Nexus Standards · NS-3b · Proposed
NS-3b
NS-3b: Dataset and product metadata profile (STAC, DCAT, PROV-O)
NS-3b is a proposed Nexus Standard; the artifacts it governs are identified by UNIs (Unique Nexus Identifier). NS-3b specifies how a dataset or product identified by a UNI is described for the geospatial, open-data and provenance communities, so that one catalog record feeds a STAC catalog, a DCAT catalog and a PROV-O graph without being described again. The UNI stays the key; every external identifier is a crosswalk from it.
Read a UNI.
Type or paste a Uniform Nexus Identifier: each segment is decoded against grammar 0.2 and the region, when it names a country, is lit on the globe above.
Summary
- Statusproposed
- Responsible scopetrust, authorization and assurance; canonical risk data, records and provenance
- Identifier
NXS-STD-SW-000005 - Rules stated0
- Programme areas14
- Source filesrepository
Nexus Standards · proposed
Status of NS-3b
Preparatory working draft, circulated for review and comment. Not for implementation. Prepared and circulated by The Secretariat of the Nexus Standards, Global Centre for Risk and Innovation (GCRI Canada) (public@therisk.global), 17 October 2026. Technical review area: TR-02. This document is not a Nexus Standard; it may change without notice and is not to be implemented, relied upon or cited as a Nexus Standard. Its stage is designated only by the Global Standards Council and its technical committees under NS-13. Recipients are invited to submit comments with supporting reasons, and to notify any patent rights of which they are aware. See the notice of circulation.
The land surface from orbit in the Amazon Basin
The map frames the Amazon Basin as an example geography for dataset footprints and Earth observation metadata; the frame gives context and is not a statement of where the standards apply. Shown at first: true colour (VIIRS NOAA-20 corrected reflectance, NASA LANCE). The layer drawer adds land cover type (IGBP), yearly (MODIS Terra and Aqua land cover, MCD12Q1); enhanced vegetation index, rolling 8 days (MODIS Terra EVI); snow cover (VIIRS NOAA-20 NDSI); and sea ice concentration (GHRSST MUR). NASA products are served through NASA GIBS under NASA's open data policy, with acknowledgement; coastlines, boundaries and place names come from NASA GIBS reference layers (© OpenStreetMap contributors, ODbL) and Natural Earth (public domain). Each layer shows its own observation date; full credits are given under the map.
The interactive map needs JavaScript; the layer list and sources are below.
Layers 1
Earth observation
Keyboard, with the map focused
Hold Ctrl or ⌘ and scroll to zoom
Latest available
NASA GIBS / EOSDIS · ASTER GDEM (METI, NASA) · Blue Marble (NASA) · © OpenStreetMap contributors (ODbL) · Natural Earth
Loading the latest NASA imagery.
Drag to move. Ctrl or ⌘ and scroll, pinch or the buttons to zoom; hover for the values under the pointer; reset returns to the region.
True-colour imagery, land cover, vegetation, snow and sea ice, framed on the Amazon Basin.Satellite and model products as NASA publishes them, each with its own date; indicators, not assessments of any place.
