三维激光扫描监测地表沉降精度研究

发布时间：2018-08-07 18:51

【摘要】：目前三维激光扫描的精度研究主要集中在仪器测角测距精度及建模模型本身精度等的研究,为获得三维激光扫描技术地表变形监测的实际精度,指导地表变形监测方案设计,本文选取了平坦的水泥地、基本平坦的草地、有一定坡度的草地和山坡4种不同地形的实验场地,应用三维激光扫描仪获取其地表点云数据,利用基于克里金法规则格网DEM模型建模,研究了点云密度、设站距离、噪声、地形复杂程度对地表建模后沉降精度的影响。论文的主要研究成果如下:(1)数据处理结果表明,点云密度对沉降精度的影响并不明显,设站距离是影响精度的主导因素;通过在原始点云数据中引入高程随机误差模拟噪声对沉降精度的影响,可用于指导选取合适的点云去噪方法;利用曲率定量分析了地形复杂程度对沉降精度的影响,可用于判断仪器是否满足监测精度要求。(2)结合矿区地表沉降监测精度及点云去噪要求,研究了各实验场地最大设站距离与点云密度之间的关系;分析出实测建模后沉降精度一般情况下能达到仪器高程理论精度,最优地表建模后沉降精度可达到亚毫米级。(3)综合本文研究成果,将噪声对沉降精度的影响控制在1mm之内,在判断出仪器能满足测量精度要求的前提下,根据最大设站距离与点云密度的关系选取合适的设站距离,适当减小扫描点云密度节省外业测量时间,可用于指导设计最经济的地表变形监测方案。
[Abstract]:At present, the research on the accuracy of 3D laser scanning is mainly focused on the precision of measuring angle and ranging of instruments and the precision of the modeling model itself. In order to obtain the actual accuracy of the 3D laser scanning technology for monitoring the surface deformation, the design of the monitoring scheme of the surface deformation is guided. In this paper, four kinds of experimental sites of different terrain, such as flat concrete land, basically flat grassland, grasslands with certain slope and hillside, are selected, and the surface point cloud data are obtained by using 3D laser scanner. The effects of point cloud density, station distance, noise and terrain complexity on the settlement accuracy after surface modeling were studied by using DEM model based on Kriging rule grid. The main research results are as follows: (1) the data processing results show that the point cloud density has no obvious effect on the settlement accuracy, and the station distance is the dominant factor; By introducing elevation random error into the original point cloud data to simulate the effect of noise on settlement accuracy, it can be used to guide the selection of appropriate point cloud denoising method, and quantitatively analyze the influence of terrain complexity on settlement accuracy by means of curvature quantitative analysis. It can be used to determine whether the instrument can meet the monitoring accuracy requirements. (2) the relationship between the maximum station distance and the point cloud density of each experimental site is studied in combination with the monitoring accuracy of ground subsidence and the point cloud denoising requirement. It is found that the precision of settlement after modeling can reach the theoretical precision of instrument elevation in general, and the precision of settlement after optimal surface modeling can reach sub-millimeter level. (3) based on the research results of this paper, the influence of noise on settlement accuracy is controlled within 1mm. On the premise of judging that the instrument can meet the requirement of measuring precision, according to the relationship between the maximum station distance and the point cloud density, the appropriate station setting distance is selected, and the scanning point cloud density is reduced appropriately to save the outfield measurement time. It can be used to guide the design of the most economical surface deformation monitoring program.
【学位授予单位】：中国矿业大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：P225.2;P642.26

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