oscillation and to estimate the motion parameters. The analysis of experiment results show that micro-Doppler information of the dynamic target can be detected effectively by this system,and tiny vibration can be acquired effectively by analysis of multi-resolution analysis and time-frequency analysis of short-time.