无人机激光雷达高程测量精度评定分析

Evaluation and analysis of UAV LiDAR height measurement accuracy

为了最大限度提升并量化测试无人机激光雷达系统对地表形变量的识别能力,通过系统探讨机载LiDAR技术的误差来源及其有效改进措施,借助5个红外测距仪器检测墩与5、10、30、50、70 mm 5个不同厚度板,使用相同无人机与激光扫描设备对观测墩在放置厚度板前、后重复扫描,将多期数据间作一阶差分处理,最大限度抵消机载LiDAR技术对地面高程扫描的系统误差,以测试目前市场主流机载LiDAR设备对小量形变的监测能力,获得了较为可靠的测试效果。结果表明:在多次重复形变监测中,无人机LiDAR点云扫描技术对地表z方向上形变量的最高识别能力约30 mm。基于该测试结果,无人机激光雷达扫描技术不仅可用于传统地形测绘,还能够用于山体滑坡、矿区地表形变监测、地质运动以及自然灾害跟踪等领域,为同等及以上地表垂直方向形变量级的监测方案与实施提供了参考。

In order to maximize and quantify the ability of UAV LiDAR system in identifying surface shape variables,the error sources of airborne LiDAR technology and effective improvement measures are systematically discussed.By 5 infrared distance measuring instruments detecting piers and 5 plates with different thicknesses(5,10,30,50 and 70 mm),and UAV and laser scanning equipment,the observation pier before and after placing the thickness plate is repeatedly scanned.The multi period data are processed by first-order difference processing,which can offset the systematic error of airborne LiDAR technology in ground elevation scanning to maximum extent.The monitoring ability of airborne LiDAR equipment is tested for small deformation in the current market,for a more reliable effect.The results show that in repeated deformation monitoring,the maximum recognition ability of UAV LiDAR point cloud scanning technology is about 30 mm.The UAV LiDAR scanning technology can not only be used for traditional topographic mapping,but also be used in landslide,mining area surface deformation monitoring,geological movement and natural disaster tracking and other research fields.It provides a reference for the monitoring scheme and implementation of above surface vertical deformation.