EN ISO 19123-2:2026

• Abstract:

  This document specifies an implementable, conformance-testable coverage structure based on the abstract schema for coverages defined in the ISO 19123-1 coverage fundamentals. This document defines a concrete data structure that is suitable for encoding in many formats.

• Status: Not Published
• Publication Date: 20-Oct-2026
• ICS: 35.240.70 - IT applications in science
• Technical Committee: CEN/TC 287 - Geographic Information
• Drafting Committee: CEN/TC 287 - Geographic Information
• Current Stage: 6055 - CEN Ratification completed (DOR) - Publishing
• Start Date: 09-Feb-2026
• Due Date: 12-Nov-2026
• Completion Date: 09-Feb-2026
• Ref Project: oSIST prEN ISO 19123-2:2025 - Geographic information - Schema for coverage geometry and functions - Part 2: Coverage implementation schema (ISO/DIS 19123-2:2025)

• Consolidated By: ISO 19123-2:2026 - Geographic information — Schema for coverage geometry and functions — Part 2: Coverage implementation schema
• Effective Date: 12-Feb-2026

EN ISO 19123-2:2026 is the European adoption of ISO 19123-2, published by CEN. It defines an implementable, conformance-testable coverage implementation schema for geographic information, based on the abstract coverage fundamentals in ISO 19123-1. The standard is aimed at implementers and users of coverage data models, encodings, and services who need a concrete structure that can be encoded and tested.

What does EN ISO 19123-2:2026 specify?

EN ISO 19123-2:2026 specifies a concrete coverage structure that can be implemented and checked for conformance. It turns the abstract coverage model from ISO 19123-1 into data structures that can be encoded in multiple formats.

The document is organized around a general coverage core, specialized coverage types, partitioning, and encodings. Clauses 5 to 12 cover the common structure, point clouds, grid coverages, mesh coverages, partitioning, and XML and JSON encodings.

Annex	What it covers
Annex A	Conformance test classes for the coverage classes and encoding classes
Annex B	Legacy RectifiedGridCoverage and ReferenceableGridCoverage structures, kept for backwards compatibility

What are the key requirements of EN ISO 19123-2:2026?

EN ISO 19123-2:2026 is built around a small set of structural rules that make coverage data machine-checkable. The main practical point is that each coverage must declare where values are located, how those values are organized, and which encoding class is being used.

Common coverage structure

Clause 5 defines a coverage as a domain/range structure with an identifier, a domainSet, a rangeSet, a rangeType, optional metadata, and in some cases a coverageFunction. In practice, this means a coverage is not just a list of values - it must also say where those values apply and what their internal structure means.

Requirement 3 requires the coverage structure shown in Figure 4 and Table 2. That matters because software can validate whether the required pieces are present and whether the geometry, values, and metadata are assembled in the expected way.

Requirement 4 says that, when present, coverageFunction shall follow Table 3. For grids, this gives the traversal order through the range values, so implementations can store and read multi-dimensional arrays consistently.

Requirements 5 to 8 constrain the DomainSet structure. The CRS in srsName must match the axis list, the axisLabels and uomLabels lists must have the same number of items as the CRS axes, and the dimension must agree with the CRS when present. In practice, this prevents mismatches between the coordinate system and the coordinates used in the coverage.

Coverage types and values

Requirement 2 says a coverage shall be one of MultiPointCoverage, GeneralGridCoverage, MultiCurveCoverage, MultiSurfaceCoverage, or MultiSolidCoverage. That matters because each coverage type has a different geometry model, so the implementation must choose the right one for point clouds, raster-like grids, curves, surfaces, or solids.

Requirement 22 requires one or more range values for each direct position in the domainSet, and Requirement 23 requires those values to match the declared rangeType. For a reader or implementer, this means every stored value must line up with the domain positions and the declared field structure.

Requirement 26 adds a stricter rule for GeneralGridCoverage: each direct position must have exactly one range value. This is what makes grid coverages suitable for raster data and datacubes, where each grid cell maps to one value record.

Requirement 41 states that the number of items in the RangeSet must match the number of direct positions calculated from the grid axes. That is important for array-based storage and for conformance testing, because the value count must match the grid shape.

Partitioning and encodings

Clause 11 introduces partitioning as an alternative representation based on sub-coverages or direct position/value pairs. Requirements 48 to 56 control recursion, embedding, axis compatibility, disjoint extents, and the use of null values when parts of the super-coverage are not populated. In practice, this supports mosaics, time slices, band interleaving, and other composite coverage layouts without losing structural consistency.