Data: NASA GIBS · ASTER GDEM · Blue Marble · © OpenStreetMap contributors · Natural Earth · NASA EONETSources and licences
- We acknowledge the use of imagery provided by services from NASA's Global Imagery Browse Services (GIBS), part of NASA's Earth Science Data and Information System (ESDIS). Colours redrawn from the published colour map; values averaged into H3 cells where shown (modified). NASA open data
- We acknowledge the use of imagery provided by services from NASA's Global Imagery Browse Services (GIBS), part of NASA's Earth Science Data and Information System (ESDIS). Colours redrawn from the published colour map; values averaged into H3 cells where shown (modified). NASA open data
- VIIRS near-real-time products (flood, land surface temperature, snow cover, corrected reflectance), NASA LANCE; imagery via NASA GIBS. Colours redrawn from the published colour map; values averaged into H3 cells where shown (modified). NASA open data
- MODIS land products (vegetation indices, gross primary production, land cover), NASA LP DAAC and LANCE; imagery via NASA GIBS. Colours redrawn from the published colour map; values averaged into H3 cells where shown (modified). NASA open data
- GHRSST Level 4 MUR analyses, NASA Jet Propulsion Laboratory; distributed by the NASA Physical Oceanography DAAC (PO.DAAC); imagery via NASA GIBS. Colours redrawn from the published colour map; values averaged into H3 cells where shown (modified). NASA open data
- ASTER GDEM is a product of METI and NASA (ASTER Global Digital Elevation Model V003, NASA LP DAAC); imagery via NASA GIBS. Colours redrawn from the published colour map; values averaged into H3 cells where shown (modified). Cite as: NASA/METI/AIST/Japan Spacesystems and U.S./Japan ASTER Science Team (2019). ASTER Global Digital Elevation Model V003. doi:10.5067/ASTER/ASTGTM.003. NASA open data
- Made with Natural Earth. Free vector and raster map data @ naturalearthdata.com. Public domain
- © OpenStreetMap contributors (ODbL), via NASA GIBS (coastlines, boundaries, roads and place names). Colours redrawn from the published colour map; values averaged into H3 cells where shown (modified). ODbL
- Blue Marble, NASA Earth Observatory; imagery via NASA GIBS. Colours redrawn from the published colour map; values averaged into H3 cells where shown (modified). NASA open data
- Context on the globe and flat map: coastlines, boundaries, roads and place names from NASA GIBS reference layers (OpenStreetMap data, ODbL, © OpenStreetMap contributors); Blue Marble imagery as an optional base; 3D terrain and the elevation read-out from the ASTER GDEM elevation colour index (5 m to 200 m classes, exaggerated for legibility). Boundaries are drawn as published and imply no position on any territory.
- Globe: MapLibre GL JS 6.9.1, BSD-3-Clause, © MapLibre contributors.
- Live: NASA EONET Events are indicative, not authority warnings.
- NASA GIBS: We acknowledge the use of imagery provided by services from NASA's Global Imagery Browse Services (GIBS), part of NASA's Earth Science Data and Information System (ESDIS).
- Past year, daily temperature and sunshine (NASA POWER): These data were obtained from the NASA Langley Research Center (LaRC) POWER Project funded through the NASA Earth Science/Applied Science Program..
- Optional layers (9 sources in the layer list: live, forecast, observed and context) print their provider credit on the map and here when switched on; forecasts are model output and derived indices are estimates.
Layers and dates
- True colour: VIIRS NOAA-20 corrected reflectance, NASA LANCE · 13 Oct 2026
- Land cover type (IGBP), yearly: MODIS Terra and Aqua land cover (MCD12Q1), NASA LP DAAC · 2024
- Enhanced vegetation index, rolling 8 days: MODIS Terra EVI, NASA LANCE · 13 Oct 2026
- Snow cover: VIIRS NOAA-20 NDSI, NASA LANCE · 13 Oct 2026
- Sea ice concentration: GHRSST MUR, NASA JPL PO.DAAC · 12 Oct 2026
NS-3b among the standards.
Fig.The standards on which NS-3b builds, those that cite it and the programme areas where it applies, from the texts and the registry.
The standard as a process
A UNI (Unique Nexus Identifier)-keyed record is described once and exported as a STAC Item, a DCAT 3 dataset and a PROV-O bundle; record references become provenance entities a correction replay can walk; status fields and licences are carried verbatim. 7 operations in 5 phases; each states its actor, its decision rule, the record it leaves and the rule identifiers it implements (3 rules of NS-3b and the standards it applies).
All operations in order (7)
- 01
UNI-keyed record start · Record
The dataset or product is described once, in its catalog record.
