Introduction
The EO Glossary of Terms and Definitions serves as a reference for everyone involved in Earth Observation. It covers a wide range of terms, concepts, and definitions relevant to EO disciplines including remote sensing, satellite imagery, geospatial analysis, calibration and validation, climate adaptation, and more.
This glossary strives to consolidate definitions where appropriate, while acknowledging the necessity of definitional plurality where communities legitimately differ. Unlike many online glossaries, it is interactive and participative — a living document in constant evolution, with full version traceability at the individual term level.
Principles
This glossary implements the recommendations of:
- Strobl, Woolliams & Molch (2024) — Lost in Translation: The Need for Common Vocabularies and an Interoperable Thesaurus in Earth Observation Sciences, Surveys in Geophysics. doi:10.1007/s10712-024-09854-8
- CEOS Interoperability Handbook 2.0 — Semantic Recommendations SEM#1 through SEM#6 and Thesaurus Recommendations THES#1 through THES#8.
Key principles (THES#1–8):
- Terms are classified as base, core, controversial, or high-impact (see Concepts)
- Definitions are written in substitutable form — they can replace the term in a sentence
- Explanatory notes and examples are kept in separate sections from the core definition
- Every definition links to its source
- Controversial terms include multiple definitions with explicit disambiguation
- All changes are version-controlled at the individual term level via Git
Resources & Reference Glossaries
| Vocabulary | Organisation | Scope |
|---|---|---|
| IPCC Glossary | IPCC | Climate science |
| UNTERM | United Nations | Multilingual UN terminology |
| ISO Geolexica | ISO/TC 211 | Geographic information |
| OGC Rainbow | OGC | Geospatial standards |
| BIPM VIM | JCGM | Metrology |
| JCGM GUM | JCGM | Measurement uncertainty |
| CEOS-ARD | CEOS | Analysis Ready Data |
| CEOS Cal/Val Wiki | CEOS WGCV | Calibration & Validation |
| FIDUCEO | Reading/NPL | Metrological EO terms |
| WMO-WIGOS | WMO | Observing systems |
| INSPIRE Glossary | EU INSPIRE | European spatial data |
| NASA GCMD Keywords | NASA | Earth science keywords |
| GCOS-154 | WMO/GCOS | Climate observation |
| EFSG | EFGS | Geospatial statistics |
| ISO 8601-1:2019 | ISO | Date and time |
| ISO 19179-1:2021 | ISO/TC 211 | Discrete Global Grid Systems |