Clauses 12.2 and 12.3 define the XML and JSON encoding classes. Requirements 58 and 61 require validation against the XML schema or JSON Schema provided with the standard, while Requirements 60 and 61 tie JSON encoding to IETF RFC 7159. This gives implementers a clear validation path for exchanged files and service payloads.

Annex B keeps RectifiedGridCoverage and ReferenceableGridCoverage for backwards compatibility. The document states that the newer GeneralGridCoverage model is preferred, but Annex B preserves the older GML-based structures for systems that still need them.

What terms does EN ISO 19123-2:2026 define?

EN ISO 19123-2:2026 defines several terms that are central to coverage modeling.

• coverage CRS - the coordinate reference system in which a coverage expresses its domain coordinates.
• displaced grid - a grid whose points stay topologically aligned even though their geometric positions may vary.
• irregular grid - a grid where the spacing along each axis is not constant.
• partition - a separately stored coverage that becomes one component of another coverage by reference.
• regular grid - a grid with constant spacing along each axis.
• transformation grid - a grid whose direct positions are produced by a transformation algorithm not otherwise specified here.
• CIS (Coverage Implementation Schema) - the implementation-oriented coverage model defined by this standard.
• CRS (Coordinate Reference System) - the coordinate system used to express coverage positions.

Who uses EN ISO 19123-2:2026?

EN ISO 19123-2:2026 is used by people who design, store, exchange, or validate coverage data. Typical users include GIS software developers, remote sensing system integrators, web coverage service implementers, and organizations that publish rasters, point clouds, datacubes, and mesh-based datasets.

It is also relevant to quality managers and buyers who need to check whether a product supports the expected coverage type and encoding. The standard helps them verify that a system can represent coverage geometry, value structure, and conformance-testable encodings in a consistent way.

What changed in EN ISO 19123-2:2026 from the previous edition?

EN ISO 19123-2:2026 states that its grid structuring differs from the previous edition. The document moves to a more general organization based on coverage dimensions and coverage subtypes, rather than only the older grid-centric split.

The standard introduces GeneralGridCoverage as the unifying grid model and separates grid axes into index, regular, irregular, and transformation types. It also adds partitioning as a first-class alternative representation and keeps RectifiedGridCoverage and ReferenceableGridCoverage in Annex B for backwards compatibility.

Another stated change is the clearer separation between the logical coverage model and the physical encodings. That is why XML, JSON, and multipart representations are treated as encoding classes rather than being tied to one single data format.

Which standards are used with EN ISO 19123-2:2026?

EN ISO 19123-2:2026 depends on ISO 19123-1:2023, which provides the coverage fundamentals and the abstract schema that this part implements. In practice, Part 1 supplies the conceptual model that Part 2 turns into concrete data structures.

ISO 19136-1:2020 is used for Geography Markup Language (GML) fundamentals. It supports the XML-based coverage encoding and the legacy GML-based grid coverage structures retained in Annex B.

OGC 08-094r1, the OGC SWE Common Data Model Encoding Standard, supplies the DataRecord model used for rangeType. That matters because the coverage range is not just a value list - its structure and semantics are defined through SWE Common.

What does the EN ISO 19123-2:2026 document contain?

EN ISO 19123-2:2026 contains UML package diagrams, textual requirements classes, and conformance rules for coverage structures. It also includes XML schema definitions, JSON Schema definitions, and example coverage files for the supported encodings.

Annex A provides the abstract conformance test suite, so implementers can check whether a product satisfies the relevant requirements. Annex B provides the older GML-based grid coverage models, including their XML schemas and examples, for systems that still rely on those legacy structures.

The document also contains tables and figures that define domain/range structure, grid traversal, partitioning rules, and grid transformation models. These are used for implementation, validation, testing, and service interoperability.