- Who
- the publisher of record
- Decision rule
- the UNI stays the key; every external identifier is a crosswalk from it
- Record
- the catalog record of a dataset or product
- Implements
- NS1-R4
- 02
STAC Item step · Profiles
Each location becomes an asset with its checksum where a digest is recorded; a cite-as link points to the DOI where one exists.
- Who
- the export service
- Decision rule
- STAC 1.0 profile (section 1)
- Record
- an Item whose id is the UNI, with nexus properties and one asset per location
- 03
DCAT 3 dataset step · Profiles
Identifier, licence, publisher, creators with ORCID IRIs and the resolver landing page are mapped from the record.
- Who
- the export service
- Decision rule
- DCAT 3 profile (section 2)
- Record
- a dcat:Dataset in JSON-LD with one distribution per location
- 04
PROV-O bundle step · Profiles
Derived-from, revision, invalidation and membership relations become PROV-O predicates.
- Who
- the export service
- Decision rule
- DataCite relations map to PROV predicates (section 3)
- Record
- a prov:Bundle with one entity per UNI
- 05
Record dependencies record · Provenance
Record references keep their version, so a correction to one record can be traced to every product that used it.
- Who
- the export service
- Decision rule
- versions are revisions of their predecessors so that a correction replay can walk the graph
- Record
- record references as prov:used entities, each a specialisation of its record concept
- Implements
- NS2-R4
- 06
Carry states as is gate · Checks
Legal state, claim level and status pass through unchanged; a restrictive licence stays restrictive in every format.
- Who
- the export service
- Decision rule
- the profile describes and asserts nothing; a proprietary licence is never mapped to an open licence (section 4)
- Record
- status fields and licence carried verbatim
- Implements
- NS0-P8
- 07
Export by format end · Export
Catalogues, open-data portals and provenance graphs read the same record without a second description.
- Who
- any client
- Decision rule
- every catalogued artifact can be exported in each format
- Record
- format=stac, dcat or prov from the record's export path
Fig.Phases read left to right; each card names the operation, its actor and the record it leaves, and each edge label names the hand-over. Play, step or scrub; the detail panel gives the full text of the selected operation. Sources: NS-3b: Dataset and product metadata profile · NS-1: The UNI and the artifact catalog · NS-2: Citation and attribution format for UNIs · NS-0: Constitution and principles.
NS-3b clause by clause
5 clauses and 0 rules as stated in the standard, presented with numbered clauses, stable rule anchors, versions and changes.
STAC
A record is exported as a SpatioTemporal Asset Catalog (STAC) Item conforming to STAC 1.1 (an Item that conforms to 1.0 remains readable). The Item's id is the UNI. It carries the properties nexus:uni, nexus:urn, nexus:scope, nexus:category, nexus:region, nexus:legalState, nexus:claimCeiling and nexus:status; one asset per location (with file:checksum when a digest is recorded); a cite-as link to the DOI when one exists; and related links to other UNIs. Geometry, bounding box and datetimes are only what the caller states; nothing is inferred from the REGION segment, because a country code is not a footprint. Without a stated extent, the Item has geometry: null and datetime: null, which STAC permits and which is the honest state. A set of records is exported as a STAC Collection of Items.
DCAT 3
A record is exported as a dcat:Dataset in JSON-LD under the W3C Data Catalog Vocabulary (DCAT) Version 3: dct:identifier carries the URN and the DOI; dct:license the SPDX licence IRI (or the LicenseRef- string unchanged); dct:publisher the publisher of record; dct:creator the persons and organisations, with ORCID iDs and ROR IDs as IRIs; one dcat:Distribution per location; dcat:landingPage the resolver page; and dct:relation the related identifiers. The honesty fields (nexus:legalState, nexus:claimCeiling, nexus:status) travel with the dataset.
