Dr.Sanphet Chunithipaisan,
Department of Survey Engineering,
Chulalongkorn University, Bangkok, Thailand.
Email: Csanphet@chula.ac.th
Mr.Phil James
School of Civil Engineering and Geosciences,
University of Newcastle upon Tyne,
Newcastle upon Tyne, UK.
Philip.James@ncl.ac.uk
Prof.David Parker
Department of Survey Engineering,
Chulalongkorn University, Bangkok, Thailand.
David.Parker@ncl.ac.uk
Abstract
This paper reports research that resolves the issue of data integration from multiple heterogeneous datasets for performing network analysis operations. The current geospatial standards, protocols and technologies are investigated and implemented through the research. The methodologies to solve the creation of network topology on-line for supporting network analysis are suggested and tested. A software system is created with a number of tools to support such system. A scenario of application is tested around the real world dataset of the train network in London (UK).
1. Introduction
Utility and infrastructure networks impact society globally and are managed in both the private and public sectors. A huge amount of money has been invested to improve and develop these networks and their supporting systems to help service customers and solve business problems. The use of GIS for utility and infrastructure network is well-known and widespread. It provides a variety of tools to assist in the management and manipulation of utility and infrastructure networks. GIS can also support specialist tools for the analysis of linear networks. The specialised tools to manage and build topology are required to maintain the data and analyse network. The network GIS applications that use such tools include asset management, site selection, risk analysis and shortest path.
Sharing data among departments and/or organisations can save a huge amount of money. The most successful companies in the utility and infrastructure business use GIS to integrate geospatial with other corporate data to take maximum advantage of its resources (ESRI, 2002). There is, however, often little collaboration between organisations despite similarities of interest. This is mainly because of issues of data sharing and interoperability. These issues have concerned the geospatial spatial (GI) community for many years. Several organisations have presented a number of standards and specifications that attempt to persuade users to implement their system using the same standards or specifications. One such organisation is the Open GIS Consortium (OGC) which has developed and put forward a number of specifications and standards, aimed at promoting data sharing and dissemination amongst the GI community. Increasingly OGC specifications are being adopted and implemented by GI technology vendors and users to provide solutions to the problems of web based GI dissemination. In particular; the Geographic Markup Language (GML) (OGC, 2003) and web map services (e.g. Web Map Server (WMS) (OGC, 2001), Web Feature Server (WFS) (OGC, 2002)) looks set to play an increasingly crucial role in the future distribution of GI and services. The basic operation of requesting and retrieving data are performed via Uniform Resource Locators (URLs) and uses the Common Gateway Interface (CGI) protocol to pass the request details.
This paper reports the development of an expert system that is capable of combining linear network datasets from different data sources and carrying out network analysis taking advantage of existing standards, protocols and technologies. This system involves many various implementations and technologies. This research uses the London train network (including rail, tube and tram) for a case study to test such a system.
2. The London train network
The London train network is one of the largest public city transportation networks in the world. There are about 1000km of track in the network and about 4 million journeys made every day (Transport, 2003a). It includes three modes of train-based system; rail, tram and tube (the name of the underground railway system). Table 1 shows the names of the network lines in each mode of transportation.
| Mode | Name |
| Rail | Dockland Light Railway, National Rail |
| Tram | Tramlink |
| Tube | Bakerloo, Central, Circle, District, East London, Hammersmith & City, Jubilee, Metropolitan, Northern, Piccadilly, Victoria, Waterloo |
Table 1. The network lines in London train network