SLOVENSKI STANDARD
01-december-2025
Geografske informacije - Shema za geometrijo podatkovnega sloja in funkcije - 2.
del: Shema za implementacijo podatkovnega sloja (ISO/DIS 19123-2:2025)
Geographic information - Schema for coverage geometry and functions - Part 2:
Coverage implementation schema (ISO/DIS 19123-2:2025)
Geoinformation - Coverage Geometrie- und Funktionsschema - Teil 2: Coverage-
Implementierungsschema (ISO/DIS 19123-2:2025)
Information géographique - Schéma de la géométrie et des fonctions de couverture -
Partie 2: Schéma de la mise en place de la couverture (ISO/DIS 19123-2:2025)
Ta slovenski standard je istoveten z: prEN ISO 19123-2
ICS:
07.040 Astronomija. Geodezija. Astronomy. Geodesy.
Geografija Geography
35.240.70 Uporabniške rešitve IT v IT applications in science
znanosti
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

DRAFT
International
Standard
ISO/DIS 19123-2
ISO/TC 211
Geographic information — Schema
Secretariat: SIS
for coverage geometry and
Voting begins on:
functions —
2025-10-16
Part 2:
Voting terminates on:
2026-01-08
Coverage implementation schema
Information géographique — Schéma de la géométrie et des
fonctions de couverture —
Partie 2: Schéma de la mise en place de la couverture
ICS: 35.240.70
THIS DOCUMENT IS A DRAFT CIRCULATED
FOR COMMENTS AND APPROVAL. IT
IS THEREFORE SUBJECT TO CHANGE
AND MAY NOT BE REFERRED TO AS AN
INTERNATIONAL STANDARD UNTIL
PUBLISHED AS SUCH.
This document has not been edited by the ISO Central Secretariat.
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Reference number
ISO/DIS 19123-2:2025(en)
DRAFT
ISO/DIS 19123-2:2025(en)
International
Standard
ISO/DIS 19123-2
ISO/TC 211
Geographic information — Schema
Secretariat: SIS
for coverage geometry and
Voting begins on:
functions —
Part 2:
Voting terminates on:
Coverage implementation schema
Information géographique — Schéma de la géométrie et des
fonctions de couverture —
Partie 2: Schéma de la mise en place de la couverture
ICS: 35.240.70
THIS DOCUMENT IS A DRAFT CIRCULATED
FOR COMMENTS AND APPROVAL. IT
IS THEREFORE SUBJECT TO CHANGE
AND MAY NOT BE REFERRED TO AS AN
INTERNATIONAL STANDARD UNTIL
PUBLISHED AS SUCH.
This document has not been edited by the ISO Central Secretariat.
IN ADDITION TO THEIR EVALUATION AS
BEING ACCEPTABLE FOR INDUSTRIAL,
© ISO 2025
TECHNOLOGICAL, COMMERCIAL AND
USER PURPOSES, DRAFT INTERNATIONAL
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may
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Published in Switzerland Reference number
ISO/DIS 19123-2:2025(en)
ii
ISO/DIS 19123-2:2025(en)
Contents Page
Foreword .v
Introduction .vi
1 Scope . 1
2 Normative references . 1
3 Terms, definitions, and abbreviated terms . 1
3.1 Terms and definitions .1
3.2 Abbreviated terms .2
4 Conformance . 2
4.1 Notation .2
4.2 Interoperability and conformance testing .2
4.3 Organization .3
5 Coverages . 5
5.1 Overview .5
5.2 Terminology .6
5.3 General coverage structure.9
5.4 Domain/range based coverage structure .10
5.5 Domain Set . 12
5.5.1 Coordinate Reference System . 13
5.5.2 Direct Positions .14
5.5.3 Envelope . 15
5.6 Range type .17
5.6.1 Overview .17
5.6.2 Data description .17
5.6.3 Interpolation .18
5.7 Range Set .18
5.8 Metadata .19
6 Multi-Point Coverage . 19
7 General Grid Coverage .20
7.1 Overview . 20
7.2 General grid . 20
7.3 Regular grid axis . 25
7.3.1 Overview . 25
7.3.2 Index Axis .27
7.3.3 Regular Axis .27
7.4 Irregular grid axis . 28
7.4.1 Overview . 28
7.4.2 Irregular independent grid axes . 29
7.4.3 Irregular correlated grid axes .31
7.5 Transformation grid .32
7.5.1 Transformation .32
7.5.2 SensorML . 33
7.6 Number of direct positions in grid . 35
8 Multi-Curve Coverage .35
9 Multi-Surface Coverage .36
10 Multi-Solid Coverage .37
11 Coverage partitioning.38
11.1 Overview . 38
11.2 Partitioning . 38
11.3 CRS and partition envelope constraints . 40
11.4 Domain set constraints .41

iii
ISO/DIS 19123-2:2025(en)
11.5 Range type constraints .42
12 Coverage encodings .42
12.1 Overview .42
12.2 XML .42
12.2.1 Relation with GML . .43
12.3 JSON Coverage .43
12.4 Multipart encoding . 44
12.4.1 Overview . 44
12.4.2 Root part . 44
12.4.3 Further parts .45
Annex A (normative) Abstract test suite .46
Annex B (normative) Rectified and Referenceable Grid Coverages .48
Bibliography .55

