融合无人机机载激光雷达的变形监测技术研究

Research on deformation monitoring technology of integrated UAV airborne lidar

为提高变形监测精度,提出一种融合无人机机载激光雷达的变形监测方法。方法通过采用点云差值法(Point cloud difference,PCD)计算两期待监测区域的地表下沉数字表面模型(Digital Surface Model,DSM)差值,并基于无人机机载激光雷达数字正射影像图(Digital Ortho Map,DOM)计算地表水平移动矢量,分别实现了地表下沉监测和水平移动监测。仿真结果表明,所提方法可通过地表下沉监测和水平移动监测,有效、可靠地监测地表变形。在整个监测过程中,像控点精度对变形监测精度具有重要影响,随着像控点中误差的增加,下沉监测与水平移动监测误差增加,误差分布区间占比减小;当平面中误差和高程中误差均为6 cm时,下沉监测误差和水平移动监测误差分别为0.3 cm和0.2 cm,有效提高了变形监测精度,满足了变形监测误差需求,具有一定的实际应用价值。

In order to improve the accuracy of deformation monitoring,a deformation monitoring method based on UAV airborne laser radar is proposed.Methods By using the point cloud difference(PCD)method to calculate the difference of the digital surface model(DSM)of the surface subsidence in the two expected monitoring areas,and calculating the horizontal movement vector of the surface based on the digital Ortho Map(DOM)of the UAV airborne laser radar,the surface subsidence monitoring and horizontal movement monitoring were realized respectively.The simulation results show that the proposed method can effectively and reliably monitor surface deformation through surface subsidence monitoring and horizontal movement monitoring.In the whole monitoring process,the accuracy of image control points has an important impact on the accuracy of deformation monitoring.With the increase of the error of image control points,the error of subsidence monitoring and horizontal movement monitoring increases,and the proportion of error distribution range decreases;When the mean square error of the plane and the mean square error of the elevation are both 6 cm,the subsidence monitoring error and the horizontal movement monitoring error are 0.3 cm and 0.2 cm respectively,which effectively improves the deformation monitoring accuracy,meets the deformation monitoring error requirements,and has certain practical application value.