The Fine 3D Modeling Of Buildings By Combining Airborne And Mobile LiDAR Data

The 3D modeling of urban buildings is a hotspot in the fields of Geographic Information Science,remote sensing and surveying and mapping.The 3D building model with high accuracy,high details and high integrity is widely used in the fields of Smart City,virtual reality and disaster emergency management,and it's economic and social values have become increasingly prominent.Both the airborne LiDAR and the mobile LiDAR are suitable for the rapid acquisition of 3D spatial information of large-scale urban buildings,which expressed building roof and facade separately.Due to the different ways of data acquisition,the airborne LiDAR can obtain relatively complete point cloud data of the building roof,but the facade information is missed,while the ground LiDAR can obtain rich facade data,but the roof point cloud obtaining ability is limited.If combine the two kinds of data sources together for 3D building modeling,the complete building geometry model can be obtained.Therefore,in order to meet the needs of fine building modeling,the method of 3D building modeling combining airborne and mobile LiDAR point cloud data is proposed in the paper.The main contents of the paper include five parts in the following:1 Summarized the research progress at home and abroad of building model reconstruction based on airborne LiDAR,ground LiDAR and the fusion data of the airborne and ground LiDAR.The disadvantages using airborne LiDAR data or mobile LiDAR data to construct the building model are analyzed.The advantages and research focus using fusion data of airborne and mobile LiDAR to construct the building model are also analyzed,which lays the foundation for constructing the complete 3D building model combining airborne and mobile LiDAR data.2 The principle of Li DAR technology and the composition of hardware equipments are analyzed,and the point cloud data preprocessing algorithm of point cloud data denoising,filtering,DTM building,etc.are studied.According to the characteristics of airborne and mobile LiDAR data,the related algorithms of point cloud data preprocessing are given in this paper.3 For modeling combining airborne and mobile LiDAR,the building roof modeling method using the airborne LiDAR data is studied,which mainly includes: building point cloud extraction and single building cluster and segmentation,the initial building outline extraction by using a modified local convex hull method,and the simplification and regularization of the initial outline.The RANSAC algorithm is used to segment the roof surface,and the topological relation analysis method is presented.4 The building facade modeling method combining the airborne and mobile LiDAR data is proposed,which includes: according to the characteristics of airborne and mobile LiDAR data,the registration method of the airborne and mobile LiDAR point cloud data combining coordinate transformation and ICP registration is used,building facade fine segmentation from the mobile LiDAR data by combining with the airborne LiDAR data.For building facade segmentation,the building facade points are segmented by combining building outlines extracted from airborne LiDAR data with the robust plane fitting algorithm.The method of using the mobile LiDAR data to build the facade outline model and detail model are studied.And the fusion method of roof model and facade is discussed.5 The experimental results show the effectiveness of the proposed algorithm.The modeling method using the airborne LiDAR data,the modeling method using the mobile LiDAR data and the fusion model in this paper are tested and analyzed.The results show that the proposed method can build a more complete and precise 3D building geometric model.