ISO 19144-1:2009
(Main)Geographic information — Classification systems — Part 1: Classification system structure
Geographic information — Classification systems — Part 1: Classification system structure
ISO 19144-1:2009 establishes the structure of a geographic information classification system, together with the mechanism for defining and registering the classifiers for such a system. It specifies the use of discrete coverages to represent the result of applying the classification system to a particular area and defines the technical structure of a register of classifiers in accordance with ISO 19135.
Information géographique — Systèmes de classification — Partie 1: Structure de système de classification
L'ISO 19144-1:2009 établit la structure d'un système de classification d'informations géographiques, ainsi que le mécanisme de définition et d'enregistrement des classificateurs pour un tel système. Elle spécifie l'utilisation de couvertures discrètes pour représenter le résultat de l'application du système de classification à une zone particulière et définit la structure technique d'un registre de classificateurs, conformément à l'ISO 19135.
Geografske informacije - Klasifikacijski sistemi - 1. del: Struktura klasifikacijskega sistema
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INTERNATIONAL ISO
STANDARD 19144-1
First edition
2009-08-15
Geographic information — Classification
systems —
Part 1:
Classification system structure
Information géographique — Systèmes de classification —
Partie 1: Structure de système de classification
Reference number
ISO 19144-1:2009(E)
©
ISO 2009
---------------------- Page: 1 ----------------------
ISO 19144-1:2009(E)
PDF disclaimer
This PDF file may contain embedded typefaces. In accordance with Adobe's licensing policy, this file may be printed or viewed but
shall not be edited unless the typefaces which are embedded are licensed to and installed on the computer performing the editing. In
downloading this file, parties accept therein the responsibility of not infringing Adobe's licensing policy. The ISO Central Secretariat
accepts no liability in this area.
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Details of the software products used to create this PDF file can be found in the General Info relative to the file; the PDF-creation
parameters were optimized for printing. Every care has been taken to ensure that the file is suitable for use by ISO member bodies. In
the unlikely event that a problem relating to it is found, please inform the Central Secretariat at the address given below.
COPYRIGHT PROTECTED DOCUMENT
© ISO 2009
All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized in any form or by any means,
electronic or mechanical, including photocopying and microfilm, without permission in writing from either ISO at the address below or
ISO's member body in the country of the requester.
ISO copyright office
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Tel. + 41 22 749 01 11
Fax + 41 22 749 09 47
E-mail copyright@iso.org
Web www.iso.org
Published in Switzerland
ii © ISO 2009 – All rights reserved
---------------------- Page: 2 ----------------------
ISO 19144-1:2009(E)
Contents Page
Foreword .iv
Introduction.v
1 Scope.1
2 Conformance .1
2.1 Classes .1
2.2 Conformance of a classification system.1
2.3 Conformance of a register of classifiers.1
2.4 Representation of classification results .1
3 Normative references.1
4 Terms, definitions and abbreviated terms.2
4.1 Terms and definitions .2
4.2 Abbreviated terms.4
5 Classification systems.5
5.1 Concept .5
5.2 Classification and legend .7
5.3 Hierarchical versus non-hierarchical systems.8
5.4 A priori and a posteriori classification systems .8
5.5 Structure of classified data .9
5.6 A classification data set.13
6 Management of classifiers .14
6.1 General .14
6.2 Concept dictionary register for a classification scheme .15
6.3 Management of classifiers through registration.15
6.4 Register structure.15
Annex A (normative) Abstract test suite .24
Annex B (informative) A priori and a posteriori classification systems .26
Bibliography.30
© ISO 2009 – All rights reserved iii
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ISO 19144-1:2009(E)
Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards bodies
(ISO member bodies). The work of preparing International Standards is normally carried out through ISO
technical committees. Each member body interested in a subject for which a technical committee has been
established has the right to be represented on that committee. International organizations, governmental and
non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely with the
International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization.
International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2.
The main task of technical committees is to prepare International Standards. Draft International Standards
adopted by the technical committees are circulated to the member bodies for voting. Publication as an
International Standard requires approval by at least 75 % of the member bodies casting a vote.
Attention is drawn to the possibility that some of the elements of this document may be the subject of patent
rights. ISO shall not be held responsible for identifying any or all such patent rights.
ISO 19144-1 was prepared jointly by the Food and Agriculture Organization (FAO) of the United Nations and
Technical Committee ISO/TC 211, Geographic information/Geomatics under a cooperative agreement
between the two organizations.
ISO 19144 consists of the following parts, under the general title Geographic information — Classification
systems:
⎯ Part 1: Classification system structure
The following part is under preparation:
⎯ Part 2: Land cover classification system (LCCS)
iv © ISO 2009 – All rights reserved
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ISO 19144-1:2009(E)
Introduction
This part of ISO 19144 is based on publications of the Food and Agriculture Organization (FAO) of the United
[1][2]
Nations . The first in a series of International Standards related to geographic classification systems, it
defines the structure of such systems, together with the mechanism for defining and registering classifiers.
Since there are many different possible application areas, there is no single classification system that will
serve all needs. The method by which classifiers are defined depends upon the application area. In addition,
the classifiers used within a particular application area might not be adequate for all situations encountered
within that application area and could need to be augmented over time. To facilitate extension of the set of
classifiers in a particular application area, classifiers are registered in a register structure compliant with
ISO 19135. This allows the set of classifiers to be maintained. The use of the ISO 19135 registration
mechanism allows for separate registers to be defined for different sets of classifiers within multiple
information communities, thereby satisfying application needs. This approach allows for independence
between information communities, but also allows relationships to be developed between different
classification systems that potentially allow the conversion, or partial conversion, of data from one
classification system to another, or the fusion of data from two separate sources.
The concept of classification systems is well known in the geographic information community. A classification
system can be used to subdivide any geographic area into small units, each of which carries an identifier that
describes its type. The results can then be represented as a discrete coverage as described in ISO 19123.
Many such classification systems can be defined to address any geographic area. Different application areas
and different information communities can define their own classification systems. However, if the
classification system is defined in a compatible way, interaction between different information communities
becomes possible. In addition, in a particular application area, it is desirable that there be a few
well-established classification systems, and that these themselves be standardized within information
communities.
This part of ISO 19144 describes the common structure, while subsequent parts will allow for the
standardization of specific classification systems.
A coverage is a function that returns values from its range for any direct position within its spatial, temporal or
spatiotemporal domain. A discrete coverage is a function that returns the same feature attribute values for
every direct position within any single spatial object, temporal object or spatiotemporal object in its domain.
The domain is an area covered by the coverage function, and the discrete coverage breaks that area down
into a set of spatial, temporal or spatiotemporal objects. The geometry of the discrete coverage used to
represent the results of applying a classification system can be any type of discrete coverage — for example,
a set of polygons fitted together like a jig-saw puzzle, a set of grid cells, or a set of points or curves.
A classification system consists of a set of classifiers. These classifiers may be algorithmically defined, or
established according to a set of classification system definitions. The classifiers are
application-area-dependent and are or will be defined in the other parts of ISO 19144 or other standards or
publications. A register allows for the maintenance of a set of classifiers for a particular application area. A
spatial, temporal or spatiotemporal object defined in terms of a set of classifiers is a classified object.
There is a commonality between conventional geographic features and classified objects. A feature is defined
in ISO 19101 as an abstraction of real world phenomena. An example of a class of feature is a building, and a
particular building, e.g. the UN building in New York, is an instance of a feature class. Conventional
geographic features are atomic units that are assembled to build one type of geographic information data set.
A classification system works in the opposite manner, from the top down, by successively decomposing the
whole within a coverage area. Classified objects are features, in that they are an abstraction of a real world
phenomena, but classified objects are not atomic, because they are necessarily related to each other by the
classifiers that decompose the whole. In a simple example of a classification system, the earth as a whole can
be covered by either “land” or “water”, and two classifiers can be defined partitioning the attribute range into
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ISO 19144-1:2009(E)
two, identifying objects as being either land or water. Any particular area on the earth, corresponding to a
classified object, would be of type “land” or “water”.
ISO 19135 specifies that a technical standard be required to define the item classes in any conformant
register. This part of ISO 19144 defines schemas for registers conformant to ISO 19135 and serves as the
technical standard that defines the item classes required for the registration of classifiers. It establishes a set
of rules for specifying definitions that can be used in a particular context to establish classified objects.
Registers of classifiers can serve as sources of reference for similar registers established by other geographic
information communities as part of a system of cross-referencing. Cross-referencing between respective items
in registers of classifiers might be difficult in cases where the structure of registers differs between information
communities. This part of ISO 19144 can serve as a guide for different information communities for the
development of compatible registers that can support a system of classifier cross-referencing.
The structure of a classification system together with the mechanism of defining and registering classifiers
defined in this part of ISO 19144 is general and can be applied to many different information-community-
defined classification systems, including soil, landform, vegetation, urbanization and systems for
understanding biodiversity and climate change. The use of this document will allow the relationship between
different classification systems to be described.
vi © ISO 2009 – All rights reserved
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INTERNATIONAL STANDARD ISO 19144-1:2009(E)
Geographic information — Classification systems —
Part 1:
Classification system structure
1 Scope
This part of ISO 19144 establishes the structure of a geographic information classification system, together
with the mechanism for defining and registering the classifiers for such a system. It specifies the use of
discrete coverages to represent the result of applying the classification system to a particular area and defines
the technical structure of a register of classifiers in accordance with ISO 19135.
The structure can be used to develop specific classification systems that address particular application areas,
specified in other parts of ISO 19144.
2 Conformance
2.1 Classes
Three conformance classes are identified in this part of ISO 19144.
2.2 Conformance of a classification system
Any classification system for which conformance to this part of ISO 19144 is claimed shall be in accordance
with Annex A (see A.2).
2.3 Conformance of a register of classifiers
Any register of classifiers for which conformance to this part of ISO 19144 is claimed shall be in accordance
with Annex A (see A.3) and ISO 19135:2005, A.1.
2.4 Representation of classification results
Any legend of classifiers for which conformance to this part of ISO 19144 is claimed shall be in accordance
with Annex A (see A.4).
3 Normative references
The following referenced documents are indispensable for the application of this document. For dated
references, only the edition cited applies. For undated references, the latest edition of the referenced
document (including any amendments) applies.
ISO/TS 19103:2005, Geographic information — Conceptual schema language
ISO 19110:2005, Geographic information — Methodology for feature cataloguing
ISO 19115, Geographic information — Metadata
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ISO 19144-1:2009(E)
ISO 19123, Geographic information — Schema for coverage geometry and functions
ISO 19135:2005, Geographic information — Procedures for item registration
4 Terms, definitions and abbreviated terms
For the purposes of this document, the following terms, definitions and abbreviated terms apply.
