Geographic Information System Interoperability in Local Community Environment

This is a problem of semantic heterogeneity and can lead to interpretation conflicts during interchanging of geo-data. These conflicts can be resolved only by human intervention. Such situation can be acceptable only in case of small amount of data. But in cases of large amount of data (thousands of records) this process can be very tedious and ineffective. This process can be automated only if problems of semantic heterogeneity and interpretation conflicts are solved.

Related work
Being seen to "be interoperable" is becoming increasingly important to a wide range of organizations, including central and local government. Interoperability is the ability of two or more systems or components to exchange information and to use the information that has been exchanged [7,8]. Interoperability of information systems relies on bases of agreement that describe what is shared among information sources. Interoperability means openness in the software industry, because open publication of internal data structures allows GIS users to build applications that integrate software components from different developers. Interoperability also means the ability to exchange data freely between systems, because each system would have knowledge of other systems’ formats [9].

The need to share geographic information is well documented [1,9,10]. Recent reviews of GIS interoperability and integration efforts can be found in [7,8]. Making local geographic datasets available publicly and establishing a common interoperability framework over shared data interchange protocols are important parts of this research.

Although distributed geo-libraries offer numerous advantages over stand-alone geographic databases, there are institutional and technical problems of geo-data sharing and interoperability. These problems have become, over the last several years, the focus of international research and infrastructure efforts and have been discussed at several international conferences and workshops focused on GIS interoperability [10].

One solution for data exchange between different GIS data sources would be a single architecture and set of standards for geospatial data. A broader discussion of geographic information exchange formats can be found in [11]. One of important strategies for interoperability is conversion of different data formats in common data structure. This kind of data structure is usually based on one of existing GIS standards. However, it's all but impossible to conceive that the global GIS community would adopt a single geospatial architecture or data standard worldwide. This means that standardization efforts alone won't produce interoperability.

In the past few years the OpenGIS Consortium [12] (OGC) has emerged as a major force in the trend to openness, as a consortium of GIS vendors, agencies, and academic institutions. The OGC introduced approaches for effective management of interoperability technology in cooperation with industry and universities. The OGC has identified the need for open geo-data sharing and the exchange of open GIS services.

Despite standardization initiatives, the use of standards as the only worthwhile effort to achieve interoperability is not widely accepted [13]. Since heterogeneity arises naturally from a free market of ideas and products there is no way for standards to banish heterogeneity by decree. As a consequence of two main system characteristic, distributed data sources and their heterogeneity, the realization of interoperability systems is weighty process.

Today, a number of proven and well established methods exist that allow heterogeneous databases to communicate on a technical level, including federated databases and schema integration, object-oriented approach and mediators and ontologies.

GeoNis Generalized Framework
GeoNis is a project that has to provide infrastructure, platform and software tools for data interchange in the local community environment. This project was developed with cooperation from Municipality of Nis and is partially founded by Ministry of Science, Technology and Development, Republic of Serbia.

The goals of research activities in GeoNis project are:

  • Defining interoperability architecture for integration of distributed and heterogeneous GIS data sources in local community environment
  • Defining a methodology and software support for resolving semantic conflicts in data from different information sources.
The goal of the GeoNis framework is to make the use of different data sources in their GIS applications simple for users. In order to achieve interoperability following six presumptions have to be fulfilled [14]:

  • Simple - users should not have to understand all details about the data or their source system to import and use them.
  • Transparent - complexities associated with data transfer should be hidden from users.
  • Open - interoperability should apply to all systems, and data exchange should be independent of the technology used.
  • Equal – systems are equal and autonomous.
  • Independence – systems have exclusive right to control its information and information processing without centralized control.
  • Effective - data transfer should be reliable, and the resultant data should be useful for the intended purposes.
  • Universal - all geospatial databases should be accessible.
  • Belonging – each system belongs to one GI community, and has its own institution, policy and culture and value viewpoint.
In local community data sources are services and offices that own geo-data in some format. Specified communities own GIS application, often created with different GIS tools and with different underlying database management systems. GeoNis project for interoperability in local community environment implies several different prerequisites:

  • Participants have knowledge of each other’s and data they possess.
  • Cooperation between participants.
  • Institutional willingness for realization of interoperability. All participants have to agree upon basic principles for realization of interoperability and to provide all needed data and resources.
  • Infrastructure for realization of interoperability: network infrastructure (hardware and software), people, organizations and activities, rules and regulations for information exchange.
  • Definition of communication protocols between participants
  • Development of software tools for realization of interoperability
  • Local information sources must be adapted in order to work properly in new environment.
GeoNis is generalized framework for interoperability of GIS applications that have to provide infrastructure for data interchange in the local community environment [1]. Data sources are local services and offices that own geo-data in some format.

Our framework for interoperability has to provide [14]:

  • Integration of information from different sources with ability to add new information sources.
  • Adaptation of existing data sources and queries without possibility for changing existing data.
  • Independence of user applications from information sources
  • Solving problems of semantic inconsistence between user requests and available data

Fig. 2. GeoNis framework for semantic interoperability




Page 2 of 3
Previous | Next