iv
ISO/DIS 19123-2:2025(en)
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.
The procedures used to develop this document and those intended for its further maintenance are described
in the ISO/IEC Directives, Part 1. In particular the different approval criteria needed for the different types
of ISO documents should be noted. This document was drafted in accordance with the editorial rules of the
ISO/IEC Directives, Part 2 (see www.iso.org/directives).
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. Details of any patent
rights identified during the development of the document will be in the Introduction and/or on the ISO list of
patent declarations received (see iso.org/patents).
Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.
For an explanation on the voluntary nature of standards, the meaning of ISO specific terms and
expressions related to conformity assessment, as well as information about ISO's adherence to the World
Trade Organization (WTO) principles in the Technical Barriers to Trade (TBT) see the following URL:
iso.org/iso/foreword.html.
This document was prepared by Technical Committee ISO/TC 211, Geographic information/Geomatics, in
collaboration with the European Committee for Standardization (CEN) Technical Committee CEN/TC 287,
Geographic Information, in accordance with the Agreement on technical cooperation between ISO and
CEN (Vienna Agreement), under participation of the IEEE GRSS Earth Science Informatics (ESI) Technical
Committee, and derived from the Open Geospatial Consortium (OGC) standards CIS 1.0 and CIS 1.1 with
permission.
A list of all the parts in the ISO 19123 series can be found on the ISO website.
Any feedback or questions on this document should be directed to the user’s national standards body. A
complete listing of these bodies can be found at iso.org/members.html.

v
ISO/DIS 19123-2:2025(en)
Introduction
This 19123-2 Coverage Implementation Schema (CIS) specifies an interoperable, conformance-testable
[10]
information schema for coverages. As defined in ISO 19123-1:2023 (which is equivalent to OGC Abstract
Topic 6.1), coverages serve as digital representations of space-time varying phenomena, corresponding to
the notion of a “field” in physics. Such coverages can be discrete or continuous. Common examples include
1-D time series, 2-D imagery, 3-D x/y/t image time series and x/y/z geophysical voxel models, as well as 4-D
x/y/z/t atmospheric and ocean data. Coverages are independent from service definitions and, therefore, can
be accessed through a variety of web based service types, such as the OGC Web Coverage Service (WCS)
[6]
Standard, and through service instantiations realizing ISO 19123-3.
CIS is a compliant standardization target of ISO 19123-1:2023 relying on its concepts, terms, definitions, and
interfaces to establish a logical schema (via UML) implementing the interfaces defined there. Additionally,
this document defines related physical coverage schemas (via format encodings) for the single logical
schema. Thus, both standards together establish an abstraction hierarchy:
— conceptual level: ISO 19123-1 defining abstract interfaces;
— logical level: Clauses 5 – 0 of this document, defining data as object classes with attributes;
— physical level: Clause 12 of this document, plus further separate coverage encoding standards, defining
the mapping of the logical-level data to byte streams (such as GeoTIFF, NetCDF, JPEG2000, etc.).
The main changes of this document over its predecessor version ISO 19123-2:2018 are as follows:
— The document is adjusted to the structure established in ISO 19123-1. Among others, a clear separation
of logical level (UML structures) and physical level (encodings, such as XML) is established.
— Use of terminology is adjusted to ISO 19123-1.
[18]
— Coverage type GeneralGridCoverage is integrated from OGC CIS 1.1 as an additional coverage structure
which generalizes and simplifies grid coverage modelling. It adds comprehensive definitions for all
possible types of irregular grids, including RectifiedGridCoverage and ReferenceableGridCoverage as
special cases.
— RectifiedGridCoverage and ReferenceableGridCoverage have been moved into a (normative) annex as
their specification follows a different logic which does not easily fit into the structuring given by the
Coverage Fundamentals (ISO 19123-1). They form a legacy and will be deprecated in the next version as
GeneralGridCoverage covers these cases while simpler in structure.
— Structure and nomenclature are adjusted to new ISO requirements.
— The UML schema is updated to reflect the above adjustments.
— Complement the XML coverage encoding with equivalent JSON encodings.
Note The RDF encoding of OGC CIS 1.1 has not been included at this time and is left for future work.
Technically, this document implements the following improvements over the previous version:
— More general grid identifiers (with punctuation, national character sets, etc.).
— Mixed regular and non-regular grids.
— Added support for non-regularly gridded sensor models.
— Clear regulation for interpolation methods associated with grid coverages, thereby also clarifying a
long-standing confusion between discrete and continuous grid coverages.
— Distinction between grid dimension and CRS dimension.
— Introduction of EnvelopeByAxis, an envelope type which allows for a convenient handling of any type of
coordinates.
vi
ISO/DIS 19123-2:2025(en)
— Partitioned (“tiled”) coverages, allowing – among others – “interleaved representations” of coverages
and datacubes tiled for efficient subsetting.
— Removal of a namespace ambiguity in ReferenceableGridCoverage (resolved by introduction of
GeneralGridCoverage).
— Some GML schema definitions whose generality complicates coverage understanding unnecessarily have
been extracted and condensed into the pertaining XML schema. This remedies an often heard complaint
about the complexity not of the coverage model, but the underlying GML. As a consequence, the XML
encoding of this document is not a GML application schema any longer, but a compact, freestanding
definition. Nevertheless, by keeping with the coverage types inherited from 19123-2:2018 it is possible
for implementers to remain in the realm of a GML application schema.

