Research On Generation Method Of Electronic Sand Table Based On ArcGIS

Electronic sand table is a realistic three-dimensional terrain perspective, which is created automatically based on the geographic information data combining with the technology of modern computer graphics. Electronic sand table generates according to the composting theory of traditional sand table. Taking the place of the disadvantages of transitional sand table, such as long production cycle, much more occupation area, inconvenient to carry, the poverty of performance of contents, the high replacement cost and so on, electronic sand table is applied widely in those fields—urban construction, land planning, flood controlling, engineering construction, communicated network and city simulation.At present, the production of electronic sand table usually bases on 3D GIS platform, DEM data and texture image in the study area are integrated firstly, then other functions as observing, roaming and label are developed. But this method has some limitations for the research of a wide range of electronic sand table. Because large-scale roaming terrain is bound to require a higher computer platform, and the users have to wait a long time for the show of terrain landscapes, while the terrain display often relates to the complex technical strategy that how to control data in memory. The article discussed the process of producing electronic sand table which was the background to Shanxi Water Resources Information Management and Monitoring System. The paper described the methods of loading graph-based sites storage DEM and remote sensing images rapidly and dynamically in view of technology of GIS, RS, network and database. The 3D terrain scenes of a small area or a key water conservancy project can be simulated in real-time as research results.Electronic Sand Table—which is a sub-system of ShanXi Water Information Monitoring and Management System that is an important part of water information modernization in ShanXi Province. The background and significance of the research was introduced, and the frameworks of system architecture as well as all parts functions were designed according to user needs. The technologies of the producing the electronic sand table were discussed in details. Firstly, the system development environment was indicated:ArcGIS Engine components are used to support the 3D GIS functionalities in Visual Basic development environment. Secondly, based on the graph-based sites storage method of 1:10000 DEM and the resolution of 1 meter high-precision remote sensing images, this paper interpreted the pre-processing procedure of DEM and remote sensing images data before the formation of three-dimensional scene, as well as the method about how to use ModeBuilder in GeoProcessing module of ArcGIS to set up the model that can process spatial data automatically, and how to manage and storage spatial data under ArcSDE. Finally, the system described the implementation of each functional module, how to construct two-dimensional modules of electronic sand table and 3D GIS modules. The method of loading spatial data dynamically according to geographical coordinate for generation three-dimensional terrain scenes was emphasized in the fifth chapter. As a result of the generation of this 3D terrain, it is a complete electronic sand table together with viewer roaming and other functions in the 3D GIS module.Electronic sand table sub-system provides a variety ways from two-dimensional coordinates locating to three-dimensional targeting scene. The electronic sand table can represent simulated topography terrain in Shanxi Province, also provides a full range of technical services for the digital implementation and management of water projects.