4.1 Terms and definitions
4.1.1
a posteriori classification
classification (4.1.4) scheme based upon definition of classes after clustering the field samples collected
NOTE 1 Taken from FAO LCCS version 2 (see Reference [2]).
NOTE 2 See Annex B for an examination of this and a priori classification (4.1.2).
4.1.2
a priori classification
classification (4.1.4) scheme structured so that the classes are abstract conceptualizations of the types
actually occurring
NOTE 1 Taken from FAO LCCS version 2 (see Reference [2]).
NOTE 2 The approach is based upon the definition of classes before any data collection actually takes place.
NOTE 3 See Annex B for an examination of this and a posteriori classification (4.1.1).
4.1.3
classified object
spatial object, temporal object or spatiotemporal object assigned to a specific legend class (4.1.16)
4.1.4
classification
abstract representation of real world phenomena using classifiers (4.1.6)
4.1.5
classification system
system for assigning objects to classes
4.1.6
classifier
definition used to assign objects to legend classes (4.1.16)
NOTE Classifiers can be defined algorithmically or according to a set of classification system (4.1.5) specific rules.
4.1.7
coverage
feature (4.1.10) that acts as a function to return values from its range (4.1.17) for any direct position within its
spatial, temporal or spatiotemporal domain (4.1.9)
[ISO 19123:2005]
EXAMPLE Raster image, polygon overlay, digital elevation matrix.
NOTE A coverage is a feature that has multiple values for each attribute type, where each direct position within the
geometric representation of the feature has a single value for each attribute type.
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ISO 19144-1:2009(E)
4.1.8
discrete coverage
coverage (4.1.7) that returns the same feature attribute (4.1.11) values for every direct position within any
single spatial object, temporal object, or spatiotemporal object in its domain (4.1.9)
[ISO 19123:2005]
NOTE The domain of a discrete coverage consists of a finite set of spatial, temporal, or spatiotemporal objects.
4.1.9
domain
well-defined set
[ISO/TS 19103:2005]
NOTE Domains are used to define the domain and range (4.1.17) of operators and functions.
4.1.10
feature
abstraction of real world phenomena
[ISO 19101:2002]
EXAMPLE The phenomenon “Eiffel Tower” can be classified with other similar phenomena into a feature type
“tower”.
NOTE A feature can occur as a type or an instance. In this part of ISO 19144, type is meant unless otherwise
specified.
4.1.11
feature attribute
characteristic of a feature (4.1.10)
[ISO 19101:2002]
4.1.12
feature concept dictionary
dictionary that contains definitions of, and related descriptive information about concepts that may be specified
in detail in a feature (4.1.10) catalogue
1)
[ISO 19126:— ]
4.1.13
identifier
linguistically independent sequence of characters capable of uniquely and permanently identifying that with
which it is associated
[ISO 19135:2005]
4.1.14
item class
set of items with common properties
[ISO 19135:2005]
NOTE “Class” is used in this context to refer to a set of instances, not the concept abstracted from that set of
instances.
1) To be published.
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ISO 19144-1:2009(E)
4.1.15
legend
application of a classification (4.1.4) in a specific area using a defined mapping scale and specific data set
NOTE Taken from FAO LCCS version 2 (see Reference [2]).
4.1.16
legend class
class resultant from the application of a classification (4.1.4) process
NOTE The result of a classification process is termed legend class in this part of ISO 19144 in order to avoid
confusion with the term “class” as used in UML modelling.
4.1.17
range
〈coverage〉 set of feature attribute (4.1.11) values associated by a function with the elements of the
domain (4.1.9) of a coverage (4.1.7)
[ISO 19123:2005]
4.1.18
register
set of files containing identifiers (4.1.13) assigned to items with descriptions of the associated items
[ISO 19135:2005]
4.1.19
registry
information system on which a register (4.1.18) is maintained
[ISO 19135:2005]
4.1.20
technical standard
standard containing the definitions of item classes (4.1.14) requiring registration
[ISO 19135:2005]
4.1.21
vector geometry
representation of geometry through the use of constructive geometric primitives
[ISO 19107:2003]
4.2 Abbreviated terms
4.2.1 General
CRS Coordinate Reference System
LCCS Land Cover Classification System
UML Unified Modelling Language
4.2.2 Notation
The conceptual schema specified in this part of ISO 19144 is described using the Unified Modelling Language
(UML), following the guidance of ISO/TS 19103.
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ISO 19144-1:2009(E)
Several model elements used in this schema are defined in other standards in the ISO 19100 series. By
2)
convention within this suite of International Standards, names of UML classes , with the exception of basic
data type classes, include a two-letter prefix that identifies the International Standard and the UML package in
which the class is defined.
UML classes defined in this part of ISO 19144 have the two-letter prefix “CL”.
Table 1 lists the other International Standards and the packages in which UML classes used in this part of
ISO 19144 have been defined.
Table 1 — Sources of externally defined UML classes
International
Prefix Package
Standard
CV ISO 19123 Coverage core and discrete coverages
DS ISO 19115 Metadata application information
GF ISO 19109 General feature model
GM ISO 19107 Geometry root
MD ISO 19115 Metadata entity set information
MI ISO 19115-2 Metadata entity set imagery
RE ISO 19135 Procedures for registration
SC ISO 19111 Spatial referencing by coordinates
TM ISO 19108 Temporal objects
5 Classification systems
5.1 Concept
A discrete coverage returns the same feature attribute for every direct position within any single geometric
object in its spatiotemporal domain. The spatiotemporal domain consists of a set of geometric objects that
together form the coverage.
EXAMPLE 1 The discrete coverage of postal zones within a country: each zone has a different code and it is not
possible to interpolate between these codes. Nevertheless, there could be a high level relationship between the codes.
The small country of Monaco is divided into five quartiers: “Moneghetti”, “La Condamine”, “Fontvieille”, “Monaco-Ville” and
“Monte-Carlo”. These political jurisdictions completely cover the area of the country. The area of Monaco can be
represented as a discrete coverage with five spatial objects where each object has the geometry of a polygon. The
attribute value for each spatial object is the name of the political jurisdiction. See Figure 1.
2) There is potential confusion between the use of the term “class” as used in UML, “class” as used in a classification
scheme and “item class” as used in the procedures for registration. Class as used in a classification scheme is termed
legend class in this part of ISO 19144.
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ISO 19144-1:2009(E)
Moneghetti La Condamine
Monte-Carlo
Monaco
Fontvieille Monaco-Ville
Figure 1 — Example of discrete coverage with polygon geometry
The geometry of the spatial objects associated with a discrete coverage can also be grid cells within a grid
structure. Each of the grid cells may carry an attribute.
EXAMPLE 2 A discrete coverage with grid geometry of the same area as used in the previous example. See Figure 2.
The figure legend identifies the instances of the attribute values that actually exist in the data.
Monte-Carlo
Monaco
Moneghetti
Monaco-Ville
Fontvieille
La Condamine
Figure 2 — Example of discrete coverage with grid geometry
NOTE The discrete coverages illustrated by the above examples are simple because only one relatively simple
attribute has been used. However, in reality the attributes for each of the coverage spatial objects can be very complex. In
order to describe land cover it is necessary to integrate a large number of descriptive parameters related to soil, biology
and density into a comprehensive land cover classification system. Such a classification system is of course
application-area-dependent. An oceanographer will have a different classification system than that of a meteorologist.
Classification systems can vary widely in different application areas, but for similar application areas there needs to be
some commonality in order for data from different sources to be used together.
6 © ISO 2009 – All rights reserved
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ISO 19144-1:2009(E)
A classification system allows one to define classifiers in order to partition the attribute range of a discrete
coverage to establish classified objects.
5.2 Classification and legend
Classification is an abstract representation of real world phenomena (i.e. the situation in the field) using
classifiers. A classification is a systematic framework with the names of the classes and the definitions used to
distinguish them, and the relation between classes. Classification thus necessarily involves definition of class
boundaries that must be clear and based upon objective criteria.
A classification system shall be
⎯ scale independent, meaning that the classes at all levels of the system shall be applicable at any scale or
level of detail, and
⎯ source independent, implying that it is independent of the means used to collect information.
NOTE 1 Scale independence and source independence exist in the general case of a classification system. When the
system is applied to real data, i.e. when a legend is created, the scale and source limitations of the data can create
restrictions on the legend.
A legend is the application of a classification in a specific area using a defined mapping scale and specific
data set. Therefore, a legend may contain only a proportion, or subset, of all possible classes of the
classification.
A legend shall be
⎯ scale dependent, and
⎯ source dependent.
EXAMPLE 1 Scale dependence: some elements might be too small to be delineated independently when collected at
a particular scale.
EXAMPLE 2 Source dependence: elements collected from different sources, such as an aerial photograph and a
satellite false colour composite image, could be different.
A legend is a selection of a set of the classifiers from all of the possible classifiers within a classification
system. A legend could correspond to the classifiers that apply to a single data set or it could be applicable to
a number of related data sets.
NOTE 2 A legend is analogous to the set of features within a feature catalogue, which is a subset of all of the possible
features within a feature concept dictionary.
EXAMPLE 3 The derivation of legend classes from a classification system: when applying the reference classification
system to a given geographic area with a specific data type, only a subset of the classes from the reference system will
occur in the real data. This set of classes is the legend with which the mapping system will be carried out. The reference
system in Figure 3 is shown as a matrix with two parameters: the height of plants, ranging from 5 m to greater than 50 m,
and the percentage crown cover, ranging from less than 10 % to 100 %. The classes are numbered with a code number
from 1 to 100. In this specific case, the legend will have only four reference classification classes, numbers 33, 47, 78 and
83.
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ISO 19144-1:2009(E)
Reference Classification System
>50 m 30 m >5 m
12 3 4
100%
DEFINED
GEOGRAPHIC
33
47 AREA
50%
78
given scale and data type
83
97 98 99 100
10%
mapping
derived
units
legend
[2]
Figure 3 — Legend as application of classification in a particular area
5.3 Hierarchical versus non-hierarchical systems
There are two basic forms of classification system: hierarchical and non-hierarchical.
a) Hierarchical classification systems
⎯ Classifiers shall be defined so that all classes at a specific level of the hierarchy are mutually
exclusive.
⎯ Criteria used to define a classifier at one level of a hierarchical classification shall not be repeated at
another level (e.g. criteria used to define a classifier at a lower level shall not be duplicated to a
higher level of the hierarchy).
NOTE 1 Most classification systems are hierarchically structured. Such a classification offers greater consistency,
owing to its ability to accommodate different levels of information — starting with structured broad-level classes —
which allow f
...