vii
DRAFT International Standard ISO/DIS 19123-2:2025(en)
Geographic information — Schema for coverage geometry
and functions —
Part 2:
Coverage implementation schema
1 Scope
1)
This document specifies a concrete , implementable, conformance-testable coverage structure based on the
abstract schema for coverages defined in the ISO 19123-1 coverage fundamentals. This document defines a
concrete data structure that is suitable for encoding in many formats.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content constitutes
requirements 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 19123-1:2023, Geographic information — Schema for coverage geometry and functions — Part 1:
Fundamentals
ISO 19136-1:2020, Geographic information — Geography Markup Language (GML) — Part 1: Fundamentals
OGC 08-094r1, OGC® SWE Common Data Model Encoding Standard, version 2.0
3 Terms, definitions, and abbreviated terms
3.1 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
— IEC Electropedia: available at https:// www .electropedia .org/
— ISO Online browsing platform: available at https:// www .iso .org/ obp
3.1.1
coverage CRS
CRS (as per 19111:2019) in which domain set coordinates of a given coverage are expressed
3.1.2
displaced grid
grid whose direct positions are topologically aligned to a grid, but whose geometric positions
can vary arbitrarily
3.1.3
irregular grid
grid whose direct positions have individual distances along each grid’s axis
1) “concrete“ is used here as a contrast to “abstract” in the sense described in the Introduction.

ISO/DIS 19123-2:2025(en)
3.1.4
partition
separately stored coverage acting, by being referenced in another coverage, as one of its
components
3.1.5
regular grid
grid whose direct positions have a constant distance along each grid’s axis
3.1.6
transformation grid
grid whose direct positions are given by a transformation algorithm not further specified in this
document
Note 1 to entry: This definition is adapted from OGC 08-094r1.
3.2 Abbreviated terms
CIS Coverage Implementation Schema
CRS Coordinate Reference System
EPSG European Petroleum Survey Group
GeoTIFF Geo Tagged Image File Format
GML Geography Markup Language
JSON JavaScript Object Notation
netCDF network Common Data Format
OGC Open Geospatial Consortium
RDF Resource Description Framework
SWE Sensor Web Enablement
TIN Triangulated Irregular Network
UoM Unit of Measure
UML Unified Modeling Language
WCS Web Coverage Service
WCPS Web Coverage Processing Service
4 Conformance
4.1 Notation
Schemas are presented using the Unified Modeling Language (UML) as defined in the ISO 19103:2024
[40]
Conceptual Schema Language .
4.2 Interoperability and conformance testing
[10]
The term “coverage”, together with related terms, is used as defined in ISO 19123-1:2023. This Coverage
Implementation Schema standard realizes Clauses 5 through 10 of ISO 19123-1:2023 (Annex D is realized by