PROV-O
A record is exported as a prov:Bundle (W3C PROV-O) with one prov:Entity per UNI. DataCite relation types map to PROV predicates:
| relatedIdentifiers.relation | PROV-O |
|---|---|
| IsDerivedFrom | prov:wasDerivedFrom |
| IsNewVersionOf | prov:wasRevisionOf |
| IsObsoletedBy | prov:wasInvalidatedBy |
| IsVariantFormOf, IsIdenticalTo | prov:alternateOf |
| HasPart | prov:hadMember |
| Compiles | prov:hadPrimarySource |
| Other relations (IsPartOf, Requires, Cites and others) | nexus: predicates, or omitted when they carry no provenance meaning |
Record refs (<recordUni>@<recordVersion>, in legacy or NS-1 form) become prov:used entities. Each version is prov:specializationOf its record concept and prov:wasRevisionOf the previous version, so that the correction dependencies of a product form a graph that a correction replay can traverse. Legacy identifiers appear as nexus:legacy:<id> with nexus:legacyUni until a UNI is allocated.
Honesty
The profile describes; it does not assert truth, readiness or approval. legalState, claimCeiling and status are carried verbatim. A proprietary licence is stated as proprietary (STAC) or as the LicenseRef- string (DCAT) and is never mapped to an open licence.
Adoption
- An implementation that serves exports offers
format=stac,format=dcatandformat=provfor every catalogued artifact it publishes (NS-1 section 6). - An ingest that allocates NS-3 record UNIs keeps the legacy
recordUnias its key and reportsALLOCATED,NOT_REQUESTEDorUNAVAILABLE(NS-3 section 4). The observation refNXS-GRX-OB-<ISO3>-<serial>@<recordVersion>is what a product cites in its correction dependencies and what its PROV-O bundle turns intoprov:used.
Changes between versions
One published version is available (0.1.0); a comparison between versions is shown once a second version is published.
Clause numbers follow the sections of the document; rule identifiers () are stable anchors. With script enabled, each clause and rule has a permalink and a machine-readable view (YAML and JSON), and the j and k keys move between clauses.
Programme areas that list NS-3b
14 programme areas list NS-3b.
- Water risk standardsTierNexus domainsStatusplanned
- Food and agriculture risk standardsTierNexus domainsStatusplanned
- Biodiversity and nature risk standardsTierNexus domainsStatusplanned
- Climate risk standardsTierNexus domainsStatusplanned
- Atmosphere and weather hazard standardsTierHazard and threat familiesStatusplanned
- Water systems hazard standardsTierHazard and threat familiesStatusplanned
- Solid Earth hazard standardsTierHazard and threat familiesStatusplanned
- Data and datasetsTierCross-cutting capabilitiesStatusplanned
- Geospatial and Earth observationTierCross-cutting capabilitiesStatusplanned
- Provenance and evidenceTierCross-cutting capabilitiesStatusplanned
- GCRI Canada evidence pathwayTierReadiness pathwaysStatusplanned
- Geophysical hazard standardsTierHazard and threat familiesStatusplanned
- Hydrometeorological hazard standardsTierHazard and threat familiesStatusplanned
- Oceans and coasts risk standardsTierHazard and threat familiesStatusplanned
Recent research on NS-3b
Recent peer-reviewed articles, preprints, datasets and reports on the subject of this standard, retrieved at the time of reading from open scholarly metadata services (OpenAlex, Crossref, DataCite, Zenodo, arXiv, Europe PMC, OpenAIRE Graph) with search terms composed from the registry. Each work is listed with its authors, venue, year, type, open-access status and licence, and links to its DOI or landing page. Sources not yet enabled for live display on this site are listed for reference and are not queried.
Search termsSpatioTemporal Asset Catalog; DCAT; PROV-O; metadata profile; provenance metadata; geospatial metadata; Schema.org vocabulary; RFC 7946 The GeoJSON Formatcombined with: metadata; data; provenance; geospatialDerived from the subject of the standard and its rules, and the external standards of its crosswalk domains.
