针对强背景光下,Mie散射激光雷达回波信号所含噪声的特点,提出小波滤波消噪方法.该方法通过小波变换分离出背景光的直流部分,并利用小波软阈值消除来自背景光的白噪声和探测系统的电噪声.为了验证该方法的有效性,提取并反演了Mie散射激光雷达系统实际探测得到的大气回波信号.反演结果显示有效探测距离从2.5km提高到5km,表明该方法能够在白天背景下有效降低Mie散射激光雷达回波信号中的电噪声和背景光的噪声污染.
According to the characteristics of Mie scattering lidar echo signal contaminated by noise in day background light, a de-noising method of wavelets was presented. The daylight direct current component was removed by wavelet transform, and the white noise from background light and electrical noise from detection system were reduced by wavelets soft threshold. To verify the feasibility of the de-noising method, Mie scattering atmospheric lidar echo signal was actually extracted and retrieved, the test results show that the effective detection range can be improved from 2.5 km to 5 km, and the contamination from electric noise and the background light noise can be reduced by the proposed method in measurement of experimentations.