ISO/DIS 19123-2:2025(en)
normative Annex B of this document). In other words, the data structures defined in the UML schema form
an implementation of the interfaces established in ISO 19123-1:2023.
This document defines testable conformance classes which correspond to the requirements in Clause 5
onwards. These conformance classes, together with the corresponding conformance tests, are described
in Annex A. Any implementation claiming conformance with this document must conform to the abstract
conformance class coverage and, in addition, at least one of the conformance classes xml, json, multipart.
4.3 Organization
The coverage schema is organized into the packages shown in Figure 1. Each package establishes one
requirements class. Figure 1 show the requirements class dependencies depicted as a UML package
diagram; each package represents one class, the depends-on relationship represents the requirements class
dependency relationship. Packages have been grouped along practical implementation considerations, in
particular to maximize modularity (Figure 1):
— The core class coverage (in red). This is the only abstract class – it establishes the basic framework, while
the concrete conformance classes listed below define how concrete coverage instances can be built.
— The grid coverage classes (in green):
— Class grid-regular establishes multi-dimensional unreferenced and regular referenced grids; in
particular, GridCoverage and RectifiedGridCoverage are provided here for backwards compatibility
with version 1.0 of this standard.
— Class grid-irregular establishes multi-dimensional irregular referenced grids.
— Class grid-transformation establishes multi-dimensional referenced grids defined by algorithmic
transformations.
— The non-gridded coverage classes (in blue):
— Class pointcloud establishes point clouds, a class kept separately as it frequently appears standalone
in practice.
— Class mesh establishes general multi-dimensional geometric meshes with curves, surfaces, and solids.
— The format encoding classes (in yellow):
— Class xml-coverage establishes XML encoding of coverages.
— Class json-coverage establishes JSON encoding of coverages.
— Class multipart establishes a multipart encoding of coverages.
— Class partitioning (in grey) establishes coverages composed from several sub-coverages.

ISO/DIS 19123-2:2025(en)
Figure 1 — The Coverage class hierarchy as UML package diagram
Requirement 1:  https:// standards .isotc211 .org/ 19123/ -/ 2/ req/ coverage/ conformance
An implementation of this CIS standard, in order to be compliant, shall comply with:
—  the core conformance class coverage plus
—  at least one of the grid-regular, grid-irregular, grid-transformation, pointcloud, and mesh conformance
classes plus
—  at least one of the encoding conformance classes xml-coverage and json-coverage.
All requirements-classes and conformance-classes described in this document are owned by the standard(s)
identified.
The URIs in this standard have a stem of https:// standards .isotc211 .org/ 19123/ -2/ 2/ which corresponds
to the OGC URI stem https:// www .opengis .net/ spec/ CIS/ 1 .1/ , except that the numbering (such as of
requirements) has changed sometimes.
Table 1 — Package URIs established in this standard
Class Description and URI
coverage General, abstract coverage class, implementing ISO 19123-1:2023
https:// standards .isotc211 .org/ 19123/ -2/ 2/ coverage
pointcloud Coverage specialization for Multi-Point Coverages (point clouds)
https:// standards .isotc211 .org/ 19123/ -2/ 2/ pointcloud
grid-regular Coverage specialization for regular Grid Coverages
https:// standards .isotc211 .org/ 19123/ -2/ 2/ grid -regular
grid-irregular Coverage specialization for irregular Grid Coverages
https:// standards .isotc211 .org/ 19123/ -2/ 2/ grid -irregular
grid-transformation Coverage specialization for transformation Grid Coverages
https:// standards .isotc211 .org/ 19123/ -2/ 2/ grid -transformation
mesh Coverage specialization for curve, surface, and solid coverages
https:// standards .isotc211 .org/ 19123/ -2/ 2/ mesh
partitioning Partitioned representation of coverages
https:// standards .isotc211 .org/ 19123/ -2/ 2/ partitioning

ISO/DIS 19123-2:2025(en)
TTaabbllee 11 ((ccoonnttiinnueuedd))
Class Description and URI
xml-coverage Coverage encoding in XML
https:// standards .isotc211 .org/ 19123/ -2/ 2/ xml -coverage
json-coverage Coverage encoding in JSON
https:// standards .isotc211 .org/ 19123/ -2/ 2/ json -coverage
multipart Multi-part representation of coverages
https:// standards .isotc211 .org/ 19123/ -2/ 2/ multipart
This Coverage Implementation Schema consists of the UML diagrams and textual requirements classes
established in this document as well as an external file bundle consisting of the corresponding schema files,
plus example coverage files. The URL root
The name and contact information of the maintenance agency for this document can be found at www .iso
.org/ maintenance _agencies.
5 Coverages
5.1 Overview
Conformance class coverage lays the foundation for the Coverage Implementation Schema. It is the abstract
core class, meaning it does not allow creating coverage instances itself, but rather provides the fundament
for the further classes which define various specializations of coverage instances.
[10]
Following ISO 19123-1:2023 coverages are sorted along the topological dimension of the elements they
contain (Figure 2), visible in their respective domain set structure:
— 0D point sets, known as Multi-Point Coverages for irregular point agglomerations (see Subclause 6) and
General Grid Coverages for points sitting on some regular or irregular grid (see Subclause 7);
— 1D curve bundles, known as Multi-Curve Coverages (see Subclause 8);
— 2D surface bundles, known as Multi-Surface Coverages (see Subclause 9);
— 3D solid bundles, known as Multi-Solid Coverages (see Subclause 0).
Figure 2 — Coverage subtypes defined in CIS (overview)
Requirement 2:  https:// standards .isotc211 .org/ 19123/ -/ 2/ req/ coverage/ subtypes
A coverage shall be one of: MultiPointCoverage, GeneralGridCoverage, MultiCurveCoverage,
MultiSurfaceCoverage, MultiSolidCoverage.
NOTE This structuring, adopted from ISO 19123-1:2023, is different from the previous edition of this standard.

