Research On 3D Reality Reconstruction And Application Based On Multi-Sources Image Data Fusion

With the rapid development of China's economic construction and the increasingly acceleration of urbanization process,many fields are developing towards digitalization and intellectualization.The demand for spatial information data has gradually changed from traditional two-dimensional(2D)to three-dimensional(3D).Especially in 3D reality model,the demand has reached an unprecedented height.How to quickly,accurately and efficiently acquire 3D data,construct 3D reality model,and reduce production cycle and cost is the key problem in this field.Thus,recent years many modeling technologies have emerged,such as unmanned aerial vehicle(UAV)Oblique Photogrammetry technology,ground close scene photography,airborne LiDAR and terrestrial 3D laser scanning.However,from many studies,we can see that each technology has its own limitations.Therefore,it is of great theoretical and practical value to carry out multi-source data fusion technology research,give full play to their respective technological advantages,make up for defects,and realize the construction of a three-dimensional reality model with no dead angle.In this paper,two main 3D reality modeling technologies,i.e.UAV Oblique Photogrammetry and terrestrial 3D laser scanning,are taken as the research objects.Based on the research and analysis of their respective technical characteristics and defects,the feasibility of multi-sources data fusion modeling and the application of 3D reality model are emphatically studied.The main research contents are as follows:(1)It is discussed about construction of 3D reality model based on unmanned aerial vehicle(UAV)Oblique Photogrammetry technology and the layout schemes for control point in small area.By comparing and analyzing the accuracy of the 3D model constructed through different schemes,the one which conforms to small area will be summarized.Meanwhile,the 3D modeling technology based on Oblique Photogrammetry is analyzed according to the results of the 3D model.And the advantages and disadvantages of the techno logy in model building will also be clarified.(2)The terrestrial 3D laser scanning technology is deeply studied together with exploring the principle,characteristics,system classification and error causes of the technology.The process of acquiring and processing laser point cloud data is elaborated,and the splicing accuracy of the complete point cloud model is verified.Through the study of the whole process of 3D laser scanning technology,the characteristics and limitations of laser scanning modeling technology are further understood.(3)By deeply understanding the advantages and disadvantages of single technology such as UAV Oblique Photogrammetry technology and terrestrial 3D laser scanning technology for building 3D model,this paper proposes to integrate various technical approaches to realize the construction of 3D reality model,in orderto remedy the problems of model distortion,cavity and adhesion with single modeling technology.(4)GNSS precise positioning technology is applied for the construction of 3D reality model.The results are incorporated into the real national and urban coordinate frame for subsequent related applications.(5)With its characteristics e.g.,authenticity and real-time,the 3D model has been widely used in many fields,such as the construction of smart cities,urban planning,deformation monitoring,emergency rescue,smart tourism,confirmation of land right,etc.And the application process of the 3D reality model is elaborated through some engineering examples.