SLOVENSKI STANDARD
SIST ISO 19144-1:2009
01-december-2009
Geografske informacije - Klasifikacijski sistemi - 1. del: Struktura klasifikacijskega
sistema
Geographic information - Classification systems - Part 1: Classification system structure
Information géographique - Systèmes de classification - Partie 1: Structure de système
de classification
Ta slovenski standard je istoveten z: ISO 19144-1:2009
ICS:
35.240.70 Uporabniške rešitve IT v IT applications in science
znanosti
SIST ISO 19144-1:2009 en
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
---------------------- Page: 1 ----------------------
SIST ISO 19144-1:2009
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SIST ISO 19144-1:2009
INTERNATIONAL ISO
STANDARD 19144-1
First edition
2009-08-15
Geographic information — Classification
systems —
Part 1:
Classification system structure
Information géographique — Systèmes de classification —
Partie 1: Structure de système de classification
Reference number
ISO 19144-1:2009(E)
©
ISO 2009
---------------------- Page: 3 ----------------------
SIST ISO 19144-1:2009
ISO 19144-1:2009(E)
PDF disclaimer
This PDF file may contain embedded typefaces. In accordance with Adobe's licensing policy, this file may be printed or viewed but
shall not be edited unless the typefaces which are embedded are licensed to and installed on the computer performing the editing. In
downloading this file, parties accept therein the responsibility of not infringing Adobe's licensing policy. The ISO Central Secretariat
accepts no liability in this area.
Adobe is a trademark of Adobe Systems Incorporated.
Details of the software products used to create this PDF file can be found in the General Info relative to the file; the PDF-creation
parameters were optimized for printing. Every care has been taken to ensure that the file is suitable for use by ISO member bodies. In
the unlikely event that a problem relating to it is found, please inform the Central Secretariat at the address given below.
COPYRIGHT PROTECTED DOCUMENT
© ISO 2009
All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized in any form or by any means,
electronic or mechanical, including photocopying and microfilm, without permission in writing from either ISO at the address below or
ISO's member body in the country of the requester.
ISO copyright office
Case postale 56 • CH-1211 Geneva 20
Tel. + 41 22 749 01 11
Fax + 41 22 749 09 47
E-mail copyright@iso.org
Web www.iso.org
Published in Switzerland
ii © ISO 2009 – All rights reserved
---------------------- Page: 4 ----------------------
SIST ISO 19144-1:2009
ISO 19144-1:2009(E)
Contents Page
Foreword .iv
Introduction.v
1 Scope.1
2 Conformance .1
2.1 Classes .1
2.2 Conformance of a classification system.1
2.3 Conformance of a register of classifiers.1
2.4 Representation of classification results .1
3 Normative references.1
4 Terms, definitions and abbreviated terms.2
4.1 Terms and definitions .2
4.2 Abbreviated terms.4
5 Classification systems.5
5.1 Concept .5
5.2 Classification and legend .7
5.3 Hierarchical versus non-hierarchical systems.8
5.4 A priori and a posteriori classification systems .8
5.5 Structure of classified data .9
5.6 A classification data set.13
6 Management of classifiers .14
6.1 General .14
6.2 Concept dictionary register for a classification scheme .15
6.3 Management of classifiers through registration.15
6.4 Register structure.15
Annex A (normative) Abstract test suite .24
Annex B (informative) A priori and a posteriori classification systems .26
Bibliography.30
© ISO 2009 – All rights reserved iii
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SIST ISO 19144-1:2009
ISO 19144-1:2009(E)
Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards bodies
(ISO member bodies). The work of preparing International Standards is normally carried out through ISO
technical committees. Each member body interested in a subject for which a technical committee has been
established has the right to be represented on that committee. International organizations, governmental and
non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely with the
International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization.
International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2.
The main task of technical committees is to prepare International Standards. Draft International Standards
adopted by the technical committees are circulated to the member bodies for voting. Publication as an
International Standard requires approval by at least 75 % of the member bodies casting a vote.
Attention is drawn to the possibility that some of the elements of this document may be the subject of patent
rights. ISO shall not be held responsible for identifying any or all such patent rights.
ISO 19144-1 was prepared jointly by the Food and Agriculture Organization (FAO) of the United Nations and
Technical Committee ISO/TC 211, Geographic information/Geomatics under a cooperative agreement
between the two organizations.
ISO 19144 consists of the following parts, under the general title Geographic information — Classification
systems:
⎯ Part 1: Classification system structure
The following part is under preparation:
⎯ Part 2: Land cover classification system (LCCS)
iv © ISO 2009 – All rights reserved
---------------------- Page: 6 ----------------------
SIST ISO 19144-1:2009
ISO 19144-1:2009(E)
Introduction
This part of ISO 19144 is based on publications of the Food and Agriculture Organization (FAO) of the United
[1][2]
Nations . The first in a series of International Standards related to geographic classification systems, it
defines the structure of such systems, together with the mechanism for defining and registering classifiers.
Since there are many different possible application areas, there is no single classification system that will
serve all needs. The method by which classifiers are defined depends upon the application area. In addition,
the classifiers used within a particular application area might not be adequate for all situations encountered
within that application area and could need to be augmented over time. To facilitate extension of the set of
classifiers in a particular application area, classifiers are registered in a register structure compliant with
ISO 19135. This allows the set of classifiers to be maintained. The use of the ISO 19135 registration
mechanism allows for separate registers to be defined for different sets of classifiers within multiple
information communities, thereby satisfying application needs. This approach allows for independence
between information communities, but also allows relationships to be developed between different
classification systems that potentially allow the conversion, or partial conversion, of data from one
classification system to another, or the fusion of data from two separate sources.
The concept of classification systems is well known in the geographic information community. A classification
system can be used to subdivide any geographic area into small units, each of which carries an identifier that
describes its type. The results can then be represented as a discrete coverage as described in ISO 19123.
Many such classification systems can be defined to address any geographic area. Different application areas
and different information communities can define their own classification systems. However, if the
classification system is defined in a compatible way, interaction between different information communities
becomes possible. In addition, in a particular application area, it is desirable that there be a few
well-established classification systems, and that these themselves be standardized within information
communities.
This part of ISO 19144 describes the common structure, while subsequent parts will allow for the
standardization of specific classification systems.
A coverage is a function that returns values from its range for any direct position within its spatial, temporal or
spatiotemporal domain. A discrete coverage is a function that returns the same feature attribute values for
every direct position within any single spatial object, temporal object or spatiotemporal object in its domain.
The domain is an area covered by the coverage function, and the discrete coverage breaks that area down
into a set of spatial, temporal or spatiotemporal objects. The geometry of the discrete coverage used to
represent the results of applying a classification system can be any type of discrete coverage — for example,
a set of polygons fitted together like a jig-saw puzzle, a set of grid cells, or a set of points or curves.
A classification system consists of a set of classifiers. These classifiers may be algorithmically defined, or
established according to a set of classification system definitions. The classifiers are
application-area-dependent and are or will be defined in the other parts of ISO 19144 or other standards or
publications. A register allows for the maintenance of a set of classifiers for a particular application area. A
spatial, temporal or spatiotemporal object defined in terms of a set of classifiers is a classified object.
There is a commonality between conventional geographic features and classified objects. A feature is defined
in ISO 19101 as an abstraction of real world phenomena. An example of a class of feature is a building, and a
particular building, e.g. the UN building in New York, is an instance of a feature class. Conventional
geographic features are atomic units that are assembled to build one type of geographic information data set.
A classification system works in the opposite manner, from the top down, by successively decomposing the
whole within a coverage area. Classified objects are features, in that they are an abstraction of a real world
phenomena, but classified objects are not atomic, because they are necessarily related to each other by the
classifiers that decompose the whole. In a simple example of a classification system, the earth as a whole can
be covered by either “land” or “water”, and two classifiers can be defined partitioning the attribute range into
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two, identifying objects as being either land or water. Any particular area on the earth, corresponding to a
classified object, would be of type “land” or “water”.
ISO 19135 specifies that a technical standard be required to define the item classes in any conformant
register. This part of ISO 19144 defines schemas for registers conformant to ISO 19135 and serves as the
technical standard that defines the item classes required for the registration of classifiers. It establishes a set
of rules for specifying definitions that can be used in a particular context to establish classified objects.
Registers of classifiers can serve as sources of reference for similar registers established by other geographic
information communities as part of a system of cross-referencing. Cross-referencing between respective items
in registers of classifiers might be difficult in cases where the structure of registers differs between information
communities. This part of ISO 19144 can serve as a guide for different information communities for the
development of compatible registers that can support a system of classifier cross-referencing.
The structure of a classification system together with the mechanism of defining and registering classifiers
defined in this part of ISO 19144 is general and can be applied to many different information-community-
defined classification systems, including soil, landform, vegetation, urbanization and systems for
understanding biodiversity and climate change. The use of this document will allow the relationship between
different classification systems to be described.
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INTERNATIONAL STANDARD ISO 19144-1:2009(E)
Geographic information — Classification systems —
Part 1:
Classification system structure
1 Scope
This part of ISO 19144 establishes the structure of a geographic information classification system, together
with the mechanism for defining and registering the classifiers for such a system. It specifies the use of
discrete coverages to represent the result of applying the classification system to a particular area and defines
the technical structure of a register of classifiers in accordance with ISO 19135.
The structure can be used to develop specific classification systems that address particular application areas,
specified in other parts of ISO 19144.
2 Conformance
2.1 Classes
Three conformance classes are identified in this part of ISO 19144.
2.2 Conformance of a classification system
Any classification system for which conformance to this part of ISO 19144 is claimed shall be in accordance
with Annex A (see A.2).
2.3 Conformance of a register of classifiers
Any register of classifiers for which conformance to this part of ISO 19144 is claimed shall be in accordance
with Annex A (see A.3) and ISO 19135:2005, A.1.
2.4 Representation of classification results
Any legend of classifiers for which conformance to this part of ISO 19144 is claimed shall be in accordance
with Annex A (see A.4).
3 Normative references
The following referenced documents are indispensable for the application of this document. For dated
references, only the edition cited applies. For undated references, the latest edition of the referenced
document (including any amendments) applies.
ISO/TS 19103:2005, Geographic information — Conceptual schema language
ISO 19110:2005, Geographic information — Methodology for feature cataloguing
ISO 19115, Geographic information — Metadata
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ISO 19123, Geographic information — Schema for coverage geometry and functions
ISO 19135:2005, Geographic information — Procedures for item registration
4 Terms, definitions and abbreviated terms
For the purposes of this document, the following terms, definitions and abbreviated terms apply.
4.1 Terms and definitions
4.1.1
a posteriori classification
classification (4.1.4) scheme based upon definition of classes after clustering the field samples collected
NOTE 1 Taken from FAO LCCS version 2 (see Reference [2]).
NOTE 2 See Annex B for an examination of this and a priori classification (4.1.2).