ISO/DIS 19123-2:2025(en)
5.2 Terminology
The following terms used are imported from other standards, mainly ISO 19123-1:2023, and used in addition
to those defined in Clause 3.
3.1.1
axis
tuple of axis name, axis abbreviation, axis direction, axis unit, and further
information as specified in ISO 19123-1
[SOURCE: ISO 19123-1:2023, 3.1.2]
[SOURCE: ISO 19123-1:2023, 3.1.2]
3.1.2
coordinate
one of a sequence of measures designating the position of a point
Note 1 to entry In a coordinate reference system, the coordinate numbers are usually qualified by units. Some
coordinates may use a unit representation, for example date/time conformant with ISO 8601-1. When coordinates are
an index (ordinal coordinates) they are unitless (which possibly can be represented by a unit of 1).
[SOURCE: ISO 19123-1:2023, 3.1.5]
3.1.3
coordinate reference system
coordinate system that is related to an object by a datum
[SOURCE: ISO 19123-1:2023, 3.1.6]
3.1.4
coordinate tuple
tuple composed of coordinates
Note 1 to entry The number of s in the coordinate tuple equals the dimension of the coordinate system; the order of
coordinates in the coordinate tuple is identical to the order of the axes of the coordinate system.
[SOURCE: ISO 19123-1:2023, 3.1.8]
3.1.5
coverage
function which returns values from its range type for any direct position within its domain
[SOURCE: ISO 19123-1:2023, 3.1.9]
3.1.6
direct position
position inside one of the geometric objects in a coverage described by a coordinate tuple within
the coverage coordinate reference system
Note 1 to entry A direct position is described by an ordered sequence of coordinates. The number of elements in a
direct position is established by the number of axes of the coverage CRS.
[SOURCE: ISO 19123-1:2023, 3.1.14 – Note 2 removed]

ISO/DIS 19123-2:2025(en)
3.1.7
domain
set of geometric objects
Note 1 to entry Examples of such geometric objects are points, lines, faces, and solids. All elements within a domain
(set) are of a single given type.
[SOURCE: ISO 19123-1:2023, 3.1.16]
3.1.8
geometric dimension
largest number n such that each point in a set of points can be associated with a subset
n
that has that point in its interior and is topologically isomorphic to 𝔼 , Euclidean n-space
[SOURCE: ISO 19123-1:2023, 3.1.22]
3.1.9
georectified
corrected for positional displacement with respect to the surface of the Earth
Note 1 to entry This term is kept only for backwards compatibility and is not fundamental to the coverage definition
of this document.
[SOURCE: ISO 19123-1:2023, 3.1.25 adopted from ISO 19115-2:2019, 3.11]
3.1.10
georeferenceable
associated with a geopositioning information that can be used to convert grid coordinate values to values of
coordinates referenced to an external coordinate reference system related to the Earth by a datum
Note 1 to entry This term is kept only for backwards compatibility and is not fundamental to the coverage definition
of this document.
[SOURCE: ISO 19123-1:2023, 3.1.26]
3.1.11
grid
covering of a multi-dimensional region using quadrilateral shapes (in the 2D case) or their
n-dimensional generation (in the n-D case) with no overlaps and gaps
Note 1 to entry The term grid originates historically from a 2D view: In 19123:2005 a grid consists of a network
composed of one or more sets of curves in which the members of each set intersect the members of the other sets.
Meantime, nD grids (including 1D) are known and in use. The “covering” of a region is also known as a tessellation in
mathematics.
Note 2 to entry The 19123:2005 definition is equivalent to the revised definition of this document.
[SOURCE: ISO 19123-1:2023, 3.1.28]
3.1.12
index coordinate reference system
index CRS
coverage CRS in which all axes are Cartesian

