CEN/TR 15449:2006

SLOVENSKI STANDARD
01-november-2006
*HRJUDIVNHLQIRUPDFLMH±6WDQGDUGLVSHFLILNDFLMHWHKQLþQDSRURþLODLQYRGLOD
SRWUHEQD]DLPSOHPHQWDFLMRLQIUDVWUXNWXUH]DSURVWRUVNHSRGDWNH
Geographic information - Standards, specifications, technical reports and guidelines,
required to implement Spatial Data Infrastructure
Geoinformation - Normen, Spezifikationen, technische Berichte und Leitfäden zur
Einführung von Geodateninfrastrukturen
Information géographique - Normes, spécifications, rapports techniques et lignes
directrices, nécessaires a la mise en oeuvre d'une infrastructure d'information spatiale
Ta slovenski standard je istoveten z: CEN/TR 15449:2006
ICS:
07.040
35.240.70
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

TECHNICAL REPORT
CEN/TR 15449
RAPPORT TECHNIQUE
TECHNISCHER BERICHT
August 2006
ICS 07.040; 35.240.70
English Version
Geographic information - Standards, specifications, technical
reports and guidelines, required to implement Spatial Data
Infrastructure
Information géographique - Normes, spécifications, Geoinformation - Normen, Spezifikationen, technische
rapports techniques et lignes directrices, nécessaires à la Berichte und Leitfäden zur Einführung von
mise en oeuvre d'une infrastructure d'information spatiale Geodateninfrastrukturen
This Technical Report was approved by CEN on 24 June 2006. It has been drawn up by the Technical Committee CEN/TC 287.
CEN members are the national standards bodies of Austria, Belgium, Cyprus, Czech Republic, Denmark, Estonia, Finland, France,
Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania,
Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION
EUROPÄISCHES KOMITEE FÜR NORMUNG
Management Centre: rue de Stassart, 36  B-1050 Brussels
© 2006 CEN All rights of exploitation in any form and by any means reserved Ref. No. CEN/TR 15449:2006: E
worldwide for CEN national Members.

Contents Page
FOREWORD . 4
INTRODUCTION . 5
1 SCOPE. 9
2 CONSIDERED STANDARDISATION INITIATIVES.9
3 TERMS AND DEFINITIONS . 10
4 ABBREVIATED TERMS. 11
5 SPATIAL DATA INFRASTRUCTURE AS AN IMPLEMENTATION-NEUTRAL FRAMEWORK . 13
5.1 MANAGEMENT SUMMARY . 13
5.2 STANDARDS AND INTEROPERABILITY. 13
5.3 GENERIC ARCHITECTURE MODEL. 14
5.4 DATA-CENTRIC VS SERVICE-CENTRIC . 15
5.5 SDI AS A DYNAMIC FRAMEWORK . 15
6 DATA-CENTRIC VIEW ON SDI. 16
6.1 MANAGEMENT SUMMARY . 16
6.2 DEVELOPMENT. 17
6.2.1 The model-driven approach. 17
6.2.2 Semantics. 18
6.2.3 Application schema. 18
6.2.4 Conceptual schema language . 19
6.2.5 Encoding. 20
6.2.6 Relevant standards. 20
6.3 DATA MANAGEMENT. 21
6.3.1 Metadata. 21
6.3.2 Accessing data . 22
6.3.3 Legacy datasets. 22
6.3.4 Consistent identification of geographical items. 22
6.3.5 Thematic identifiers . 24
7 SERVICE-CENTRIC VIEW ON SDI . 24
7.1 MANAGEMENT SUMMARY . 24
7.2 REGISTRIES AS THE SDI GLUE . 24
7.3 PUBLISH, FIND AND USE RESOURCES. 25
7.3.1 General . 25
7.3.2 Publishing geo-resources . 26
7.3.3 Finding geo-resources . 26
7.3.4 Using geo-resources . 26
7.4 INTEROPERABILITY. 26
7.4.1 General . 26
7.4.2 Explaining the concept. 27
7.4.3 Different types of interoperability. 27
7.5 SERVICE TAXONOMY . 27
7.6 SERVICE ARCHITECTURE . 28
7.6.1 Introduction . 28
