Web Services Composition and Geographic Information - Geographical Information Systems: Trends and Technologies - page 113

Abstract Description
Types
Message
Operation
Port Type
Concrete Description
Binding
Port
Service
Fig. 3. The structure of a WSDL Document.
promote the benefi ts of integrating location resources into commercial and
institutional processes and to facilitate the collaboration of developers and
users of spatial data products.
In the recent years, the broad consensus observed around the OGC
proposals has made services realized in OGC compliance the de facto
standard for the exchange of geospatial data in distributed environments.
In particular, the OGC services represent 'an evolutionary, standards-
based framework that enable seamless integration of a variety of online
geoprocessing and location services' (Doyle and Reed 2001). Moreover, by
using established technologies such as XML or HTTP, the OGC services
can provide a 'vendor-neutral, interoperable framework for web-based
discovery, access, integration, analysis, exploitation and visualization
of multiple online geodata sources, sensor-derived information, and
geoprocessing capabilities' (Doyle and Reed 2001).
Many factors have infl uenced the design of the OGC services; these
include, for example, the need to interconnect services often provided by
different organizations, the need to ensure requirements, such as access
control and security, and the necessity for a client to know what service
can be used with a specifi c type of data. However, although OGC services
use HTTP as the transport protocol and XML as the lingua franca for the
exchange of data, they are often incompatible with the platform proposed