- OpenAlexlisted for reference; not queried
- Crossreflisted for reference; not queried
- DataCitelisted for reference; not queried
- Zenodolisted for reference; not queried
- arXivlisted for reference; not queried
- Europe PMClisted for reference; not queried
- OpenAIRE Graphlisted for reference; not queried
No source is enabled for live display on this site yet: the sources are listed for reference and none is queried. Once the publisher of record enables a source after its terms are reviewed, recent works are listed here. Metadata and links only: title, authors, venue, year, type, open-access status and licence as each source records them; works are listed for orientation, not reviewed or endorsed.
NS-3b in the standards repository
The text, schemas, machine-readable files, registry rows, tests and history behind NS-3b, on the main branch of the canonical repository. Text, registry, schemas and catalog are CC BY 4.0; tools and tests are Apache-2.0.
Source text
| File | What it holds | Links |
|---|---|---|
standards/NS-3b-dataset-and-product-metadata-profile.md | NXS-STD-SW-000005 | Raw · History · Suggest an edit |
standards/INDEX.md | status and document of every standard | History |
Machine-readable files
| File | What it holds | Links |
|---|---|---|
catalog/artifact-catalog.yaml | catalog records · 2 mentions | First mention, line 127 |
Registry rows
| File | What it holds | Links |
|---|---|---|
registry/ecosystem-coverage.yaml | Nexus ecosystem coverage register (programme B corpus read) · 71 rows or mentions | Line 106 |
registry/standard-packages.yaml | Standard packages - one package per external open standard on nexustandards.com · 14 rows or mentions | Line 53 |
registry/subsites.yaml | Nexus Standards subsites - the systemic architecture of nexustandards.com · 11 rows or mentions | Line 37 |
registry/open-standards-stack.yaml | Open-standards and open-source stack under the UNI · 4 rows or mentions | Line 56 |
registry/external-standards.yaml | External standards landscape that the Nexus Standards cite, crosswalk, profile, adopt or extend · 3 rows or mentions | Line 1242 |
registry/review-investigations.yaml | Circulation for technical review and comment, and the technical review areas · 1 row or mentions | Line 58 |
Tests and validators
| File | What it holds | Links |
|---|---|---|
tools/build-risk-standards.mjs | tool or validator | Line 97 |
tools/build-site-pages.mjs | tool or validator | Line 292 |
tools/validate.mjs | tool or validator | Line 150 |
Change history
| File | What it holds | Links |
|---|---|---|
| Commits to the text | every change to the text | · |
CHANGELOG.md | notable changes, by version | · |
release/manifest.json | release manifest with file digests | in-toto statement |
| Releases | tagged releases of the repository | · |
Propose a change
| File | What it holds | Links |
|---|---|---|
| Open a proposal on NS-3b | issue form: target, kind, rationale (NS-13) | Template |
| Issue form: comment | issue form | Template |
| Issue form: errata | issue form | Template |
| Issues that mention NS-3b | open and closed | · |
| Pull request template | what a change must carry: target, kind, rationale, validation | · |
CONTRIBUTING.md | pull requests, sign-off and checks | · |
GOVERNANCE.md | how registry codes and texts change | · |
How NS-3b is developed, and how to take part
NS-3b is developed in the open under NS-13 (the stages and gates of NS-13). Working groups draft, councils decide the reserved matters, and anyone may propose a change, comment, submit an implementation report, object or appeal, without membership or fee.
- Who decides what: the decision-rights matrix.
- The process: stages, gates, review windows and appeals.
- Open gateways and calls: how to propose, comment, join a working group or request activation.
- Develop a standard: the development track and the lifecycle of each standard.
- NS-13 in the canonical repository.
Relation to external standards
NS-3b relates to external standards by identifier, clause number and URL (NS14-R1), and directs the reader to the issuing body.
Recent research and sources
Peer-reviewed articles, preprints, reports and datasets on the subject of this standard, retrieved at the time of reading from open scholarly metadata services (OpenAlex and Crossref) and listed with authors, venue, year, type and access status, with a link to each work. Curated references and related standards are listed first; recent works matched by subject follow and are listed for orientation.