7.6.2 Web services . 28
7.6.3 Services that do not apply Web Service Architecture . 29
7.6.4 When to apply WSA . 29
7.6.5 Other technologies. 30
7.6.6 UDDI or ebXML?.30
7.7 SERVICE CATALOGUE.30
7.8 SERVICE CHAINING .31
8 REFERENCE MODEL FOR A SDI .32
8.1 INTRODUCTION .32
8.2 VIEWPOINTS AND LEVELS OF ABSTRACTIONS.33
8.3 FRAMEWORK STANDARDS.36
8.3.1 General.36
8.3.2 Other geoprocessing services.36
8.4 SPATIAL DATA .36
8.4.1 General.36
8.4.2 Features.37
8.4.3 Coverages.40
8.5 METADATA AND CATALOGUE SERVICES .42
8.5.1 Overview .42
8.5.2 Abstract models.43
8.5.3 Implementation Specifications .44
8.5.4 Service metadata and registries .44
8.6 PORTRAYAL SERVICES .44
8.6.1 Overview .44
8.6.2 Abstract models.45
8.6.3 Implementation Specifications .45
8.7 GEOSPATIAL REFERENCE SYSTEMS .46
8.7.1 General.46
8.7.2 Abstract models.46
8.7.3 Implementation specifications.47
8.7.4 Related services.48
9 MULTI-LINGUAL AND CULTURAL ADAPTABILITY.49
9.1 INTRODUCTION .49
9.2 MULTILINGUAL RESOURCE DISCOVERY .51
9.3 MULTILINGUAL EVALUATION OF RESOURCES .52
9.4 MULTILINGUAL ACCESS AND PROCESSING OF RESOURCES.52
9.5 CULTURAL AND LINGUISTIC ADAPTABILITY IN THE COMMON UNDERSTANDING OF STANDARDS.53
10 GEO-PORTALS.53
11 IMPLEMENTATION STEERING MECHANISMS .55
11.1 IMPLEMENTATION PLAN.55
11.2 MONITORING .55
11.3 CONFORMANCE AND CONFORMANCE TESTING.56
11.3.1 General.56
11.3.2 EN ISO 19105 .56
11.3.3 Open Geospatial Consortium.57
11.3.4 Requirements for conformance testing.57
12 REQUIREMENTS NOT CURRENTLY COVERED SUFFICIENTLY BY GI STANDARDS .58
ANNEX A DESCRIPTION OF REFERENCED ISO STANDARDS, EN ISO STANDARDS, ISO PROJECTS
AND OGC SPECIFICATIONS .60
ANNEX B CROSS-REFERENCE OF CEN/TC 287 AND ISO/TC 211 STANDARDS AND REPORTS TO SDI
TOPICS.75
ANNEX C OPEN GEOSPATIAL CONSORTIUM.79
BIBLIOGRAPHY .81

Foreword
This Technical Report (CEN/TR 15449:2006) has been prepared by Technical Committee CEN/TC 287
“Geographic information”, the secretariat of which is held by NEN.

Introduction
Spatial Data Infrastructures (SDIs)
The proposal of the European Commission for a Directive establishing a spatial data infrastructure for Europe
(INSPIRE) (European Commission 2004) defines a SDI as the metadata, spatial data sets and spatial data
services; network services and technologies; agreements on sharing, access and use; and coordination and
monitoring mechanisms, processes and procedures, established, operated or made available in an
interoperable manner.
This Technical Report focuses on the technical aspects of a SDI, thereby limiting the term SDI to mean a
platform- and implementation-neutral technological infrastructure for geospatial data and services, based upon
standards and specifications. This report does not consider a SDI as a carefully designed and dedicated
information system; rather, it is viewed as a collaborative framework of disparate information systems that
contain resources that stakeholders desire to share. The common denominator of SDI resources, which can
be data or services, is their spatial nature. It is understood that the framework is in constant evolution, and that
therefore the requirements for standards and specifications supporting SDI implementations evolve.
