Interoperability and the use of metadata
The Geographic Information Systems (GIS) community has over the years
captured and generated large amounts of geographic data, and developed
various geoprocessing capabilities. Discovery of these heterogeneous
georesources in federated GISs is the main concern in this research.
The sharing of these georesources involves locating, transforming, and
moving these georesources to end-users. At the moment users looking for
information has no alternative but to browse known locations and navigate
through links, hoping to find desired resources.
To address the interoperability of these georesources the Open Geographic
Information Systems (OpenGIS) Consortium was established. OpenGIS is the
transparent access to heterogeneous geodata and georesources in a
networked environment. This networked environment is characteristic of a
federation of GISs. A federated GIS is a collection of heterogeneous GIS
that collectively act as a single source of geographical information.
In this seminar is described an implementation of the Selector Broker,
component of a Georesource Centre, an infrastructure facilitating the
sharing of geographic data and geoservices among organizations. The role
of the Selector Broker is to process queries in search for appropriate
geodata sets from federated GISs.
Processing of queries within the Selector Broker involves translation
the metadata semantics and query syntax. In the design, organizations use
the Lightweight Directory Access Protocol (LDAP) to store descriptions
(metadata) of data sets they have collected. These descriptions are
processed by the Selector Broker to assist potential users to locate the
data sets they require.