Research And Implement On The Spatial Data Organization And Management Of 3D-WebGIS

With the development of network technology, computer graphics and computer technology, 3D-WebGIS which combines with the network technology and three-dimensional visualization technology becomes the development direction of GIS. The research of 3D-WebGIS focuses on three-dimensional visualization, three-dimensional spatial analysis, and multi-source data integration and so on. In addition to the three-dimensional visualization, the spatial data organization and management under the network environment also becomes a research hotspot.3D-WebGIS includes various types of massive spatial data, such as multi-source multi-resolution terrain data and image data, vector data, three-dimensional model data and so on. How to organize and manage these massive data effectively has become a bottleneck that restricts the development of 3D-WebGIS. According to the current research status, this paper has a systematic study on the spatial data organization and management of 3D-WebGIS.First, the article describes the spatial data types of 3D-WebGIS, and how to choose the spatial reference system. Then in order to solve the massive data's three-dimensional rendering problem, according to the linear quad tree LOD model, the research analyze how to organize the images data and terrain data, how to builds the tiles pyramid database,and introduce the organization of 3D model data and usage of progressive model. Particularly the article proposes a scheme which is about how to request the tiled and classified vector data, and this scheme improves the vector data's loading efficiency.Second, aiming at the management of massive spatial data, this article proposes a disk storage optimization scheme, and design a mixed-type data management mode and multi-level caching mechanism, these methods improve the response speed and reduce the disk IO. According to the web publishing of spatial data, the research through some methods like spatial data compression, network streaming progressive transmission, the cluster-based data services to improve the response efficiency of the three-dimensional data. The research also designs Restful three-dimensional geographic information services.Then the implementation and testing of the system modules which are related to data organization and management are discussed in this article, such as quickly setting up of the image and terrain pyramid tile database, the design of the spatial database, data loading, the implementation and testing of three-dimensional geographic information services and so on.Finally, according to the data organization and management scheme which is discussed in this article, the NewMap3DGlobe System has been developed and applied in the digital city geographic information public platform's construction. The result verifies the feasibility of the scheme. At last the article put forwards the future research work.