Intended readership
The intended readership of this report are those people who are responsible for creating frameworks for SDI,
experts contributing to INSPIRE, experts in information and communication technologies and e-government
that have to familiarize themselves with geographic information and SDI concepts, and standards developers
and writers.
Aim of the report
The aims of this report are three-fold:
 to identify the standards, specifications, technical reports and guidelines, required to implement a SDI in
Europe;
 to give recommendations as to whether any of these items should become EN, and to propose a
roadmap for future work items;
 to provide recommendations for measures to be taken in order to support implementation and
maintenance of a SDI.
Structure of the report
Existing material about SDIs abounds. This report structures and refers to this existing material. The criteria
used for determining if a given standard or specification is referred to in this report are:
• the publication is non- proprietary of nature, and
• the publication addresses an aspect of the SDI.
Based on the above considerations, and based on discussion within CEN/TC 287 Working Group SDI, the
following reports have been taken into account:
 documents produced by ISO/TC 211 (ISO/TC 211, 2005);
 documents produced by the Open Geospatial Consortium (OGC), including the OpenGIS Reference
Model (ORM) (OGC, 2003);
 INSPIRE Architecture and Standards Position Paper (Smits, 2002);
 Geospatial Interoperability Reference Model (GIRM) (Evans, 2003);
 internal report of CEN/TC 287/WG5 Spatial Data Infrastructure on the use of standards in SDI projects
(August 2004);
 existing national guidelines based on the (EN) ISO 19100 series of standards.
Clauses 1 to 5 are introductory of nature, with the first four focusing on the scope, the considered
standardization initiatives, the terms and definitions, and the symbols and abbreviated terms, respectively.
Clause 5 explains what a SDI is.
The subsequent clauses cover the main concerns of a SDI in Europe. Clauses 6 and 7 give a data-centric and
a service-centric view on SDI. The data- and service-centric views are brought together in the Reference
Model for a SDI (Clause 8). Clause 9 addresses concerns related to multi-lingual and cultural adaptability,
followed by a clause dedicated to geo-portals (Clause 10). Clause 11 provides considerations that are
relevant for the implementation of SDI. Clause 12 identifies SDI aspects currently not covered by standards.
Management summary
In order for standards and specifications to be useful for implementing a SDI in Europe, it needs to be
straightforward to identify which standards are relevant in a particular situation, and the interpretation of
standards should be unambiguous. This Technical Report provides a framework for the identification of
standards, and gives a number of recommendations with the aim to enhance interoperability between
information systems that provide data and services in support of a SDI. The following paragraphs summarize
the recommendations of this Technical Report.
Recommended standards and documents
Standards and documents that are recommended for use within SDIs in Europe appear underlined in the
Reference Model (Clause 8). Standards that are not underlined are standards that are used or could be very
useful in some communities, but are not considered as a main component in a European SDI.
This Technical Report encourages the geographic information software industry to support standards for the
creation and management of geographic information and to implement appropriate interface specifications in
their products. At the same token, it is recommended that relevant standards be used in public procurement,
and that any findings related to the implementation of standards are fed back to the relevant standardization
bodies.
Registries
For the realisation of SDI in Europe, it is recommended to establish one or more registration authorities.
A SDI needs, like any other distributed information system, a reference frame. A reference frame is the
aggregation of the data needed by different components of the information systems. In a SDI context, the
reference frame concerns:
 the units of measures;
 the coordinate reference systems;
 the codelist definitions;
 the feature data dictionaries (see ISO 19126);
 the feature catalogues (see ISO 19110);
 the portrayal catalogues and related symbology registers.
It is recommended that registries are established for the above-listed information elements and geographical
items, and for:
 cultural and linguistic adaptability of metadata elements;
 European common data models;
 national data which are of interest in a cross border community or in a multilingual community.
