Study On The Key Technology Of TLS Deformation Monitoring

In recent years,the terrestrial laser scanning technology is widely used in the field of deformation monitoring with its fast,high density and high precision.This technology makes the surveying and mapping convenient greatly,and puts its main work on the data processing at the same time.The key steps are registration,point cloud filtering,model building,multi-period model registration and deformation calculation.Among them,point cloud filtering and multi-period model registration problem has been the difficulty and hotspot of research.In this paper,the characteristics and classification of 3D laser scanning technology,the principle,data processing and application of terrestrial laser scanning technology are systematically introduced.On the basis of detailed introduction of the terrestrial laser scanning data filtering and DEM model registration,point cloud data filtering and uncontrolled DEM registration were studied.Firstly,a three-dimensional point cloud clustering filter algorithm for point cloud data processing is proposed based on the two-dimensional clustering algorithm,which avoids the loss of the spatial structure information of the point clouds,and makes full use of the high dimensions and high density characteristics of the TLS point clouds data.An experiment is carried out by comparing it with the curvilinear smoothing filtering algorithm and the moving least squares trend surface method,the experimental results show that the algorithm is effective in dealing with the cloudy data of dense terrain vegetation in the terrain.Secondly,for the problem of uncontrolled DEM registration,based on the existing ICP algorithm,LZD algorithm and LS3 D algorithm,the simulation data pairs of different terrain features are used to compare the registration performance of these three algorithms in the precision,efficiency and the scope of the registration,Which can provide reference for the uncontrolled DEM registration.Then,the terrestrial laser scanning data of Jiguanling Dangerous rock mass was processed by the above methods,and the deformation was calculated and analyzed in 10 months.