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facilitate access to geoinformation in such a heterogenous
environment, and to provide the mechanisms to ensure that
standards for data production and exchange are available
and maintained. The system should also support
integration, at different levels of decision making
(horizontally: across different thematic databases; vertically
from local to national levels), of distributed databases in a
federated system perspective. At the ITC, research in this
field focuses on the integration of institutional, technical and
economical aspects of geoinformatics, to realise the gradual
implementation of a Geoinformation Utility in different
countries. This integration is represented in Fig.2.
5. RESEARCH PROGRESSES
5.1 Definition of a planning and control framework
The development of an Information Utility in a well-
coordinated and integrated manner requires the setting of
a comprehensive and stable planning framework in time
perspective. The planning framework should seek to
translate the long-term Geoinformation Utility development
objectives into strategic specific courses of action in which
each step provides a tangible results that are relevant to the
needs and of a high priority. However, each step will also be
subject to the general policy direction that is required to
control the overall development process [S. Juma, 1994: A.
Bassolé, 1995].
The planning framework should define organizational
activities within the first stage of developing the
geoinformation infrastructure. It should set up the policy
framework and institutionalises the executive planning and
control. It further should spell out what activities should be
performed and what should be achieved in this specific
period of time. It should finally serve as a framework for the
preparation of detailed operational planning, execution and
control of the tasks to be carried out. The policy framework
should cover specific issues concerning the various types
of data to be collected, data communication and quality
standards, marketing, pricing and sales of products, and fee
Policies
Standards
Access/Use
Education
GES1 * Legislation
Standard * Integrity
Format
» GCS (general model)
* Information Directory
(Meta Data)
* Update Control
* Data Communication
DATA COMMUNICATION NETWORK
DB - Organisation's Database
LES- Local External Schema
SC -Sharable Components
GES- Global External Schema
GCS- Global Conceptual Schema
structure, data access, use and distribution. Other policy
matters include, data ownership, data integrity, security and
control.
A National Advisory Board is proposed to direct and control
the development process. Under this top level Committee
are the various task forces responsible for dealing with each
individual subject or groups thereof expressed in the policy
framework. These are Task Forces on standards, access
and use policy, organisation structure and changes,
marketing, costs and revenue structure, and on system
integrity.
5.2 Technical framework
5.2.1 A model for a Geoinformation Utility in a federated
perspective
The coordinated sharing and interchange of computerized
information can be controlled among autonomous
databases by a Federated Database System (FDBS) which
is a collection of independent and possibly heterogeneous
database systems united into a loosely coupled federation,
in order to share and exchange information. The basic
elements of the federated architecture are individual
components (geoinformation systems) that wish to share
and exchange information. A component may be viewed as
an autonomous database. The components must maintain
as much autonomy as possible; however, the components
must be able to achieve a reasonable degree of information
sharing. The model illustrated in Fig.3 is in principle
technology-independent. Each participants database
contains a specific land-related information plus other types
of information, useful for their specific applications; also
each database contains a land-related information which is
of interest for other participants and in some cases this
information is vital for their decision making process.
Furthermore, some applications on national level (global
applications) require integrated information from the
participating (different) databases [A. Al-Ansari, 1994], [M.
Radwan, Y. Bishr, 1995], [Y. Bishr, 1996].
DATA COMMUNICATION NETWORK
Figure 3: A proposal for a model of Information Utility
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International Archives of Photogrammetry and Remote Sensing. Vol. XXXI, Part B4. Vienna 1996