Appropriate standards for registries for information elements and geographical items would need to be
identified or developed. Registries should be conformant to ISO 19135, Geographic information — Procedures
for registration of geographic information items.
In order to enable the cultural and linguistic adaptability (CLA) of metadata and common data models, it is
recommended to use unique names and codes for the information elements and the geographical items (e.g.
feature type). A number of practical suggestions related to CLA are given in Clause 9.
Data
 The model-driven approach is promoted for ESDI.
 Unique identifiers for use in a European SDI should be composed of a namespace and a Universally
Unique Identifier (UUID).
 ISO 19109 and referred standards are promoted as ESDI rules for specifying data structures and
semantics.
 UML class diagrams used according to ISO/TS 19103 is promoted as an ESDI conceptual schema
language.
 ISO 19136 (GML) is promoted as the ESDI encoding method when transferring geographic data.
 ISO 19139 is promoted as the ESDI encoding method when transferring information related to geographic
data such as metadata, feature catalogues, data dictionaries, …
Services
This Technical Report recommends that all services be categorized according to the ISO 19119 taxonomy.
This Technical Report recommends applying the Web Service Architecture (WSA), including WSDL, SOAP,
UDDI and XML when the following issues are considered to be important:
 components of information systems run on different platforms;
 the system consists of components from different vendors;
 the service is to be published and available on the internet;
 wrapping of existing services where these are exposed as web services;
 make existing services available for other applications on other platforms.
It is inappropriate to apply WSA when transferring large datasets.
Conceptual Schema Languages
This Technical Report encourages the use of UML.
If an information community applies a Conceptual Schema Language other than UML, it is the responsibility of
that information community to map the ISO general feature model to the meta-model of the Conceptual
Schema Language of choice, and to maintain the mapping rules, following the ISO/TS 19103 conformance
statement:
Non-UML schemas shall be considered conformant if there is a well-defined mapping from a model in the
source language into an equivalent model in UML and that this model in UML is conformant.
In order to provide a GML application schema, an application schema should be made by applying a
conceptual schema language, and the GML application schema should be derived from that conceptual model,
applying the rules for mapping from UML as described in Annex E of ISO 19136.
Conformance testing
It is recommended to establish a conformance authority charged with the conformance testing of
implementations of SDI elements in Europe.
Roadmap for new work
It is recommended that CEN/TC 287, in collaboration with ISO/TC 211 and OGC, start new work on the
following items:
 catalogue server;
 XML encoding of portrayal;
 quality aspects of services;
 standards for registries for geographical items, depending on the progress on ISO 19126;
 Digital Rights Management;
 the use of web services for the transfer of large datasets.
It is further recommended that before a given standard or specification be made mandatory in a European or
national legislation, the standard be implemented and tested.
Practical experience with the implementation of a given standard may reveal that a European profile thereof is
needed.
For example, based on interoperability experiments, CEN/TC 287 has identified that European profiles of
EN ISO 19115 (metadata) and ISO 19128 (Web Map Server interface) are needed in order to enhance
interoperability in Europe and started new work on these topics.
1 Scope
This Technical Report identifies the standards, technical specifications, technical reports and guidelines,
required to implement a Spatial Data Infrastructure (SDI) in Europe. It gives recommendations as to whether
any of these items should become EN, and proposes a roadmap for future work items. It further provides
recommendations for measures to be taken in order to support implementation and maintenance of a SDI. In
so doing, the report addresses a range of topics, including:
 multi-lingual aspects,
 consistent identification of geographical items,
 conformance testing,
 geographic information metadata including catalogue service profile and guidelines, and
 WMS and WFS profiles and guidelines.
2 Considered standardisation initiatives
Being embedded in information and communication technology with a strong focus on geographic information,
a SDI will rely on a variety of standards (Figure 1). This Technical Report considers primarily material
produced by the following organisations and initiatives:
 International Organization for Standardization (ISO), including but not limited to ISO/TC 211 Geographic
Information / Geomatics;
 European Committee for Standardization (CEN), including CEN/TC 287 Geographic Information;
 Open Geospatial Consortium (OGC);
 World Wide Web Consortium (W3C).