ISO/DIS 19123-2:2025(en)
[SOURCE: ISO 19123-1:2023, 3.1.35]
3.1.13
mesh
coverage consisting of a collection of curves, surfaces, or solids, respectively
[SOURCE: ISO 19123-1:2023, 3.1.36]
3.1.14
point coverage
coverage that has a domain composed of points
[SOURCE: ISO 19123-1:2023, 3.1.39]
3.1.15
range (set)
set of values associated by a function, the coverage, with the domain of a coverage
Note 1 to entry This is consistent with the more generic definition of range in ISO 19107:2019.
Note 2 to entry Coverage range types and values correspond to the notion of feature attribute types and values.
[SOURCE: ISO 19123-1:2023, 3.1.41]
3.1.16
rectified grid
grid for which there is an affine transformation between the grid coordinates and the coordinates of an
external coordinate reference system
Note 1 to entry If the coordinate reference system is related to the Earth by a datum, the grid is a georectified grid.
Note 2 to entry This term is kept only for backwards compatibility and is not used in nor fundamental to the coverage
definition of this document.
[SOURCE: ISO 19123-1:2023, 3.1.43]
3.1.17
referenceable grid
grid with an external coordinate reference system whose type is either geodetic or projected
Note 1 to entry If the coordinate reference system is related to the Earth by a datum, the grid is a georeferenceable grid.
Note 2 to entry This term is kept only for backwards compatibility and is not used in nor fundamental to the coverage
definition of this document.
[SOURCE: ISO 19123-1:2023, 3.1.44]
3.1.18
sensor model
description of the radiometric and geometric characteristics of a sensor
[SOURCE: ISO 19101-2:2018, 3.37]
3.1.19
ISO/DIS 19123-2:2025(en)
solid
geometric set with three spatial dimensions
Note 1 to entry This is consistent with the definition in ISO 19107:2019
Note 2 to entry A solid may have further dimensions, such as time.
[SOURCE: ISO 19123-1:2023, 3.1.45]
3.1.20
transformation grid
grid whose direct positions are given by a transformation algorithm not further specified in this
document
Note 1 to entry This definition is adapted from OGC 08-094r1.
5.3 General coverage structure
A coverage consists of the following main components (Figure 3):
— Domain set: “where are values available?” Coordinate positions for which values are stored in the
coverage are called direct positions.
— Range set: “what is the value at a particular position?” (often referred to as “pixels” or “voxels”). Such
values can be atomic (such as in grayscale images) or record structures (such as in color or hyperspectral
images). Record components are known as bands, channels, and variables in different disciplines.
— Range type: “what do these values mean?” Such a type often consists of one or more fields (also referred
to as bands or channels or variables – not to be confused with the physics field a coverage represents).
[16]
For this description of the semantics, coverages in this document make use of OGC SWE Common .
— Metadata: “what else do we know about this coverage?” This item is added in this document over
ISO 19123-1:2023.
Technically, all coverage types are derived from abstract class Coverage. This structure contains a DomainSet
describing the coverage’s domain and a RangeSet component containing the range value consisting of one
or more record fields. The RangeType element describes the coverage's range data structure. Its structure
description is based on the OGC SWE Common [OGC 08-094r1] DataRecord, so that the semantics description
from upstream sensor acquisitions into downstream services is carried over seamlessly.
In conformance class coverage, this domain/range representation is used; requirements class coverage-
partitioning (Clause 0) adds partitioning and position/value pair list as alternatives. This is why coverage
subtype CoverageByDomainAndRange is introduced in Figure 3; while it may seem artificial in this
requirements class, it will allow modelling the alternative representations later in this document.
Figure 3 contains the complete coverage structure with all variants allowed; in the subsequent subclauses,
all parts are successively described in detail.
[39]
NOTE OGC Web Coverage Processing Service (WCPS) defines a coverage-specific query language based on this
coverage standard allowing extraction, recoding, fusion, derivation of coverages and general analytics, currently on
multi-dimensional grid coverages aka geo datacubes.

ISO/DIS 19123-2:2025(en)
Figure 3 — The Coverage structure (overview)
5.4 Domain/range based coverage structure
The coverage structure defined normatively in this class coverage is CoverageByDomainAndRange.
Requirement 3:  https:// sta
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