4.1.2
a priori classification
classification (4.1.4) scheme structured so that the classes are abstract conceptualizations of the types
actually occurring
NOTE 1 Taken from FAO LCCS version 2 (see Reference [2]).
NOTE 2 The approach is based upon the definition of classes before any data collection actually takes place.
NOTE 3 See Annex B for an examination of this and a posteriori classification (4.1.1).
4.1.3
classified object
spatial object, temporal object or spatiotemporal object assigned to a specific legend class (4.1.16)
4.1.4
classification
abstract representation of real world phenomena using classifiers (4.1.6)
4.1.5
classification system
system for assigning objects to classes
4.1.6
classifier
definition used to assign objects to legend classes (4.1.16)
NOTE Classifiers can be defined algorithmically or according to a set of classification system (4.1.5) specific rules.
4.1.7
coverage
feature (4.1.10) that acts as a function to return values from its range (4.1.17) for any direct position within its
spatial, temporal or spatiotemporal domain (4.1.9)
[ISO 19123:2005]
EXAMPLE Raster image, polygon overlay, digital elevation matrix.
NOTE A coverage is a feature that has multiple values for each attribute type, where each direct position within the
geometric representation of the feature has a single value for each attribute type.
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4.1.8
discrete coverage
coverage (4.1.7) that returns the same feature attribute (4.1.11) values for every direct position within any
single spatial object, temporal object, or spatiotemporal object in its domain (4.1.9)
[ISO 19123:2005]
NOTE The domain of a discrete coverage consists of a finite set of spatial, temporal, or spatiotemporal objects.
4.1.9
domain
well-defined set
[ISO/TS 19103:2005]
NOTE Domains are used to define the domain and range (4.1.17) of operators and functions.
4.1.10
feature
abstraction of real world phenomena
[ISO 19101:2002]
EXAMPLE The phenomenon “Eiffel Tower” can be classified with other similar phenomena into a feature type
“tower”.
NOTE A feature can occur as a type or an instance. In this part of ISO 19144, type is meant unless otherwise
specified.
4.1.11
feature attribute
characteristic of a feature (4.1.10)
[ISO 19101:2002]
4.1.12
feature concept dictionary
dictionary that contains definitions of, and related descriptive information about concepts that may be specified
in detail in a feature (4.1.10) catalogue
1)
[ISO 19126:— ]
4.1.13
identifier
linguistically independent sequence of characters capable of uniquely and permanently identifying that with
which it is associated
[ISO 19135:2005]
4.1.14
item class
set of items with common properties
[ISO 19135:2005]
NOTE “Class” is used in this context to refer to a set of instances, not the concept abstracted from that set of
instances.
1) To be published.
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4.1.15
legend
application of a classification (4.1.4) in a specific area using a defined mapping scale and specific data set
NOTE Taken from FAO LCCS version 2 (see Reference [2]).
4.1.16
legend class
class resultant from the application of a classification (4.1.4) process
NOTE The result of a classification process is termed legend class in this part of ISO 19144 in order to avoid
confusion with the term “class” as used in UML modelling.
4.1.17
range
〈coverage〉 set of feature attribute (4.1.11) values associated by a function with the elements of the
domain (4.1.9) of a coverage (4.1.7)
[ISO 19123:2005]
4.1.18
register
set of files containing identifiers (4.1.13) assigned to items with descriptions of the associated items
[ISO 19135:2005]
4.1.19
registry
information system on which a register (4.1.18) is maintained
[ISO 19135:2005]
4.1.20
technical standard
standard containing the definitions of item classes (4.1.14) requiring registration
[ISO 19135:2005]
4.1.21
vector geometry
representation of geometry through the use of constructive geometric primitives
[ISO 19107:2003]
4.2 Abbreviated terms
4.2.1 General
CRS Coordinate Reference System
LCCS Land Cover Classification System
UML Unified Modelling Language
4.2.2 Notation
The conceptual schema specified in this part of ISO 19144 is described using the Unified Modelling Language
(UML), following the guidance of ISO/TS 19103.
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Several model elements used in this schema are defined in other standards in the ISO 19100 series. By
2)
convention within this suite of International Standards, names of UML classes , with the exception of basic
data type classes, include a two-letter prefix that identifies the International Standard and the UML package in
which the class is defined.
UML classes defined in this part of ISO 19144 have the two-letter prefix “CL”.
Table 1 lists the other International Standards and the packages in which UML classes used in this part of
ISO 19144 have been defined.
Table 1 — Sources of externally defined UML classes
International
Prefix Package
Standard
CV ISO 19123 Coverage core and discrete coverages
DS ISO 19115 Metadata application information
GF ISO 19109 General feature model
GM ISO 19107 Geometry root
MD ISO 19115 Metadata entity set information
MI ISO 19115-2 Metadata entity set imagery
RE ISO 19135 Procedures for registration
SC ISO 19111 Spatial referencing by coordinates
TM ISO 19108 Temporal objects
5 Classification systems
5.1 Concept
A discrete coverage returns the same feature attribute for every direct position within any single geometric
object in its spatiotemporal domain. The spatiotemporal domain consists of a set of geometric objects that
together form the coverage.
EXAMPLE 1 The discrete coverage of postal zones within a country: each zone has a different code and it is not
possible to interpolate between these codes. Nevertheless, there could be a high level relationship between the codes.
The small country of Monaco is divided into five quartiers: “Moneghetti”, “La Condamine”, “Fontvieille”, “Monaco-Ville” and
“Monte-Carlo”. These political jurisdictions completely cover the area of the country. The area of Monaco can be
represented as a discrete coverage with five spatial objects where each object has the geometry of a polygon. The
attribute value for each spatial object is the name of the political jurisdiction. See Figure 1.
2) There is potential confusion between the use of the term “class” as used in UML, “class” as used in a classification
scheme and “item class” as used in the procedures for registration. Class as used in a classification scheme is termed
legend class in this part of ISO 19144.
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Moneghetti La Condamine
Monte-Carlo
Monaco
Fontvieille Monaco-Ville
Figure 1 — Example of discrete coverage with polygon geometry
The geometry of the spatial objects associated with a discrete coverage can also be grid cells within a grid
structure. Each of the grid cells may carry an attribute.
EXAMPLE 2 A discrete coverage with grid geometry of the same area as used in the previous example. See Figure 2.
The figure legend identifies the instances of the attribute values that actually exist in the data.
Monte-Carlo
Monaco
Moneghetti
Monaco-Ville
Fontvieille
La Condamine
Figure 2 — Example of discrete coverage with grid geometry
NOTE The discrete coverages illustrated by the above examples are simple because only one relatively simple
attribute has been used. However, in reality the attributes for each of the coverage spatial objects can be very complex. In
order to describe land cover it is necessary to integrate a large number of descriptive parameters related to soil, biology
and density into a comprehensive land cover classification system. Such a classification system is of course
application-area-dependent. An oceanographer will have a different classification system than that of a meteorologist.
Classification systems can vary widely in different application areas, but for similar application areas there needs to be
some commonality in order for data from different sources to be used together.
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A classification system allows one to define classifiers in order to partition the attribute range of a discrete
coverage to establish classified objects.
5.2 Classification and legend
Classification is an abstract representation of real world phenomena (i.e. the situation in the field) using
classifiers. A classification is a systematic framework with the names of the classes and the definitions used to
distinguish them, and the relation between classes. Classification thus necessarily involves definition of class
boundaries that must be clear and based upon objective criteria.
A classification system shall be
⎯ scale independent, meaning that the classes at all levels of the system shall be applicable at any scale or
level of detail, and
⎯ source independent, implying that it is independent of the means used to collect information.
NOTE 1 Scale independence and source independence exist in the general case of a classification system. When the
system is applied to real data, i.e. when a legend is created, the scale and source limitations of the data can create
restrictions on the legend.
A legend is the application of a classification in a specific area using a defined mapping scale and specific
data set. Therefore, a legend may contain only a proportion, or subset, of all possible classes of the
classification.
A legend shall be
⎯ scale dependent, and
⎯ source dependent.
EXAMPLE 1 Scale dependence: some elements might be too small to be delineated independently when collected at
a particular scale.
EXAMPLE 2 Source dependence: elements collected from different sources, such as an aerial photograph and a
satellite false colour composite image, could be different.
A legend is a selection of a set of the classifiers from all of the possible classifiers within a classification
system. A legend could correspond to the classifiers that apply to a single data set or it could be applicable to
a number of related data sets.
NOTE 2 A legend is analogous to the set of features within a feature catalogue, which is a subset of all of the possible
features within a feature concept dictionary.
EXAMPLE 3 The derivation of legend classes from a classification system: when applying the reference classification
system to a given geographic area with a specific data type, only a subset of the classes from the reference system will
occur in the real data. This set of classes is the legend with which the mapping system will be carried out. The reference
system in Figure 3 is shown as a matrix with two parameters: the height of plants, ranging from 5 m to greater than 50 m,
and the percentage crown cover, ranging from less than 10 % to 100 %. The classes are numbered with a code number
from 1 to 100. In this specific case, the legend will have only four reference classification classes, numbers 33, 47, 78 and
83.
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...
NORME ISO
INTERNATIONALE 19144-1
Première édition
2009-08-15
Information géographique — Systèmes
de classification —
Partie 1:
Structure de système de classification
Geographic information — Classification systems —
Part 1: Classification system structure
Numéro de référence
ISO 19144-1:2009(F)
©
ISO 2009
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ISO 19144-1:2009(F)
DOCUMENT PROTÉGÉ PAR COPYRIGHT
© ISO 2009
Droits de reproduction réservés. Sauf prescription différente, aucune partie de cette publication ne peut être reproduite ni utilisée sous
quelque forme que ce soit et par aucun procédé, électronique ou mécanique, y compris la photocopie et les microfilms, sans l’accord écrit
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Version française parue en 2012
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ii © ISO 2009 – Tous droits réservés
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ISO 19144-1:2009(F)
Sommaire Page
Avant-propos .iv
Introduction . v
1 Domaine d’application . 1
2 Conformité . 1
2.1 Classes . 1
2.2 Conformité d’un système de classification . 1
2.3 Conformité d’un registre de classificateurs . 1
2.4 Représentation des résultats de classification . 1
3 Références normatives . 1
4 Termes, définitions et termes abrégés . 2
4.1 Termes et définitions . 2
4.2 Termes abrégés . 4
5 Systèmes de classification . 5
5.1 Concept . 5
5.2 Classification et légende . 7
5.3 Systèmes hiérarchiques contre systèmes non hiérarchiques . 8
5.4 Systèmes de classification a priori et a posteriori . 8
5.5 Structure de données classifiées . 9
5.6 Ensemble de données de classification .13
6 Gestion des classificateurs .14
6.1 Généralités .14
6.2 Registre de dictionnaire de concepts pour un principe de classification .15
6.3 Gestion des classificateurs par l’enregistrement .15
6.4 Structure de registres .16
Annexe A (normative) Suite d’essais abstraits .25
Annexe B (informative) Systèmes de classification a priori et a posteriori.27
Bibliographie .31
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ISO 19144-1:2009(F)
Avant-propos
L’ISO (Organisation internationale de normalisation) est une fédération mondiale d’organismes nationaux de
normalisation (comités membres de l’ISO). L’élaboration des Normes internationales est en général confiée aux
comités techniques de l’ISO. Chaque comité membre intéressé par une étude a le droit de faire partie du comité
technique créé à cet effet. Les organisations internationales, gouvernementales et non gouvernementales,
en liaison avec l’ISO participent également aux travaux. L’ISO collabore étroitement avec la Commission
électrotechnique internationale (CEI) en ce qui concerne la normalisation électrotechnique.
