ISO 19111:2019/Amd 2:2023 – Geographic Information Referencing by Coordinates Amendment 2
Overview
ISO 19111:2019/Amd 2:2023 is an important amendment to the International Standard focusing on geographic information and the referencing of spatial data by coordinates. This update enhances the definitions and classifications within coordinate reference systems (CRS), datums, and coordinate operations, supporting improved precision and interoperability in geospatial data management. Developed by ISO Technical Committee ISO/TC 211 in cooperation with CEN and OGC, this amendment refines key terminologies and UML model representations to maintain relevance with evolving geospatial technologies.
Key Topics
1. Datum Ensemble
- Defined as a group of multiple realizations of the same terrestrial or vertical reference system used for approximate spatial referencing.
- Enables seamless merging of datasets referenced to different realizations within the ensemble without requiring coordinate transformations.
- Approximate spatial differences are typically under 1 decimetre, tolerating up to 2 meters depending on user context.
2. Geodetic Coordinate Reference System (CRS)
- Specifies two- or three-dimensional coordinate systems based on a geodetic reference frame.
- Can include Cartesian, ellipsoidal (geographic), or spherical coordinate systems.
- Highlights the dynamic or static nature of geodetic CRSs depending on the reference frame stability.
3. Spherical Coordinate System
- A two- or three-dimensional Euclidean coordinate system defined by two angular coordinates and, if 3D, one distance coordinate measured from the origin.
- Clarifies distinctions between spherical and ellipsoidal coordinate systems to avoid confusion.
4. Expanded Coordinate Reference System Types
- Addition of derived projected 2D + vertical CRS and derived projected 2D + engineering 1D (near vertical) CRS to support complex spatial referencing needs.
- Introduction of spatio-parametric CRS combining geographic or projected 2D CRS with one or more parametric CRS for enhanced dimensional modeling.
5. UML Modelling and Documentation Enhancements
- Updated UML diagrams reflect refined associations among coordinate systems, datums, and coordinate operations.
- Comprehensive tables define class attributes and constraints for Geodetic CRS, Vertical CRS, Coordinate Systems (including SphericalCS), and Datum classes ensuring clarity in implementation.
Applications
ISO 19111:2019/Amd 2:2023 is essential for professionals working with geographic information systems (GIS), geodesy, cartography, and spatial data infrastructure development. It supports:
- Accurate geospatial data referencing and integration from diverse sources.
- Harmonized use of coordinate reference systems across international mapping and surveying projects.
- Dynamic modeling of earth coordinates accounting for tectonic, crustal motion, and vertical height changes.
- Enhanced 3D and 4D spatial analysis through spatio-parametric coordinate reference systems.
- Improved data interoperability for applications such as satellite navigation, land surveying, environmental monitoring, and urban planning.
Related Standards
- ISO 19111:2019 – Original third edition of the Geographic Information – Referencing by Coordinates standard.
- ISO/IEC Directives Part 1 & 2 – Guidelines for drafting and maintaining ISO standards documents.
- ISO/TC 211 Standards – A suite of standards covering geographic information and geomatics.
- OGC Specifications – Collaborating specifications on geospatial data formats and coordinate referencing.
- European Committee for Standardization (CEN) EN ISO 19111 – Harmonized European adoption of this international standard.
Summary
The amendment ISO 19111:2019/Amd 2:2023 is a significant update in geographic coordinate referencing standards, introducing enhanced definitions, system extensions, and UML model improvements. These refinements improve precision, support complex coordinate referencing scenarios, and foster interoperability critical for modern geospatial data applications globally. Adopting this amendment ensures alignment with international best practices in geographic information management.
