摘要
实施光子飞行时间测量法时,光子飞行时间测量值受激光回波信号能量的影响会出现测量反转误差,从而影响系统三维成像的精度。本文描述了一种光子计数三维成像激光雷达系统反转误差的校正方法及其实验。提出的反转误差校正方法包含先验模型标定和反转误差校正两个步骤。首先,通过标定法得到系统反转误差相对于激光脉冲响应率的函数关系,建立系统的反转误差预测函数。然后,由系统反转误差函数预测出原始三维图像的反转误差图像并实现原始三维图像的反转误差校正。实验搭建了光子计数三维成像激光雷达系统,采用盖格-雪崩光电二极管(Gm-APD)作为光子探测器,由高速扫描振镜二维扫描获取三维图像。通过时间相关记录仪获取光子到达时间分布,分别得到原始三维图像和激光脉冲响应率。在反转误差校正的测试实验中,系统的测量均方差由校正前的33.2mm提高至8.1mm。实验结果表明,该反转误差校正方法可以有效降低光子计数三维成像激光雷达的反转误差。
When photon time-of-flight measurement is used,the measurement accuracy will decrease due to the reversal error of time-of-flight measurement.In this paper,a method to correct the reversal error is described in detail.The correction method proposed here included two steps：prior modeling calibration and reversal error correction.Firstly,the function relationship between laser pulse response rate and reversal error was obtained by the calibration method and the reversal error prediction function was established.Then,the reversal error of an original 3D image was calculated by the reversal error prediction function and the 3D image was corrected.Finally,a photon counting 3D imaging lidar system was constructed,in which the Geiger mode Avalanche Photodiode（Gm-APD） was used as a photon detector and the high-speed galvanometer as a scanner.A Time Correlation Single Photon Counting （TCSPC） module was used to mark the arrival time of each photon event.The original 3D image and laser pulse response rate were acquired by the arrival time distribution of photon events.In performance evaluation test,the mean square error of ranging results is improved from 33.2 mm to 8.lmm after correction.The reversal error correction method proposed in this paper effectively reduces the reversal error caused by the energy fluctuation of laser echo pulse in the photon counting 3D imaging lidar.
出处
《光学精密工程》
EI
CAS
CSCD
北大核心
2013年第10期2488-2494,共7页
Optics and Precision Engineering
基金
微光夜视技术重点实验室开放基金资助项目(No.J20130501)
国家自然科学基金资助项目(No61101196
No.61271332)
中国博士后科学基金资助项目(No.2012M521085)