Les Normes internationales sont rédigées conformément aux règles données dans les Directives ISO/CEI, Partie 2.
La tâche principale des comités techniques est d’élaborer les Normes internationales. Les projets de Normes
internationales adoptés par les comités techniques sont soumis aux comités membres pour vote. Leur publication
comme Normes internationales requiert l’approbation de 75 % au moins des comités membres votants.
L’attention est appelée sur le fait que certains des éléments du présent document peuvent faire l’objet de droits
de propriété intellectuelle ou de droits analogues. L’ISO ne saurait être tenue pour responsable de ne pas avoir
identifié de tels droits de propriété et averti de leur existence.
L’ISO 19144-1 a été élaborée conjointement par l’Organisation des Nations Unies pour l’Alimentation et
l’Agriculture (FAO) et le comité technique ISO/TC 211, Information géographique/Géomatique, dans le cadre
d’un accord de coopération entre les deux organisations.
L’ISO 19144 comprend les parties suivantes, présentées sous le titre général Information géographique —
Systèmes de classification:
— Partie 1: Structure de système de classification
La partie suivante est en cours d’élaboration:
— Partie 2: Métalangage de couverture du sol (LCML)
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Introduction
La présente partie de l’ISO 19144 est basée sur des publications de l’Organisation des Nations Unies pour
[1][2]
l’Alimentation et l’Agriculture (FAO) . Première d’une série de Normes internationales se rapportant aux
systèmes de classification géographique, elle définit la structure de ces systèmes, ainsi que le mécanisme de
définition et d’enregistrement de classificateurs.
Comme il existe de nombreux et divers domaines d’application possibles, il n’existe pas de système de
classification unique répondant à tous les besoins. La méthode par laquelle les classificateurs sont définis
dépend du domaine d’application. De plus, les classificateurs utilisés dans un domaine d’application particulier
peuvent ne pas être adaptés à toutes les situations rencontrées dans ce domaine d’application et pourraient
avoir à être augmentés dans le temps. Afin de faciliter l’extension de l’ensemble de classificateurs dans
un domaine d’application particulier, les classificateurs sont enregistrés dans une structure de registres
conforme à l’ISO 19135. Cela permet d’entretenir l’ensemble de classificateurs. L’utilisation du mécanisme
d’enregistrement selon l’ISO 19135 permet de définir des registres séparés pour différents ensembles de
classificateurs dans plusieurs communautés d’informations, en satisfaisant ainsi aux besoins d’application.
Cette approche permet une indépendance entre communautés d’informations, mais permet également de
développer des relations entre différents systèmes de classification permettant potentiellement la conversion,
ou la conversion partielle, de données d’un système de classification à un autre, ou la fusion de données
issues de deux sources distinctes.
Le concept de systèmes de classification est bien connu dans la communauté de l’information géographique.
Un système de classification peut être utilisé pour subdiviser une zone géographique en petites unités, chacune
portant un identifiant qui décrit son type. Les résultats peuvent alors être représentés sous forme d’une couverture
discrète comme décrit dans l’ISO 19123. Nombre de ces systèmes de classification peuvent être définis pour
traiter toute zone géographique. Différents domaines d’application et différentes communautés d’informations
peuvent définir leurs propres systèmes de classification. Cependant, si le système de classification est défini
d’une manière compatible, l’interaction entre différentes communautés d’informations devient possible. En
outre, dans un domaine d’application particulier, il est souhaitable d’avoir peu de systèmes de classification
bien établis et que ceux-ci soient normalisés au sein de communautés d’informations.
La présente partie de l’ISO 19144 décrit la structure commune, alors que les parties suivantes permettront la
normalisation de systèmes de classification spécifiques.
Une couverture est une fonction qui assigne des valeurs à partir de sa plage à toute position directe dans
son domaine spatial, temporel ou spatio-temporel. Une couverture discrète est une fonction qui assigne les
mêmes valeurs d’attributs d’entités à chaque position directe à l’intérieur d’un objet spatial, temporel ou bien
spatio-temporel unique dans son domaine. Le domaine est une zone couverte par la fonction de couverture
et la couverture discrète divise la zone en un ensemble d’objets spatiaux, temporels ou spatio-temporels.
La géométrie de la couverture discrète utilisée pour représenter les résultats de l’application d’un système
de classification peut être de tout type de couverture discrète — par exemple un ensemble de polygones
assemblés comme un puzzle, un ensemble de cellules de grille ou un ensemble de points ou de courbes.
Un système de classification est constitué d’un ensemble de classificateurs. Ces classificateurs peuvent être
définis de façon algorithmique ou être établis selon un ensemble de définitions du système de classification.
Les classificateurs dépendent de la zone d’application et sont ou seront définis dans les autres parties
de l’ISO 19144 ou dans d’autres normes ou publications. Un registre permet d’entretenir un ensemble de
classificateurs pour un domaine d’application particulier. Un objet spatial, temporel ou spatio-temporel défini
en termes d’ensemble de classificateurs est un objet classifié.
Les entités géographiques conventionnelles et les objets classifiés ont un point commun. Une entité est définie
dans l’ISO 19101 comme une abstraction de phénomènes du monde réel. Un bâtiment est un exemple de
classe d’entité et un bâtiment particulier, par exemple le bâtiment de l’ONU à New York, est une instance
de classe d’entité. Les entités géographiques conventionnelles sont des unités atomiques assemblées pour
construire un type d’ensemble de données d’informations géographiques.
Un système de classification fonctionne de la manière opposée, de manière descendante, en décomposant
successivement le tout en une zone de couverture. Les objets classifiés sont des entités, en ce qu’elles sont
une abstraction de phénomènes du monde réel, mais les objets classifiés ne sont pas atomiques, car ils sont
nécessairement liés les uns aux autres par les classificateurs qui décomposent le tout. Dans un exemple
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ISO 19144-1:2009(F)
simple de système de classification, la Terre en tant que tout peut être recouverte par de la «terre» ou de
«l’eau» et deux classificateurs peuvent être définis en fractionnant la plage d’attributs en deux, en identifiant
les objets comme étant de la terre ou de l’eau. Toute zone particulière de la Terre, correspondant à un objet
classifié, serait de type «terre» ou «eau».
L’ISO 19135 spécifie qu’une norme technique est nécessaire pour définir les classes d’éléments dans tout
registre conforme. La présente partie de l’ISO 19144 définit des schémas pour des registres conformes à
l’ISO 19135 et sert de norme technique pour définir les classes d’éléments nécessaires pour l’enregistrement
de classificateurs. Elle établit un ensemble de règles pour spécifier des définitions pouvant être utilisées dans
un contexte particulier afin d’établir des objets classifiés.
Les registres de classificateurs peuvent servir de sources de référence pour des registres similaires établis par
d’autres communautés d’informations géographiques dans le cadre d’un système de référencement croisé. Le
référencement croisé entre des éléments respectifs dans des registres de classificateurs peut être difficile dans
les cas où la structure des registres diffère d’une communauté d’informations à l’autre. La présente partie de
l’ISO 19144 peut servir de guide pour différentes communautés d’informations concernant le développement
de registres compatibles pouvant prendre en charge un système de référencement croisé de classificateurs.
La structure d’un système de classification ainsi que le mécanisme de définition et d’enregistrement de
classificateurs définis dans la présente partie de l’ISO 19144 sont généraux et peuvent être appliqués à de
nombreux systèmes de classifications, définis par différentes communautés d’information, comprenant le sol,
le relief, la végétation, l’urbanisation et les systèmes visant à analyser la biodiversité et les changements
climatiques. L’utilisation du présent document permettra de décrire la relation entre différents systèmes de
classification.
vi © ISO 2009 – Tous droits réservés
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NORME INTERNATIONALE ISO 19144-1:2009(F)
Information géographique — Systèmes de classification —
Partie 1:
Structure de système de classification
1 Domaine d’application
La présente partie de l’ISO 19144 établit la structure d’un système de classification d’informations géographiques,
ainsi que le mécanisme de définition et d’enregistrement des classificateurs pour un tel système. Elle spécifie
l’utilisation de couvertures discrètes pour représenter le résultat de l’application du système de classification à une
zone particulière et définit la structure technique d’un registre de classificateurs, conformément à l’ISO 19135.
La structure peut être utilisée pour développer des systèmes de classification spécifiques traitant de domaines
d’application particuliers, spécifiés dans d’autres parties de l’ISO 19144.
2 Conformité
2.1 Classes
Trois classes de conformité sont identifiées dans la présente partie de l’ISO 19144.
2.2 Conformité d’un système de classification
Tout système de classification, pour lequel la conformité à la présente partie de l’ISO 19144 est revendiquée,
doit être conforme à l’Annexe A (voir en A.2.).
2.3 Conformité d’un registre de classificateurs
Tout registre de classificateurs, pour lequel la conformité à la présente partie de l’ISO 19144 est revendiquée,
doit être conforme à l’Annexe A (voir en A.3.) et à l’ISO 19135:2005, A.1.
2.4 Représentation des résultats de classification
Toute légende de classificateurs, pour laquelle la conformité à la présente partie de l’ISO 19144 est revendiquée,
doit être conforme à l’Annexe A (voir en A.4).
3 Références normatives
Les documents de référence suivants sont indispensables à l’application du présent document. Pour les
références datées, seule l’édition citée s’applique. Pour les références non datées, la dernière édition du
document de référence s’applique (y compris les éventuels amendements).
ISO/TS 19103:2005, Information géographique — Langage de schéma conceptuel
ISO 19110:2005, Information géographique — Méthodologie de catalogage des entités
ISO 19115, Information géographique — Métadonnées
ISO 19123, Information géographique — Schéma de la géométrie et des fonctions de couverture
ISO 19135:2005, Information géographique — Procédures pour l’enregistrement d’éléments
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ISO 19144-1:2009(F)
4 Termes, définitions et termes abrégés
Pour les besoins du présent document, les termes, définitions et termes abrégés suivants s’appliquent.
