| With the rapid economic development and the continuous advancement of science and technology,the drone tilt photography technology has played an important role in the process of large-scale terrain data collection,which has greatly promoted the related research of 3D surveying and mapping.It has laid a solid foundation for the application and promotion of geographic information technology.However,whether it is tilt photography,laser scanning technology,depth sounder technology and other surveying and mapping methods,each has its own shortcomings that cannot be overcome.Therefore,it has become more urgent to carry out research on the combination of multiple surveying and mapping methods,make use of the advantages of their own technologies,complement each other’s deficiencies,and comprehensively construct three-dimensional real-world models in various directions,and then visualize and analyze the three-dimensional real-world models.This paper aims at the problem that a single data source is easy to cause voids and deformations.It combines the three surveying and mapping methods of tilt photogrammetry,ground laser scanning and depth sounder to give play to the advantages of their respective technologies,make up for the deficiencies of a single surveying and mapping method,and realize the integration of underwater and underwater The three-dimensional real scene modeling of the river course,but only the terrain surface information can be obtained,and the problem that the relevant structural information of the wading building cannot be accurately expressed,the BIM model technology is used to accurately model the wading building model,and the environmental information and building information are realized.The effective integration of the system,and through the Cesium platform to realize the viewing and information query of the three-dimensional real scene of the river.The research content of this thesis includs:(1)Multi-source data collection for river channels,UAV tilt photography,3D laser scanner for water data collection,and tilt image matching to generate dense water point clouds;Laser scan water data for related pre-processing to achieve the experimental needs Standard;RTK cooperates with the sounder to collect underwater terrain and uses four interpolation algorithms to compare experiments.The optimal algorithm Kriging method is selected for interpolation processing to generate underwater terrain data.(2)Point cloud registration of multi-source data.This paper studies the coarse and fine registration algorithms of point cloud data above and below the river,an ameliorative point cloud registration algorithm FPFH is proposed.The K-D tree is used to create a spatial index of point cloud data,which improves the registration efficiency of feature point pairs and achieves accurate and fast registration of water and underwater data.After comparative analysis with traditional algorithms,the advantages of multi-source data point cloud registration algorithm in accuracy and efficiency are demonstrated.After comparative analysis with traditional algorithms,the advantages of multi-source data point cloud registration algorithm in accuracy and efficiency are demonstrated.(3)3D real-world modeling of integrated water and underwater river channels.A part of the river in the Inner Mongolia section of the Yellow River is used as a research area.The integrated water and underwater river model is established by combining the acquired study area images and registered point cloud data,and the accuracy of the river model established by this method is in compliance with relevant specifications.standard.However,the river channel model can only obtain the terrain surface information,not the internal dimensions and structural relationships of the building.Therefore,BIM parametric modeling is performed on river-related buildings to unify environmental information and building information.(4)Integrate the real-water and underwater integrated river course model with the BIM model,and realize the three-dimensional scene display of the river through the Cesium platform.The river reality model and the BIM model are converted into a data format suitable for Cesium,and the three-dimensional model is sliced to realize the network.Browse the actual scene model and BIM model of Duanhe Channel,and show the basic functions. |
