Background and Motivation
There are a number of GIS used in organisations to manage, maintain and distribute their data. Organisations maintain and provide specialised data according to their functions, however in many cases users or even organisations themselves need other datasets for a particular application. The data integration between different systems is not straightforward and time consuming . Likewise proprietary data formats are a major obstruction for data integration. Moreover, the addition and integration of data into existing databases poses many additional challenges.
The growth of Internet access and use coupled with advancements in web based technologies over the past decade has provided new possibilities for the access, delivery and use of GI . In recent years the GI sector has begun to recognise the importance and role of the web for the dissemination of spatial information, with many GI technology vendors now offering extended systems of Internet Map Server (IMS) to their desktop products e.g. ArcIMS, Geomedia, GE Smallworld IMS. The development of such systems has introduced and highlighted issues pertinent to the use of GI via the web. However, such systems still require data in their own proprietary formats. Proprietary IMS also typically disseminate these data in a proprietary format. In many cases we need to combine and distribute data from multiple heterogeneous systems. This requirement is hard to achieve using existing GIS.
Several organisations are now actively involved in addressing the problems of geospatial interoperability. The most prominent of these being 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) and web map services (e.g. Web Map Server (WMS), Web Feature Server (WFS)) 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.
Aims and objectives
The aim of this research is to use current interoperable standards among other common technologies to develop a solution for data interoperability and resolve the issues of proprietary systems and data integration from multiple heterogeneous data sources. The objectives can be given as follows.
- To investigate the current open standards, protocols and technologies capable of resolving the issue of data integration and dissemination.
- To investigate and test existing open geospatial web service e.g. Minnesota WMS.
- To use GML for vector online data format.
- To implement WFS for GML server to serve GML online.
- To design a common ad hoc database for data import/export in order to manage the data before dissemination
- To develop intelligent middleware capable to get the user requests for query vector/raster data from various different geospatial data web server, to retrieve the data as user requires, to combine those data together and finally to hand it back to the client user.
- To develop a web based GIS application that supports data request, retrieval, integration and presentation.