4.1 Termes et définitions
4.1.1
classification a posteriori
principe de classification (4.1.4) basé sur la définition de classes après un regroupement des échantillons
recueillis sur le terrain
NOTE 1 Extrait du Système de classification de l’occupation du sol (LCCS, Land Cover Classification System),
version 2, de la FAO (voir la Référence [2]).
NOTE 2 Voir l’Annexe B pour un examen de cette classification et de la classification a priori (4.1.2).
4.1.2
classification a priori
principe de classification (4.1.4) structuré de façon que les classes soient des conceptualisations abstraites
des types se produisant effectivement
NOTE 1 Extrait du Système de classification de l’occupation du sol (LCCS, Land Cover Classification System),
version 2, de la FAO (voir la Référence [2]).
NOTE 2 Cette approche est basée sur la définition de classes avant que toute collecte de données ne se déroule.
NOTE 3 Voir l’Annexe B pour un examen de cette classification et de la classification a posteriori (4.1.1).
4.1.3
objet classifié
objet spatial, temporel ou spatio-temporel affecté à une classe de légende (4.1.16) spécifique
4.1.4
classification
représentation abstraite à l’aide de classificateurs (4.1.6) de phénomènes survenant dans le monde réel
4.1.5
système de classification
système destiné à assigner des objets à des classes
4.1.6
classificateur
définition utilisée afin d’assigner des objets à des classes de légendes (4.1.16)
NOTE Les classificateurs peuvent être définis de façon algorithmique ou conformément à un ensemble de règles
propres à un système de classification (4.1.5).
4.1.7
couverture
entité (4.1.10) qui agit comme une fonction en assignant des valeurs à partir de sa plage (4.1.17) à toute
position directe dans son domaine (4.1.9) spatial, temporel ou spatio-temporel
[ISO 19123:2005]
EXEMPLE Image matricielle, couverture de polygones, modèle numérique d’altitude.
NOTE Une couverture est une entité qui prend des valeurs multiples selon le type d’attribut, où chaque position
directe dans la représentation géométrique de la caractéristique a une valeur unique pour chaque type d’attribut.
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ISO 19144-1:2009(F)
4.1.8
couverture discrète
couverture (4.1.7) qui assigne les mêmes valeurs d’attribut d’une entité (4.1.11) à chaque position directe à
l’intérieur d’un objet spatial, temporel ou bien spatio-temporel unique dans son domaine (4.1.9)
[ISO 19123:2005]
NOTE Le domaine d’une couverture discrète se compose d’un ensemble fini d’objets spatiaux, temporels ou
spatio-temporels.
4.1.9
domaine
ensemble bien défini
[ISO/TS 19103:2005]
NOTE Les domaines permettent de définir le domaine et la plage (4.1.17) des opérateurs et des fonctions.
4.1.10
entité
abstraction de phénomènes du monde réel
[ISO 19101:2002]
EXEMPLE Le phénomène «Tour Eiffel» peut être classifié avec d’autres phénomènes similaires dans un type
d’entité «tour».
NOTE Une entité peut se présenter comme un type ou comme une instance. Dans la présente partie de l’ISO 19144,
type est désigné, sauf spécification contraire.
4.1.11
attribut d’une entité
propriété d’une entité (4.1.10)
[ISO 19101:2002]
4.1.12
dictionnaire de concepts d’entités
dictionnaire contenant des définitions de concepts ainsi que les informations de description associées les
concernant, pouvant être spécifiés en détail dans un catalogue d’entités (4.1.10)
1)
[ISO 19126:— ]
4.1.13
identifiant
séquence de caractères linguistiquement indépendante capable d’identifier de manière exclusive et continue
ce à quoi elle est associée
[ISO 19135:2005]
4.1.14
classe d’éléments
ensemble d’éléments ayant des propriétés communes
NOTE 1 Adapté de l’ISO 19135:2005.
NOTE 2 La «classe» est utilisée dans ce contexte afin de faire référence à un ensemble d’instances et non au concept
issu de cet ensemble d’instances.
1) À paraître.
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ISO 19144-1:2009(F)
4.1.15
légende
application d’une classification (4.1.4) au sein d’une zone spécifique à l’aide d’une échelle de mise en
correspondance définie et d’un ensemble de données spécifique
NOTE Extrait de la Classification de l’occupation du sol (LCCS, Land Cover Classification System), version 2, de la
FAO (voir la Référence [2]).
4.1.16
classe de légende
classe résultante de l’application d’un processus de classification (4.1.4)
NOTE Le résultat d’un processus de classification est appelé classe de légende dans la présente partie de l’ISO 19144
afin d’éviter toute confusion avec le terme «classe» utilisé dans la modélisation UML.
4.1.17
plage
〈couverture〉 ensemble de valeurs d’attributs d’une entité (4.1.11) associé par une fonction aux éléments du
domaine (4.1.9) d’une couverture (4.1.7)
[ISO 19123:2005]
4.1.18
registre
ensemble de fichiers contenant des identifiants (4.1.13) attribués à des éléments et des descriptions qui leur
sont associées
NOTE Adapté de l’ISO 19135:2005.
4.1.19
bureau d’enregistrement
système d’information dans lequel un registre (4.1.18) est mis à jour
[ISO 19135:2005]
4.1.20
norme technique
norme contenant les définitions des classes d’éléments (4.1.14) requérant un enregistrement
NOTE Adapté de l’ISO 19135:2005.
4.1.21
géométrie vectorielle
représentation d’une géométrie par l’utilisation de primitives géométriques constructives
[ISO 19107:2003]
4.2 Termes abrégés
4.2.1 Généralités
CRS Système de coordonnées de référence (Coordinate Reference System)
LCCS Système de classification d’occupation du sol (Land Cover Classification System)
UML Langage de modélisation unifié (Unified Modelling Language)
4.2.2 Notation
Le schéma conceptuel spécifié dans la présente partie de l’ISO 19144 est décrit à l’aide du Langage de
modélisation unifié (UML, Unified Modelling Language), en suivant les lignes directrices de l’ISO/TS 19103.
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ISO 19144-1:2009(F)
Plusieurs éléments de modèles utilisés dans ce schéma sont définis dans d’autres normes de la série ISO 19100.
2)
Par convention, dans cette suite de Normes internationales, les noms des classes UML , à l’exception des
classes relatives aux types de données de base, comportent un préfixe à deux lettres qui identifie la Norme
internationale et le «paquetage» UML dans lequel la classe est définie.
Les classes UML définies dans la présente partie de l’ISO 19144 ont le préfixe à deux lettres «CL».
Le Tableau 1 répertorie les autres Normes internationales et les «paquetages» dans lesquels les classes UML
utilisées dans la présente partie de l’ISO 19144 ont été définies.
Tableau 1 — Sources des classes UML définies en dehors du présent document
Préfixe Norme internationale «Paquetage»
CV ISO 19123 Coverage core et couvertures discrètes
DS ISO 19115 Informations d’application de métadonnées
GF ISO 19109 Modèle sémantique
GM ISO 19107 Géométrie
MD ISO 19115 Informations d’ensemble d’entités de métadonnées
MI ISO 19115-2 Images d’ensemble d’entités de métadonnées
RE ISO 19135 Procédures d’enregistrement
SC ISO 19111 Système de références spatiales par coordonnées
TM ISO 19108 Objets temporels
5 Systèmes de classification
5.1 Concept
Une couverture discrète assigne le même attribut d’entité à chaque position directe à l’intérieur d’un objet
géométrique unique dans son domaine spatio-temporel. Le domaine spatio-temporel comprend un ensemble
d’objets géométriques qui forment la couverture.
EXEMPLE 1 La couverture discrète de zones postales dans un pays: chaque zone a un code différent et il n’est pas
possible d’interpoler ces codes. Cependant, il pourrait exister une relation de haut niveau entre les codes. Le petit pays
de Monaco est divisé en cinq quartiers: «Moneghetti», «La Condamine», «Fontvieille», «Monaco-Ville» et «Monte-Carlo».
Ces juridictions politiques couvrent complètement la surface du pays. La superficie de Monaco peut être représentée
par une couverture discrète ayant cinq objets spatiaux, où chaque objet présente la géométrie de polygone. La valeur
d’attribut de chaque objet spatial est le nom de la juridiction politique. Voir Figure 1.
2) Il existe une confusion potentielle entre l’usage du terme «classe» utilisé dans le langage UML, le terme «classe»
utilisé dans un principe de classification, et le terme «classe d’élément» utilisé dans les procédures d’enregistrement. Le
terme classe, qui est utilisé dans un principe de classification, est appelé classe de légende dans la présente partie de
l’ISO 19144.
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ISO 19144-1:2009(F)
Moneghetti La Condamine
Monte-Carlo
Monaco
Fontvieille Monaco-Ville
Figure 1 — Exemple de couverture discrète avec une géométrie de polygones
La géométrie des objets spatiaux associés à une couverture discrète peut également être représentée par des
cellules de grille dans une structure de grille. Chacune des cellules de grille peut porter un attribut.
EXEMPLE 2 Une couverture discrète ayant une géométrie de grille de la même superficie que celle utilisée dans
l’exemple précédent. Voir Figure 2. La légende de la figure identifie les instances des valeurs d’attributs qui existent
effectivement dans les données.
Monte-Carlo
Monaco
Moneghetti
Monaco-Ville
Fontvieille
La Condamine
Figure 2 — Exemple de couverture discrète avec une géométrie de grille
NOTE Les couvertures discrètes illustrées par les exemples ci-dessus sont simples car un seul attribut relativement
simple a été utilisé. Cependant, dans la réalité, les attributs pour chacun des objets spatiaux d’une couverture peuvent être
très complexes. Afin de décrire l’occupation du sol, il est nécessaire d’intégrer un grand nombre de paramètres descriptifs
associés au sol, à la biologie et à la densité dans un système de classification d’occupation du sol complet. Un tel système
de classification dépend bien sûr de la zone d’application. Un océanographe aura un système de classification différent
de celui d’un météorologue. Les systèmes de classification peuvent grandement varier dans des zones d’application
différentes mais, pour des zones d’application similaires, quelques points communs doivent exister afin de pouvoir utiliser
ensemble des données issues de sources différentes.
6 © ISO 2009 – Tous droits réservés
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ISO 19144-1:2009(F)
Un système de classification permet de définir des classificateurs afin de fractionner la plage d’attributs d’une
couverture discrète pour établir des objets classifiés.
5.2 Classification et légende
La classification est une représentation abstraite de phénomènes du monde réel (c’est-à-dire la situation sur
le terrain) utilisant des classificateurs. Une classification est un cadre systématique accompagné des noms
des classes et des définitions utilisées pour les distinguer et de la relation entre des classes. Une classification
implique donc nécessairement la définition de frontières entre les classes qui doivent être claires et basées sur
des critères objectifs.