Figure 1 – The stack of standards in support of SDIs
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
3.1
conceptual formalism
set of modelling concepts used to describe a conceptual model
[EN ISO 19101:2005]
EXAMPLE UML meta model, EXPRESS meta model.
NOTE One conceptual formalism can be expressed in several conceptual schema languages.
3.2
conceptual model
model that defines concepts of a universe of discourse
[EN ISO 19101:2005]
3.3
conceptual schema
formal description of a conceptual model
[EN ISO 19101:2005]
3.4
conceptual schema language
formal language based on a conceptual formalism for the purpose of representing conceptual schemas
[EN ISO 19101:2005]
EXAMPLE UML, EXPRESS, IDEF1X.
NOTE A conceptual schema language may be lexical or graphical. Several conceptual schema languages can be
based on the same conceptual formalism.
3.5
conformance
fulfilment of specified requirements
[EN ISO 19113:2005]
3.6
component
physical, replaceable part of a system that packages implementation and provides the realization of a set of
interfaces
[ISO/TS 19103:2005]
3.7
identifier
linguistically independent sequence of characters capable of uniquely and permanently identifying that with
which it is associated
[ISO/IEC 11179-3:2003]
3.8
interoperability
capability to communicate, execute programs, or transfer data among various functional units in a manner that
requires the user to have little or no knowledge of the unique characteristics of those units
[ISO/IEC 2382-1:1993]
3.9
reference frame
aggregation of the data needed by different components of an information system
3.10
resource
asset or means that fulfils a requirement
[EN ISO 19115:2005]
3.11
Spatial Data Infrastructure (SDI)
metadata, spatial data sets and spatial data services; network services and technologies; agreements on
sharing, access and use; coordination and monitoring mechanisms, processes and procedures, established,
operated or made available in an interoperable manner
NOTE In the context of this report the term SDI is restricted to a platform- and implementation-neutral technological
infrastructure for geospatial data and services, based upon standards and specifications.
3.12
Use Case
specification of a sequence of actions, including variants, that a system (or other entity) can perform,
interacting with actors of the system
[OMG UML Specification]
4 Abbreviated terms
API Application Programming Interface
CLA cultural and linguistic adaptability
CORBA Common Object Request Broker Architecture
DCE Distributed Computing Environment
DRM Digital Rights Management
ebXML Electronic Business using eXtensible Markup Language
EOSE Extended Open System Environment
EN European Standard (CEN deliverable)
ESDI European Spatial Data Infrastructure
INSPIRE Infrastructure for Spatial Information in Europe
GI Geographic information
GIRM Geospatial Interoperability Reference Model
GML Geography Markup Language
ISO International Organization for Standardization
IT Information Technology
NSDI National Spatial Data Infrastructure
OASIS Organization for the Advancement of Structured Information Standards
OCL Object Constraint Language
ODP Open Distributed Processing
OGC Open Geospatial Consortium
OLE/COM Object linking and embedding/ Component Object Model
OMG Object Management Group
ORM OpenGIS Reference Model
RM-ODP Reference Model of Open Distributed Processing
SDI Spatial Data Infrastructure
SLD Styled Layer Descriptor
SOA Service Oriented Architecture
SOAP Simple Object Access Protocol
UDDI Universal Description, Discovery and Integration
UML Unified Modelling Language
UUID Universally Unique Identifier
WCS Web Coverage Service interface specification
WFS Web Feature Service interface specification
WMS Web Map Service interface specification
WRS Web Registry Server
WSA Web Service Architecture
WSDL Web Service Description Language
W3C World Wide Web Consortium
XMI eXtensible Markup Interface
XML eXtensible Markup Language
5 Spatial Data Infrastructure as an implementation-neutral framework
5.1 Management summary
A SDI relies on standards and specifications in the field of geographic information and information technology.
