The design of a Web-based distributed Geographic Information System.

摘要

This thesis presents the design of a new kind of Geographic Information System that is Web-based. Data can be stored on and retrieved through any World Wide Web server. Using standards such as HTTP as the transfer protocol and TIFF and DEM as the data formats, this system allows for easy access of distributed geographic data. In order to demonstrate the feasibility of such a Web-based distributed Geographic information System, a proof-of-concept prototype called GeoBrowser has been implemented using C++.; Several issues and techniques have to be considered before implementing such a system. This thesis provides a thorough discussion of these topics, such as standardization efforts, geocoding and georeferencing issues, and techniques with which current Web browsers can be extended in order to be used as the front-end to a distributed Web-based GIS. The design of the proposed Geographic Information System uses the results of this discussion.; The prototype together with the concepts outlined in this thesis form the basis for a new kind of viewing system that provides the user with a new way of working with geographic data. The focus lies on the immediate task at hand, the interaction with geographic data, instead of on technical issues. This results in a more productive and satisfying use of the system. The proposed system design could be further enhanced and used for developing a fully functional Geographic Information System that also provides capabilities for editing geographic information.