基于点云数据内插DEM的精度比较研究

Research on Precision Comparison of Interpolation DEM Based on the Point Cloud Data

利用3维激光扫描技术,以云南元谋干热河谷地区冲沟为研究对象,扫描获得大量具有冲沟坐标信息的点云数据。离散的点云数据之间没有明显的拓扑关系,不能表达连续的地表形态,通过建立格网DEM可视化表达地形信息,利用不同的内插方法生成DEM并进行精度评定,以便在不同的地貌区和采点方式下选用最佳的内插模型。点云数据经过数据配准拼接以及噪声剔除,在ArcGIS软件中,通过数据格式转换,利用反距离加权插值、克里金插值、自然领域法插值三种不同的内插方法生成DEM模型,通过检查点法分析已有的固定点高程和内插相应点的高程值做误差比较,分析不同的内插精度。实验表明,反距离加权插值法和克里金插值中误差基本相同,自然领域法插值中误差最大。分析比较不同的内插精度,对地表的坡度、坡向、等高线的研究具有重要的意义。

Taking DHV surface gully of yuanmou in Yunnan province as the research region,point cloud data with gully coordinate information is obtained based on 3D laser scanning technology.There is no obvious topological relationship between the discrete point cloud data and cannot express the continuous surface morphology,which can be expressed through the establishment of the grid DEM visualization terrain information by using different interpolation methods making DEM generation and accuracy assessment to select the best interpolation model under different terrain areas and sampling sites.After the data registration,joining and noise elimination and through data format conversion,DEM model is generated by the three different interpolation methods,which are Inverse Distance Weighted,Kriging interpolation and Natural area interpolation with ArcGIS software.With the method of Check points,the paper analyzes error comparison between the existing protection inspection elevation and the corresponding inserted point elevation value.Experimental results show the error of Inverse Distance Weighted and Kriging interpolation are basically the same,contrary to Natural area interpolation method.Analysis and comparison of different interpolation accuracy has important significance on the surface of slope,slope direction,and the contour.