Un système de classification doit être
— indépendant de l’échelle, ce qui signifie que les classes à tous les niveaux du système doivent être
applicables à n’importe quelle échelle ou niveau de détail et
— indépendant de la source, ce qui implique qu’il est indépendant des moyens utilisés pour recueillir des
informations.
NOTE 1 L’indépendance vis-à-vis de l’échelle et l’indépendance de la source existent dans le cas général d’un système
de classification. Lorsque le système est appliqué à des données réelles, c’est-à-dire lorsqu’une légende est créée, les
limites des données en termes d’échelle et de source peuvent créer des restrictions pour la légende.
Une légende est l’application d’une classification dans une zone spécifique en utilisant une échelle de mise en
correspondance définie et un ensemble de données spécifique. Ainsi, une légende peut ne contenir qu’une
proportion, ou sous-ensemble, de toutes les classes possibles de la classification.
Une légende doit être
— dépendante de l’échelle et
— dépendante de la source.
EXEMPLE 1 Dépendance vis-à-vis de l’échelle: certains éléments peuvent être trop petits pour être délimités
indépendamment lorsqu’ils sont recueil
...
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.Geografske informacije - Klasifikacijski sistemi - 1. del: Struktura klasifikacijskega sistemaInformation géographique - Systèmes de classification - Partie 1: Structure de système de classificationGeographic information - Classification systems - Part 1: Classification system structure35.240.70Uporabniške rešitve IT v znanostiIT applications in scienceICS:Ta slovenski standard je istoveten z:ISO/FDIS 19144-1oSIST ISO/FDIS 19144-1:2009en01-julij-2009oSIST ISO/FDIS 19144-1:2009SLOVENSKI
STANDARD
oSIST ISO/FDIS 19144-1:2009
Please see the administrative notes on page iii
RECIPIENTS OF THIS DRAFT ARE INVITED TOSUBMIT, WITH THEIR COMMENTS, NOTIFICATION OF ANY RELEVANT PATENT RIGHTS OF WHICHTHEY ARE AWARE AND TO PROVIDE SUPPORT-ING DOCUMENTATION. IN ADDITION TO THEIR EVALUATION AS BEING ACCEPTABLE FOR INDUSTRIAL, TECHNO-LOGICAL, COMMERCIAL AND USER PURPOSES,DRAFT INTERNATIONAL STANDARDS MAY ONOCCASION HAVE TO BE CONSIDERED IN THELIGHT OF THEIR POTENTIAL TO BECOME STAN-DARDS TO WHICH REFERENCE MAY BE MADE IN NATIONAL REGULATIONS.
Reference numberISO/FDIS 19144-1:2009(E)© ISO 2009 FINAL DRAFT ISO/TC 211 Secretariat: SN Voting begins on: 2009-05-20 Voting terminates on: 2009-07-20
INTERNATIONAL STANDARD ISO/FDIS19144-1Geographic information — Classification systems — Part 1: Classification system structure Information géographique — Systèmes de classification — Partie 1: Structure de système de classification
oSIST ISO/FDIS 19144-1:2009
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ISO/FDIS 19144-1:2009(E) © ISO 2009 – All rights reserved iiiIn accordance with the provisions of Council Resolution 15/1993, this document is circulated in the English language only.
oSIST ISO/FDIS 19144-1:2009
ISO/FDIS 19144-1:2009(E) iv © ISO 2009 – All rights reserved Contents Page Foreword.v Introduction.vi 1 Scope.1 2 Conformance.1 2.1 Classes.1 2.2 Conformance of a classification system.1 2.3 Conformance of a register of classifiers.1 2.4 Representation of classification results.1 3 Normative references.1 4 Terms, definitions and abbreviated terms.2 4.1 Terms and definitions.2 4.2 Abbreviated terms.4 5 Classification systems.5 5.1 Concept.5 5.2 Classification and legend.7 5.3 Hierarchical versus non-hierarchical systems.8 5.4 A priori and a posteriori classification systems.8 5.5 Structure of classified data.9 5.6 A classification data set.13 6 Management of classifiers.14 6.1 General.14 6.2 Concept dictionary register for a classification scheme.15 6.3 Management of classifiers through registration.15 6.4 Register structure.15 Annex A (normative)
Abstract test suite.24 Annex B (informative)
A priori and a posteriori classification systems.26 Bibliography.30
oSIST ISO/FDIS 19144-1:2009
ISO/FDIS 19144-1:2009(E) © ISO 2009 – All rights reserved vForeword ISO (the International Organization for Standardization) is a worldwide federation of national standards bodies (ISO member bodies). The work of preparing International Standards is normally carried out through ISO technical committees. Each member body interested in a subject for which a technical committee has been established has the right to be represented on that committee. International organizations, governmental and non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization. International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2. The main task of technical committees is to prepare International Standards. Draft International Standards adopted by the technical committees are circulated to the member bodies for voting. Publication as an International Standard requires approval by at least 75 % of the member bodies casting a vote. Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. ISO shall not be held responsible for identifying any or all such patent rights. ISO 19144-1 was prepared jointly by the Food and Agriculture Organization (FAO) of the United Nations and Technical Committee ISO/TC 211, Geographic information/Geomatics under a cooperative agreement between the two organizations. ISO 19144 consists of the following parts, under the general title Geographic information — Classification systems: ⎯ Part 1: Classification system structure The following parts are under preparation: ⎯ Part 2: Land cover classification system (LCCS) oSIST ISO/FDIS 19144-1:2009
ISO/FDIS 19144-1:2009(E) vi © ISO 2009 – All rights reserved Introduction This part of ISO 19144 is based on publications of the Food and Agriculture Organization (FAO) of the United Nations [1], [2]. The first in a series of International Standards related to geographic classification systems, it defines the structure of such systems, together with the mechanism for defining and registering classifiers. Since there are many different possible application areas, there is no single classification system that will serve all needs. The method by which classifiers are defined depends upon the application area. In addition, the classifiers used within a particular application area might not be adequate for all situations encountered within that application area and could need to be augmented over time. To facilitate extension of the set of classifiers in a particular application area, classifiers are registered in a register structure compliant with ISO 19135. This allows the set of classifiers to be maintained. The use of the ISO 19135 registration mechanism allows for separate registers to be defined for different sets of classifiers within multiple information communities, thereby satisfying application needs. This approach allows for independence between information communities, but also allows relationships to be developed between different classification systems that potentially allow the conversion, or partial conversion, of data from one classification system to another, or the fusion of data from two separate sources. The concept of classification systems is well known in the geographic information community. A classification system can be used to subdivide any geographic area into small units, each of which carries an identifier that describes its type. The results can then be represented as a discrete coverage as described in ISO 19123. Many such classification systems can be defined to address any geographic area. Different application areas and different information communities can define their own classification systems. However, if the classification system is defined in a compatible way, interaction between different information communities becomes possible. In addition, in a particular application area, it is desirable that there be a few well-established classification systems, and that these themselves be standardized within information communities. This part of ISO 19144 describes the common structure, while subsequent parts will allow for the standardization of specific classification systems. A coverage is a function that returns values from its range for any direct position within its spatial, temporal or spatiotemporal domain. A discrete coverage is a function that returns the same feature attribute values for every direct position within any single spatial object, temporal object or spatiotemporal object in its domain. The domain is an area covered by the coverage function, and the discrete coverage breaks that area down into a set of spatial, temporal or spatiotemporal objects. The geometry of the discrete coverage used to represent the results of applying a classification system can be any type of discrete coverage — for example, a set of polygons fitted together like a jig-saw puzzle, a set of grid cells, or a set of points or curves. A classification system consists of a set of classifiers. These classifiers may be algorithmically defined, or established according to a set of classification system definitions. The classifiers are application-area-dependent and are or will be defined in the other parts of ISO 19144 or other standards or publications. A register allows for the maintenance of a set of classifiers for a particular application area. A spatial, temporal or spatiotemporal object defined in terms of a set of classifiers is a classified object. There is a commonality between conventional geographic features and classified objects. A feature is defined in ISO 19101 as an abstraction of real world phenomena. An example of a class of feature is a building, and a particular building, e.g. the UN building in New York, is an instance of a feature class. Conventional geographic features are atomic units that are assembled to build one type of geographic information data set. A classification system works in the opposite manner, from the top down, by successively decomposing the whole within a coverage area. Classified objects are features, in that they are an abstraction of a real world phenomena, but classified objects are not atomic, because they are necessarily related to each other by the classifiers that decompose the whole. In a simple example of a classification system, the earth as a whole can be covered by either “land” or “water”, and two classifiers can be defined partitioning the attribute range into oSIST ISO/FDIS 19144-1:2009
ISO/FDIS 19144-1:2009(E) © ISO 2009 – All rights reserved viitwo, identifying objects as being either land or water. Any particular area on the earth, corresponding to a classified object, would be of type “land” or “water”. ISO 19135 specifies that a technical standard be required to define the item classes in any conformant register. This part of ISO 19144 defines schemas for registers conformant to ISO 19135 and serves as the technical standard that defines the item classes required for the registration of classifiers. It establishes a set of rules for specifying definitions that can be used in a particular context to establish classified objects. Registers of classifiers can serve as sources of reference for similar registers established by other geographic information communities as part of a system of cross-referencing. Cross-referencing between respective items in registers of classifiers might be difficult in cases where the structure of registers differs between information communities. This part of ISO 19144 can serve as a guide for different information communities for the development of compatible registers that can support a system of classifier cross-referencing. The structure of a classification system together with the mechanism of defining and registering classifiers defined in this part of ISO 19144 is general and can be applied to many different information-community-defined classification systems, including soil, landform, vegetation, urbanization and systems for understanding biodiversity and climate change. The use of this document will allow the relationship between different classification systems to be described.
