低盲区杂散光对激光雷达系统信号质量的影响

Influence of Stray Light in Low Blind Zone on Signal Quality of Lidar System

利用ZEMAX软件对透射式米散射激光雷达系统的杂散光进行分析,对激光雷达系统中光学镜片表面的反射和镜筒内壁系统的多次反射、散射进行模拟,得到镜面的多次反射光成像在探测器面源的功率可达3×10-8 W,镜筒散射光成像在探测器面源的功率达到2.8×10-9 W。在测量条件相同的情况下,通过对透射式和反射式激光雷达的连续观测结果进行分析,得出透射式米散射激光雷达的近场杂散光经过光电转换后的回波信号强度可以达到1000mV,比反射式激光雷达系统的高约17倍;用衰减片分别对两种雷达信号进行衰减处理,结果显示:当信号衰减80%时,透射式激光雷达系统的近场信号出现下翘现象。从对信号非线性化处理的结果也可以看出,反射式激光雷达系统优于透射式激光雷达系统。

Stray light of transmission type Mie scattering lidar system is analyzed by ZEMAX software,and the reflection of optical lens surface in the lidar system and multiple reflection and scattering of the tube wall system are simulated.The power of multiple reflection light imaging on the detector surface source reaches 3×10-8 W,and the power of lens barrel light scattering imaging on the detector surface source reaches 2.8×10-9 W.Under the same measurement conditions,we analyze the continuous observation results of two kinds of laser lidars,and conclude that the echo signal strength converted from near-field stray light in the transmission type Mie scattering lidar can reach 1000 mV,which is nearly 17 times that of the reflection type lidar system.Attenuation piece is used to attenuate the two lidar signals respectively.The results show that when the signal attenuation is 80%,the near field signal of the transmission type lidar system is turned up.It can be seen from the results of nonlinear signal processing that the reflection type lidar system is better than the transmission type lidar system.