Highway Gis Application Of Component-based Technology

Geographical Information System (GIS) is a new brink subject, which integrates computer science, information science, mathematics, statistics, spatial science, remote sensing science, telemetry science, environmental science, manage science and so forth. It is an extension of Geographical Information System application to use it to process and update the data information of freeway. At the beginning of this thesis, the history of Geographical Information System development internationally is reviewed. Then the characters of Geographical Information System about highway in our country are contrasted and analyzed. Finally the problems to be urgently resolved are discussed. After analyzing the information mentioned above synthetically, the thesis establishes the research direction and working emphasis:1. After contracting the latest development trends of Geographical Information System and its several remarkable hotspots, MapX is the best choice for the basic development platform of the system.2. The technology foundation and characters of ComGIS are particularly expatiated. Obviously, ComGIS is one of development directions of GIS in the future. MapX, which is the more popular component, is selected for the platform of the system. The thesis also includes its structure and functional features as well as its application in the project.3. By contracting several databases, SQL Server 2000 is selected for the property database platform. Then the structure and function of SQL Server 2000 are anatomized in the thesis. Finally the structure of the route codes and the meaning of each data code are analyzed.4. The key in designing the property database is to preserve the course codes, which are main keys in the old investigating database of highway as the third sorted fields -the county and city, and besides, the city fields and the route codes are inserted as the second and the first sorted fields in each table of the database respectively.5. The common map is scanned into grid map, and then vectored in mapinfo. After vectoring, vector data are matched and the spatial coordinate data of resident points, water system and other data are gained. The coordinate of reference points in the freeway are gathered by GPS, then after data processing, coordinate transition, data inputting, it turn into the freeway graph, which composes the freeway electronic map with the materials subsidiary to the freeway.6. The popular Component Object Model-MapX based on the ActiveX is embedded into the Integrated Development Environment of Delphi 6.0. The electronic map of freeway of Henan province is inputted into the "Geoset" and then a series of function modules are developed. Finally the desktop GIS is finished.7. The Web product of the Mapinfo Company is used to publish the geographical information of Henan province freeway on the web, which lies in the server to realize the share of all information. The consumers only use their own browsers, obtaining all kinds of individuation geographical information server from the web. In the end, the disadvantages and the direction to improve of the system are alsomentioned.