Study On The WebGIS Issuing System Of Railway Gongwu Based On Oracle Spatial Database

Presently, in some departments of the railway systems, the GIS meeting respective requirement are established to improve their managing level. However, these systems are not built based on the uniform criterion both in constructing method and technology standard, which leading to the information and resource of the railway departments not shared. In the Railway Geographic Information System (RGIS), the Distributed Database is utilized to uniformly store the information of basic geographic information, features, DEM and images concerning railway, and the network and communication technology are used to deal with the railway problems by means of digital methods and to share the information resources of railway.The spatial database and the WebGIS Issuing system are fundamental parts of the Railway Geographic Information System. The realization of the two parts is researched in the dissertation. The spatial database is the base of the RGIS, and especially the Object-Relational database, which supports integrating attribute data and spatial data, is the current mainstream. The storing format for spatial vector data is defined in the spatial module of Oracle database, and based on this a set of querying and index schema for vector data is offered. Furthermore, the storing and manipulating multi-media data (image, video and audio) schema is provided in the Intermedia module of Oracle database, so the non-structure railway spatial data can be stored in the two-dimensional tables and managed by the relational database management system. In the dissertation, the Dacheng Railway Gongwu spatial data of Maplnfo format are converted to the Oracle Spatial data format, stored in Oracle database, and then Dacheng Railway Gongwu-spatial database is built, then, using the Sichuan province relief map of raster format as an example, the method of storing image data in Oracle database isdiscussed.One of the main functions of the RGIS is to issue the railway information. It makes it convenient for users to access the relative information of railway. In the dissertation the technology of WebGIS and the component are analyzed, and then a testing WebGIS Issuing System for Dacheng Railway Facilities is established using browser/server network structure with spatial data of Dacheng Railway Facilities as an example. In the testing system, an issuing site is built using IIS, which is an Internet information issuing component developed by Microsoft Corporation. The MapXtreme, developed by Maplnfo Corporation, is used as map engine, which can implement various tasks such as map zoom, query analysis and layer control etc.