Research On Construction Technology And Method Of Landform Point Cloud Surface With Different Terrain Complexity

As an emerging surveying and mapping technology,ground 3D laser scanning technology is another technological revolution after GPS technology in the surveying and mapping field.This technology can construct detailed 3D models of target objects in a short period of time.With the rapid development of terrestrial 3D laser scanning system hardware and software,this technology is widely used in deformation monitoring,smart city construction,cultural heritage protection,topographic mapping,disaster assessment and other fields.With the rapid development of today's society,the demand for 3D models is increasing.The construction of 3D models based on ground3 D laser point cloud data has become one of the hot issues in the field of point cloud data processing research.Surface reconstruction technology is the key to constructing3 D models.It is also a hot research topic in recent years.Surface reconstruction from scattered and complex point cloud data is a difficult point in the problem of surface reconstruction.For different terrain complexity and topographic point clouds,in order to use the point cloud data reasonably and fully,and construct a surface with better accuracy and quality,this article is carried out.Study the following aspects and draw relevant conclusions:(1)Two kinds of surface construction methods based on grid and cross-section technology are adopted,which are realized by two common point cloud data processing software,Geomagic Studio and Imageware,respectively.Three groups of point clouds with different resolutions in the same area are studied and analyzed for surface construction.,It is concluded that the surface is constructed by Geomagic Studio software and the appropriate parameters are selected.The higher the resolution of the point cloud data,the higher the accuracy of the surface;the higher the quality of the point cloud data is required by the Imageware software.And the high-resolution point cloud contains a lot of noise points.Contrary to the Geomagic Studio software,if you select the appropriate parameters,the higher the resolution of the point cloud data,the lower the accuracy of the constructed surface.Comparing the surfaces constructed by the two softwares,the quality of the surfaces constructed by Geomagic Studio software is better,and the continuity and smoothness of the surfaces are better.For surface construction of such point cloud data,Geomagic Studio software and its faceting method are more suitable.(2)By calculating the main curvature of the point cloud data as an index to measure the complexity of the terrain,selecting low-resolution point clouds based on low terrain complexity and high-resolution point clouds for high terrain complexity,distinguishing three different groups of the same area The point cloud is segmented at a high rate,and the segmented point cloud is spliced to construct a complete surface,and compared with the surface constructed by three complete sets of point clouds with different resolutions,it is concluded that this method is a feasible and effective surface construction method.The surface constructed by this method has higher accuracy than the surface constructed by the low-resolution point cloud,and it takes less time than the surface constructed by the high-resolution point cloud.(3)The point cloud data is divided into blocks according to the terrain characteristics of the measured object.The method of constructing a surface based on the grid extraction feature is first used to construct the surface of the block point cloud,and then the block surface is completely spliced and combined with the unblocked point cloud Comparing the constructed surface,it is concluded that the surface construction method can effectively improve the surface accuracy and better express the terrain characteristics of the measured object.