激光雷达中含时截面引起的时差和成像失真研究

基于激光辐射理论,推导了单像素激光脉冲测距中与时间相关的激光反射横截面关系式. 在高斯基模强度分布、高斯时间分布及平面反射的近似条件下,研究了含时截面引起的反射脉冲形变及时间测量时差,给出了误差的解析解. 针对脉冲测距的激光成像雷达,对时差导致的图像失真,给出了相应的仿真结果. 结果表明,时差随激光脚印面积和反射倾角增加而增加,随激光脉宽的增加而减小,其带来的成像失真变现为图像形变和方向性差异两种典型现象. 

Study on Time Error and Anamorphosis of Imaging Ladar Induced by Time-Dependent Inverse Cross Sections

Based on the theory of laser radiation, the expression of time-dependent inverse cross sections of laser pulse in single pixel laser ranging was deduced. The pulse stretching of reflected laser and time error caused by time-dependent cross sections were analyzed under the condition of approximate hypotheses that the transverse intensity distribution of laser pulse was fundamental Gauss model and the pulse waveform reflected from a slope plane was with Gauss distribution. Furthermore, the simulation results of anamorphosis caused by time error were given. The analytical solution of time error and its tendency versus different parameters were given. Results indicated that the time error would go up with the increase of laser footprint size and slope angle, but go down with the increase of pulse width. The anamorphosis contains two types. One is shape change and the other is the discrepancy of directionality.