This report systematically identifies standards that are of particular relevance to SDI development and
implementation. A conditio sine qua non for the successful establishment of a SDI is that the software industry
supports relevant standards in commercial products. At the same time, public authorities are to request the
support of standards in public procurement processes.
5.2 Standards and interoperability
The users of a SDI are considered to be those individuals or organisations that, in the context of their
business processes, need to share and access geo-resources in a meaningful and sustainable way. Based on
platform- and vendor-neutral standards and specifications, a SDI aims at assisting organisations and
individuals in publishing, finding, delivering, and eventually, using geographic information and services over
the internet across borders of information communities in a more cost-effective manner than would be
possible without the SDI in place.
A SDI relies on standards and specifications in the field of geographic information and information technology,
many of which are already available. There is, however, a need to systematically identify these standards and
to determine whether or not these standards are sufficiently precise and unambiguous so that their
implementation guarantees interoperability and fulfils requirements of a SDI in Europe.
Interoperability is the capability to communicate, execute programs, or transfer data among various functional
units in a manner that requires the user to have little or no knowledge of the unique characteristics of those
units. Standardization of geographic information can best be served by a set of standards that integrates a
detailed description of geographic information concepts with the concepts of information technology. A goal of
the GI standardization efforts is to facilitate interoperability of geographic information systems, including
interoperability in distributed computing environments. Interoperability provides the freedom to mix and match
information system components without compromising overall success (OGC, 2003), and is a basis for the
successful implementation of a SDI in Europe. A SDI in Europe will allow one to:
a) find information and processing tools, when they are needed, independent of physical location;
b) understand and employ the discovered information and tools, no matter what platform supports them;
whether local or remote;
c) integrate and combine easier and more cost-effective data originating from heterogeneous sources;
d) support policies in Europe;
e) control the evolution of a SDI.
It is anticipated that the current lack of interoperability in the field of geographic information will be resolved by
the support and implementation of international standards by software providers. This will greatly increase the
efficiency of the use of geographic information in the future.
Recommendation:
This Technical Report encourages the software industry to support standards for the creation and
management of geographic information and to implement appropriate interface specifications in their products.
It also recommends public authorities to reference relevant GI standards in public procurement processes that
are to support SDI implementations.
5.3 Generic architecture model
Figure 2 shows a generic architecture model that allows one to describe a SDI. This model is based on the
Geospatial Interoperability Reference Model (Evans, 2003). It is introduced to provide a common
understanding of the technical aspects of spatial data infrastructures. In this model, a distinction is made
between four major groups of components. In this context, the term component refers to a group of technically
similar functionalities within the architecture. The four groups of components are:
 user applications;
 geo-processing and catalogue services;
 content repositories;
 catalogues.
User applications comprise the software usually seen by users; they include general purpose interfaces for
query and viewing, a tool for database administrators, and analytical applications tailored to the information
needs of the user.
Geo-processing and catalogue services may process user queries, draw maps from data, regulate access,
perform payment operations, and extract and send data to a user application.
Content repositories provide data.
Finally, the catalogues allow clients and services to find out what repositories or services are available and
appropriate for their use. The catalogues, together with the catalogue services, are a fundamental part of any
SDI.
In addition, security, authentication and digital rights management (DRM) components are required
Client software
User applications
metadata search and
access to processed
retrieval
data, services
Security,
authentication,
DRM
direct access to data
Catalogue 1
Catalogue
Service 1
Distributed
Catalogue search and retrieval services
Catalogue Geo-processing
Service service
metadata update
service chaining,
search, display,
access, .
Geospatial data Geospatial data Geospatial data Distributed
repository 1 repository repository 2 content
repositories
Figure 2 — A generic architecture of spatial data infrastructures
5.4 Data-centric vs service-centric
In the context of this report, two possible views on a SDI are considered: the data-centric view, and the
service-centric view. These two views are discussed in detail in Clauses 6 and 7, respectively.
