微多普勒效应激光平衡外差探测特性研究

摘要

面向远距离微多普勒效应探测，建立了激光平衡外差探测输出信噪比的数学模型，并在此基础上仿真对比了平衡外差探测和一般相干探测的信噪比，分析出在合理设置探测器结构参数情况下，平衡外差探测方法在提高信噪比上有明显优势特性。经过实验验证分析，接收信号经时频分析后较一般相干探测可读性更强，减小了特征提取误差，适用于远距离微动探测。研究为目标微动的实际遥感探测提出了一种高效可行的接收方法。%Aiming at the detection of the micro-Doppler effect at far distance,the signal to noise ratio (SNR)mathe-matical models of balanced heterodyne detection for coherent lidar were established.Based on this model,the SNR of balanced and common heterodyne were compared,and balanced heterodyne has obvious advantages on improving SNR under suitable detector′s parameters.By means of experimental verifying and analyzing,the echo signal is more reada-ble after time-frequency analysis compared with common coherent detection,which decreases the error in feature ex-traction.This research presents an effective receiving method for practical micro-motion remote sensing.