oSIST ISO/FDIS 19144-1:2009
oSIST ISO/FDIS 19144-1:2009
FINAL DRAFT INTERNATIONAL STANDARD ISO/FDIS 19144-1:2009(E) © ISO 2009 – All rights reserved 1Geographic information — Classification systems — Part 1: Classification system structure 1 Scope This part of ISO 19144 establishes the structure of a geographic information classification system, together with the mechanism for defining and registering the classifiers for such a system. It specifies the use of discrete coverages to represent the result of applying the classification system to a particular area and defines the technical structure of a register of classifiers in accordance with ISO 19135. The structure can be used to develop specific classification systems that address particular application areas, specified in other parts of ISO 19144. 2 Conformance 2.1 Classes Three conformance classes are identified in this part of ISO 19144. 2.2 Conformance of a classification system Any classification system for which conformance to this part of ISO 19144 is claimed shall be in accordance with Annex A (see A.2). 2.3 Conformance of a register of classifiers Any register of classifiers for which conformance to this part of ISO 19144 is claimed shall be in accordance with Annex A (see A.3) and ISO 19135:2005, A.1. 2.4 Representation of classification results Any legend of classifiers for which conformance to this part of ISO 19144 is claimed shall be in accordance with Annex A (see A.4). 3 Normative references The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. ISO/TS 19103:2005, Geographic information — Conceptual schema language ISO 19110:2005, Geographic information — Methodology for feature cataloguing ISO 19115, Geographic information — Metadata oSIST ISO/FDIS 19144-1:2009
ISO/FDIS 19144-1:2009(E) 2 © ISO 2009 – All rights reserved ISO 19123, Geographic information — Schema for coverage geometry and functions ISO 19135:2005, Geographic information — Procedures for item registration 4 Terms, definitions and abbreviated terms For the purposes of this document, the following terms, definitions and abbreviated terms apply. 4.1 Terms and definitions 4.1.1 a posteriori classification classification (4.1.4) scheme based upon definition of classes after clustering the field samples collected NOTE 1 Taken from FAO LCCS version 2 (see Reference [2]). NOTE 2 See Annex B for an examination of this and a priori classification (4.1.2). 4.1.2 a priori classification classification (4.1.4) scheme structured so that the classes are abstract conceptualizations of the types actually occurring NOTE 1 Taken from FAO LCCS version 2 (see Reference [2]). NOTE 2 The approach is based upon the definition of classes before any data collection actually takes place. NOTE 3 See Annex B for an examination of this and a posteriori classification (4.1.1). 4.1.3 classified object spatial object, temporal object or spatiotemporal object assigned to a specific legend class (4.1.16) 4.1.4 classification abstract representation of real world phenomena using classifiers (4.1.6) 4.1.5 classification system system for assigning objects to classes 4.1.6 classifier definition used to assign objects to legend classes (4.1.16) NOTE Classifiers can be defined algorithmically or according to a set of classification system (4.1.5) specific rules. 4.1.7 coverage feature (4.1.10) that acts as a function to return values from its range (4.1.17) for any direct position within its spatial, temporal or spatiotemporal domain (4.1.9) [ISO 19123:2005] EXAMPLE Raster image, polygon overlay, digital elevation matrix. NOTE A coverage is a feature that has multiple values for each attribute type, where each direct position within the geometric representation of the feature has a single value for each attribute type. oSIST ISO/FDIS 19144-1:2009
ISO/FDIS 19144-1:2009(E) © ISO 2009 – All rights reserved 34.1.8 discrete coverage coverage (4.1.7) that returns the same feature attribute (4.1.11) values for every direct position within any single spatial object, temporal object, or spatiotemporal object in its domain (4.1.9) [ISO 19123:2005] NOTE The domain of a discrete coverage consists of a finite set of spatial, temporal, or spatiotemporal objects. 4.1.9 domain well-defined set [ISO/TS 19103:2005] NOTE Domains are used to define the domain and range (4.1.17) of operators and functions. 4.1.10 feature abstraction of real world phenomena [ISO 19101:2002] EXAMPLE The phenomenon “Eiffel Tower” can be classified with other similar phenomena into a feature type “tower”. NOTE A feature can occur as a type or an instance. In this part of ISO 19144, type is meant unless otherwise specified. 4.1.11 feature attribute characteristic of a feature (4.1.10) [ISO 19101:2002] 4.1.12 feature concept dictionary dictionary that contains definitions of, and related descriptive information about, concepts that may be specified in detail in a feature (4.1.10) catalogue 4.1.13 identifier linguistically independent sequence of characters capable of uniquely and permanently identifying that with which it is associated [ISO 19135:2005] 4.1.14 item class set of items with common properties [ISO 19135:2005] NOTE “Class” is used in this context to refer to a set of instances, not the concept abstracted from that set of instances. 4.1.15 legend application of a classification (4.1.4) in a specific area using a defined mapping scale and specific data set oSIST ISO/FDIS 19144-1:2009
ISO/FDIS 19144-1:2009(E) 4 © ISO 2009 – All rights reserved 4.1.16 legend class class resultant from the application of a classification (4.1.4) process NOTE The result of a classification process is termed legend class in this part of ISO 19144 in order to avoid confusion with the term “class” as used in UML modelling. 4.1.17 range 〈coverage〉 set of feature attribute (4.1.11) values associated by a function with the elements of the
domain (4.1.9) of a coverage (4.1.7) [ISO 19123:2005] 4.1.18 register set of files containing identifiers (4.1.13) assigned to items with descriptions of the associated items [ISO 19135:2005] 4.1.19 registry information system on which a register (4.1.18) is maintained [ISO 19135:2005] 4.1.20 technical standard standard containing the definitions of item classes (4.1.14) requiring registration [ISO 19135:2005] 4.1.21 vector geometry representation of geometry through the use of constructive geometric primitives [ISO 19107:2003] 4.2 Abbreviated terms 4.2.1 General CRS coordinate reference system LCCS land cover classification system UML unified modelling language 4.2.2 Notation The conceptual schema specified in this part of ISO 19144 is described using the unified modelling language (UML), following the guidance of ISO/TS 19103. oSIST ISO/FDIS 19144-1:2009
ISO/FDIS 19144-1:2009(E) © ISO 2009 – All rights reserved 5Several model elements used in this schema are defined in other standards in the ISO 19100 series. By convention within this suite of International Standards, names of UML classes1), with the exception of basic data type classes, include a two-letter prefix that identifies the International Standard and the UML package in which the class is defined. UML classes defined in this part of ISO 19144 have the two-letter prefix “CL”. Table 1 lists the other International Standards and the packages in which UML classes used in this part of ISO 19144 have been defined. Table 1 — Sources of externally defined UML classes Prefix International Standard Package CV ISO 19123 Coverage core and discrete coverages DS ISO 19115 Metadata application information GF ISO 19109 General feature model GM ISO 19107 Geometry root MD ISO 19115 Metadata entity set information MI ISO 19115-2 Metadata entity set imagery RE ISO 19135 Procedures for registration SC ISO 19111 Spatial referencing by coordinates TM ISO 19108 Temporal objects
5 Classification systems 5.1 Concept A discrete coverage returns the same feature attribute for every direct position within any single geometric object in its spatiotemporal domain. The spatiotemporal domain consists of a set of geometric objects that together form the coverage. EXAMPLE 1 The discrete coverage of postal zones within a country: each zone has a different code and it is not possible to interpolate between these codes. Nevertheless, there could be a high level relationship between the codes. The small country of Monaco is divided into five quartiers: “Moneghetti”, “La Condamine”, “Fontvieille”, “Monaco-Ville” and “Monte-Carlo”. These political jurisdictions completely cover the area of the country. The area of Monaco can be represented as a discrete coverage with five spatial objects where each object has the geometry of a polygon. The attribute value for each spatial object is the name of the political jurisdiction. See Figure 1.
1) There is potential confusion between the use of the term “class” as used in UML, “class” as used in a classification scheme and “item class” as used in the procedures for registration. Class as used in a classification scheme is termed legend class in this part of ISO 19144. oSIST ISO/FDIS 19144-1:2009
ISO/FDIS 19144-1:2009(E) 6 © ISO 2009 – All rights reserved MoneghettiLa CondamineMonte-CarloFontvieilleMonaco-VilleMonaco Figure 1 — Example of discrete coverage with polygon geometry The geometry of the spatial objects associated with a discrete coverage can also be grid cells within a grid structure. Each of the grid cells may carry an attribute. EXAMPLE 2 A discrete coverage with grid geometry of the same area as used in the previous example. See Figure 2. The figure legend identifies the instances of the attribute values that actually exist in the data.
MoneghettiLa CondamineMonte-CarloFontvieilleMonaco-VilleMonaco Figure 2 — Example of discrete coverage with grid geometry NOTE The discrete coverages illustrated by the above examples are simple because only one relatively simple attribute has been used. However, in reality the attributes for each of the coverage spatial objects can be very complex. In order to describe land cover it is necessary to integrate a large number of descriptive parameters related to soil, biology and density into a comprehensive land cover classification system. Such a classification system is of course application-area-dependent. An oceanographer will have a different classification system than that of a meteorologist. Classification systems can vary widely in different application areas, but for similar application areas there needs to be some commonality in order for data from different sources to be used together. oSIST ISO/FDIS 19144-1:2009
ISO/FDIS 19144-1:2009(E) © ISO 2009 – All rights reserved 7A classification system allows one to define classifiers in order to partition the attribute range of a discrete coverage to establish classified objects. 5.2 Classification and legend Classification is an abstract representation of real world phenomena (i.e. the situation in the field) using classifiers. A classification is a systematic framework with the names of the classes and the definitions used to distinguish them, and the relation between classes. Classification thus necessarily involves definition of class boundaries that must be clear and based upon objective criteria. A classification system shall be ⎯ scale independent, meaning that the classes at all levels of the system shall be applicable at any scale or level of detail, and ⎯ source independent, implying that it is independent of the means used to collect information. NOTE 1 Scale independence and source independence exist in the general case of a classification system. When the system is applied to real data, i.e. when a legend is created, the scale and source limitations of the data can create restrictions on the legend. A legend is the application of a classification in a specific area using a defined mapping scale and specific data set. Therefore, a legend may contain only a proportion, or subset, of all possible classes of the classification. A legend shall be ⎯ scale dependent, and ⎯ source dependent. EXAMPLE 1 Scale dependence: some elements might be too small to be delineated independently when collected at a particular scale. EXAMPLE 2 Source dependence: elements collected from different sources, such as an aerial photograph and a satellite false colour composite image, could be different. A legend is a selection of a set of the classifiers from all of the possible classifiers within a classification system. A legend could correspond to the classifiers that apply to a single data set or it could be applicable to a number of related data sets. NOTE 2 A legend is analogous to the set of features within a feature catalogue, which is a subset of all of the possible features within a feature concept dictionary. EXAMPLE 3 The derivation of legend classes from a classification system: when applying the reference classification system to a given geographic area with a specific data type, only a subset of the classes from the reference system will occur in the real data. This set of classes is the legend with which the mapping system will be carried out. The reference system in Figure 3 is shown as a matrix with two parameters: the height of plants, ranging from 5 m to greater than 50 m, and the percentage crown cover, ranging from less than 10 % to 100 %. The classes are numbered with a code number from 1 to 100. In this specific case, the legend will have only four reference classification classes, numbers 33, 47, 78 and 83. oSIST ISO/FDIS 19144-1:2009
ISO/FDIS 19144-1:2009(E) 8 © ISO 2009 – All rights reserved 100%10%>50 m30 m>5 m50%334778831234979899100DEFINEDGEOGRAPHICAREAReference Classification Systemgiven scale and data typemappingunitsderivedlegend
Figure 3 — Legend as application of classificatio
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