The data-centric view primarily addresses concerns related to the data, which includes application schemas
and metadata.
The service-centric view includes the taxonomy of services, concepts of interoperability, service architecture,
service catalogue, the underlying IT standards, and more.
5.5 SDI as a dynamic framework
A SDI should not be considered as a static framework that will offer solutions for a fixed set of requirements.
Rather, it is a dynamic framework that satisfies current requirements while at the same time generating new
needs and solutions. It also permits creation of new services and applications, and stimulates the creation of
new standards and specifications. Once a SDI is in place, there are four interesting use cases: specification
and standardisation, development, deployment and invocation. In each activity there are standards of interest.
With this in mind, a SDI can be described in terms of a set of high-level activities that reflect the evolutionary
character of a SDI.
These activities are: establish the core SDI, create new specifications, develop new services and applications,
deploy services and applications, and invoke application instances. These activities are described in Table 1.
The activity diagram in Figure 3 suggests how the SDI activities interact, thus driving the evolution of SDIs.

Develop new
Establish core SDI Dev elop new services
specifications and
and applications
standards
A core SDI
comprises basic
functionalities
such as search for
Policy drivers
Deploy services and
metadata and
determine new Invoke services and
applications
access to data
applications
requirements and
sets.
specifications
Figure 3 — Generic SDI activity diagram

Table 1 —SDI Activities
Activity Description Example
1 Establish the "core" SDI Certain basic services, paramount for the Data, metadata content,
SDI, have to be developed and launched metadata catalogues,
according to standards and service catalogues.
specifications.
Pre-condition: standards for metadata
content (services and data).
Post condition: human-readable
catalogues.
2 Develop new specifications Service interfaces are specified and Standards required for
published by interface providers. description of features

and coverage: modelling
language, spatial
representation etc.
standards for description
of presentation aspects,
portrayal.
3 Develop new services and Based on published interface Standards for certain
applications specifications, services (for example a servers: WMS, WFS,
WFS for roads) and applications (for gazetteer, transformation
example an application for goods etc.
delivery) are built by service providers
Standards for encoding.
and application providers.
Standards for finding
services.
Standards for security.
4 Deploy service and application The services are published by the service
instances providers.
The applications are provided to the
users and installed.
Standards for describing and publishing
services.
5 Invoke application instances by The user uses the application that finds Standards for evaluation.
users and calls appropriate services.

6 Data-centric view on SDI
6.1 Management summary
 The model-driven approach is promoted for ESDI.
 Unique identifiers for use in a European SDI should consist of a namespace and a UUID.
 ISO 19109 and referred standards are promoted as ESDI rules for specifying data structures and
semantics.
 UML class diagrams used according to ISO/TS 19103 is promoted as an ESDI conceptual schema
language.
 ISO 19136 (GML) is promoted as the ESDI encoding method when transferring geographic data.
 ISO 19139 is promoted as the ESDI encoding method when transferring information related to geographic
data such as metadata, feature catalogues and data dictionaries.
6.2 Development
6.2.1 The model-driven approach
The model-driven approach follows the concepts developed in the model-driven architecture defined by OMG
(OMG, 2003).
The lifetime of a technical implementation is shorter than the lifetime of the information it handles. This makes
it necessary to describe the information in a way that allows for new techniques and implementation
environments to be applied.
The (EN) ISO 19100 series of standards provide a model-driven approach: The information is described by a
formal, implementation-independent schema. Implementations for various techniques (e.g. XML file transfer,
web services, relational database) and implementation environments (e.g. J2EE, .Net) can be derived from
the schema in a more or less automatic way. Changes in information requirements are applied to the schema;
never directly to the implementation. Figure 4 depicts these principles.

Implementation-independent
Application schema
description of semantics
and logical data structure
WSDL Specification XML schema
Specifications
description of database for
for different
of Web Service tables data transfer
techniques
Product Product Product Product Product
Implementations
A B C D E
...