SDI Convergence - Nederlandse Commissie voor Geodesie - KNAW

Services taking advantage of multiple data sets depend on the interoperability of the
information models underlying these data sets. Jantien Stoter, Wilko Quak and Arjen
Hofman explore in Harmonising and Integrating Two Domain Models Topography the
feasibility of harmonising and integrating two independently established information
models topography, expressed in UML (Unified Modelling Language) class diagrams.
They used two datasets representing topography at different scales for different purposes
in the Netherlands. For both datasets information models have been established
that describe the content and meaning of the data. Since the information models were
developed for different application domains they often do not align. The authors propose
an information model topography that integrates the two information models. In
this way they attempted to bridge the differences of two information models and arrive
at fluent data integration of similar data types available at different scales.
In An Analysis of Technology Choices for Data Grids in a Spatial Data Infrastructure,
Serena Coetzee and Judith Bishop address grid-enabling SDIs. A grid is a system integrating,
virtualising, and managing services and resources in a distributed, heterogeneous
environment. It supports virtual organisations across administrative and organisational
domains. A data grid is a special kind of grid in which data resources are
shared and coordinated. The authors present a scenario that describes how data grids
can be applied to enable the sharing of address data in an SDI. They developed Compartimos,
a reference model for an address data grid, and identified the essential components
for sharing address data on a data grid in an SDI environment. So far, data
grids have been applied to traditional data (text, image, sound). The authors now created
a bridge in the sense of applying relevant developments in non-spatial data to
spatial data. It is a promising way to manage the service-oriented SDI technically.
The importance of metadata documentation as a prerequisite for SDI is raised in SDI
and Metadata Entry and Updating Tools by Abbas Rajabifard, Mohsen Kalantari and
Andrew Binns. In this article, the authors assess metadata entry tools (METs) that
should allow for integrated management and updates of spatial data and its accompanying
metadata. This would prevent separated data collection processes, and two independent
data sets that must be managed and updated - spatial data and metadata.
The article highlights the significance of spatial data and metadata integration through
developing a set of criteria for metadata application development. These criteria are
used to assess a selection of METs.
One of these tools might have been the metadata tool developed and described in A
Prototype Metadata Tool for Land Use Change and Impact Models – a Case Study in
Regional Victoria, Australia by Stephen Williams, Christopher Pettit, David Hunter and
Don Cherry. They present a prototype tool for storing and managing model metadata. It
extends the utility of the more traditional model register allowing storage of details associated
with each instance of a model run. This Model Information Knowledge Environment
(MIKE) metadata tool shows promise in assisting the use of Natural Resource
Management models within Victoria, Australia and in providing details of modelling activities
throughout Victoria.
Practical issues that need to be overcome to successfully document metadata are discussed
in Implementation of Recent Metadata Directives and Guidelines in Public Administration:
the Experience of Sardinia Region by Luisa Manigas, Michele Beneventi,
Luca Corvetto, Rita Vinelli and Marco Melis. They provide insight in the process of implementing
metadata documentation. Metadata should take into account different
metadata requirements of applications. A general description in a national spatial data
register requires a limited number of metadata for each single datum, while at the re-
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