Research On Incremental Updating Mechanism Of Urban 3D Spatial Database

The purpose of this paper is to solve the problem of integrated organization and updating of multi-source heterogeneous urban three-dimensional spatial data.Urban three-dimensional spatial data is an important part of the construction of new smart city.With the continuous development of Surveying and mapping technology and the increasing demand for 3D spatial data of the city,the acquisition means and the type of data products of the city's three-dimensional spatial data are increasing.With the continuous development of Surveying and mapping technology and the increasing demand for 3D spatial data of the city,the acquisition means and the type of data products of the city's 3D spatial data are increasing.Urban 3D spatial data are massive,multi-source and heterogeneous,and update speed is fast.Most of the traditional spatial database building programs are separately built and stored independently for multi-source heterogeneous spatial data,and it is unable to organize and update multi-source heterogeneous spatial data.Moreover,the organization and management of spatial data is seldom considered in the time dimension.In this paper,in view of the characteristics of urban three-dimensional spatial data and the existing problems of spatial database,a method of organizing and updating the three-dimensional spatial data of multi source heterogeneous cities based on datum grid model is proposed.This method is a kind of urban 3D spatial data organization model based on geo grid,which integrates modern surveying and mapping fast spatio-temporal data acquisition technology.It can effectively solve the technical problems of efficient organization,management and updating of multi-source heterogeneous urban three-dimensional spatial data.Based on the characteristics that the grid cell contains a series of high scene spatial data corresponding to the geographical area,the grid unit is used as the basic unit of spatial data organization and updating,so as to realize the unified organization and management of multi-dimensional heterogeneous urban3 D spatial data.At the same time,the geographic grid is used as the basic organizational unit of the incremental information and historical data,and the incremental information storage structure and the difference file of the urban 3D spatial data are studied and designed.According to the multi-source heterogeneous urban spatial data organization method proposed in this paper,three dimensional spatio-temporal spatial database and related table structure are designed.Based on this theory,this paper establishes a set of urban three-dimensional spatial data management platform.In the platform,the urban 3D spatial data is organized and managed in the form of grid unit,and store the incremental data and historical data of the urban 3D spatial data,and display the historical data through browser side,verify the feasibility of this data organization update method.The main contents of the research are asfollows:(1)This paper studies several updating methods of the current spatial database,and probes into the potential problems of spatial data,and analyzes the important role of the potential of spatial data in the practical application.On this basis,several typical spatio-temporal data models are studied and discussed,and the characteristics of different spatio-temporal data models are analyzed and summarized.Combining the characteristics of the city's three-dimensional spatial data and the potential requirements of the spatial database,choosing the appropriate spatio-temporal data model for the organization and construction of the incremental updating model of urban three-dimensional spatial data.(2)The design of urban 3D spatial data organization and updating method.We divide the urban geospatial space by geographic grid and set up the benchmark geo grid model.With geographic grid as the basic organizational unit,a unified organization of multi-source heterogeneous urban three-dimensional spatial data is carried out to realize integrated management of multi-source heterogeneous urban three-dimensional spatial data in the same organization framework.On this basis,we design the coding of grid units in the benchmark grid model.Through the grid coding,the multilevel three-dimensional spatial data association between different level grid units is established,and the spatial and temporal index of the urban 3D spatial data is designed to complete the design of the urban 3D data organization updating method.(3)The design of spatio-temporal city 3D spatial database.According to the organization method of urban 3D spatial data designed in this paper,the present situation database,historical database and caching database are set up,and the related table structure of the city3 D spatial database is designed.On this basis,using modified model based on multiple ground state multilevel difference files,and setting the ground state threshold in different periods,we set up many ground states in the database,and set up multi-level index for the difference files.With geographic grid as basic renewal unit,we organize and manage incremental information files and differential files to achieving incremental updating of urban3 D spatial data.(4)Based on the three-dimensional urban spatial database designed in this paper,three dimensional spatial data management platform is developed.The platform is used for incremental updating operation of urban 3D spatial data,which achieves functions of historical backtracking,GIS analysis and so on.Finally,it verifies the usability and effectiveness of the design method in this paper,and explores the role of incremental updating of urban 3D spatial data in practical application.