小波变换与匹配滤波耦合的激光雷达弱信号处理

Faint signal processing of lidar based on wavelet transform and matching filter

远距离激光雷达回波信号弱,干扰强,处理比较困难。距离越远,得到的有用信号就越弱。为了提高激光雷达检测距离,对弱信号进行数字信号处理就显得很重要。采用一般方法常将干扰信号判断成有用信号,从而影响了激光雷达的工作能力。本文采用小波变换和匹配滤波耦合的方法对激光雷达弱信号进行处理,既能从强噪声中提取有用信号,又能有效的去掉强干扰信号。采用一台TEA-CO2激光器进行实验,当采样速率达到200MHz时,对于信噪比大于1.2的含噪信号能有效地去掉噪声和强干扰信号,在保持原信号特征的情况下,准确地提取出有效的弱信号。这就有效地提高了激光雷达的工作能力。

In order to improve the power of detecting weak lidar signal, the key is digital signal processing of weak lidar signal, The common methods often verdicts interference signal as useful single so affect efficiency of laser lidar. In this paper, a method whieh composed of wavelet transform and matching filter was used to analyze those echo signals. Using a TEA CO2 DIAL lidar to make experience, when the sampling rate to 200MHz, for those signals with S/N above 1.2, the noise and powerftd interference signal can be eliminated, and effective faint signal can be picked up.This method can widely improve work ability of Lidar.