A web-based spatial data access system using semantic R-trees

With the increasing use of geographical data in real-world applications, Geographic Information Systems (GISs) have recently emerged as a fruitful area for research. In order to provide information to a multitude of users, the World Wide Web (WWW) techniques have been integrated into GISs. A high-performance webbased GIS, called TerraFly, has been developed in order to provide web-based GIS accesses to the general public. The design of TerraFly considers two major aspects: (1) the system architecture including client, database server, proxy server and information server; and (2) the semantic R-tree data structure and semantic queries. The system architecture utilizes the existing resources to achieve maximum performance by using the “Internally Distributed Multithreading (IDMT)” technique. The spatial access method, semantic R-trees, is used to search for an object, based on both spatial and semantic information. System performance results are presented and analyzed. Reducing network traffic to achieve faster response to users is also discussed.