Curated references
- The FAIR Guiding Principles for scientific data management and stewardship
Scientific Data · 2016 · Peer-reviewed - The CARE Principles for Indigenous Data Governance
Data Science Journal · 2020 · Peer-reviewed - FAIR Data Maturity Model: specification and guidelines
Research Data Alliance · 2020 · Official publication - Data Catalog Vocabulary (DCAT) - Version 3
W3C · 2024 · Standard - Geodesic Discrete Global Grid Systems
Cartography and Geographic Information Science · 2003 · Peer-reviewed - The Australian Geoscience Data Cube - Foundations and lessons learned
Remote Sensing of Environment · 2017 · Peer-reviewed - Building an Earth Observations Data Cube: lessons learned from the Swiss Data Cube on generating Analysis Ready Data
Big Earth Data · 2017 · Peer-reviewed - OGC API - Features
OGC · 2019 · Standard
Related standards and frameworks
- Schema.org vocabulary
Schema.org Community Group (W3C) - SpatioTemporal Asset Catalog (STAC) specification
STAC community; OGC Community Standard 25-004 - W3C Verifiable Credentials Data Model v2.0
W3C Verifiable Credentials Working Group - Sigstore (Cosign, Fulcio, Rekor)
OpenSSF (Linux Foundation); graduated project March 2024 - OGC GeoPackage Encoding Standard
Open Geospatial Consortium - W3C Data Catalog Vocabulary (DCAT) - Version 3
W3C Dataset Exchange Working Group - Croissant: A Metadata Format for ML-Ready Datasets
MLCommons Croissant Working Group - in-toto Attestation Framework
in-toto project (CNCF)
Search terms, derived from the subject of the standard and its rules: SpatioTemporal Asset Catalog; DCAT; PROV-O; metadata profile; provenance metadata; geospatial metadata; combined with: metadata; data; provenance; geospatial. With JavaScript enabled, recent works matching these terms are listed from OpenAlex and Crossref.
Risk Academy courses and disciplines
2 courses and 4 disciplines of Risk Academy (risksacademy.com) that teach the knowledge and methods of NS-3b. Each course lists its level, stream and learning hours.
Courses
Disciplines
The correspondence between courses, disciplines and the Nexus Standards is maintained with Risk Academy and is subject to its academic review.
Programmes, tracks and courses for this standard
GCRI Canada and Risk Academy work on the subject of NS-3b in distinct roles (research and evidence; education and training). Each entry states why it corresponds and the step it offers; each institution sets its own terms of participation.
Research and evidence
GCRI Canada
Research programmes that produce the observations, models and assessments these records describe.
Space and Earth ObservationStudies spatial-temporal evidence and its metadata.Apply to this programme Data and ComputeEngineers reproducible pipelines.Apply to this programme therisk.globalAll programmes of GCRI CanadaEducation and training
Risk Academy
Courses and disciplines that teach the knowledge and methods practitioners need to apply these standards.
Earth Observation and GIS for RiskRAT-201 · Introductory · 22 learning hoursMaps, satellites, terrain and open data for hazard and exposure analysis, with four hands-on labsTake this course Technology and DataRAT-204 · Intermediate · 19 learning hoursManaging risk data, AI, digital infrastructure and technology risk responsiblyTake this course All courses and disciplinesListed in the education and training section of this pageQuestions and answers.
What is the status of NS-3b?
What does applying NS-3b establish?
How is a change to NS-3b proposed?
Contribute to Nexus Reports from this page.
Nexus Reports is the Consortium's quarterly publication. What you know about this subject can become evidence, a case or a correction in the next edition, credited to you and published under CC BY 4.0 where it is your own work.
- GatewayGW-STDSend it from this pageEvidence, a correction, a case, a method, a review, a translation or profile input. It arrives tagged with this page, so the editor who owns it receives it.
- ZenodoOpen depositDeposit it and submit to the communityPublish your own record on Zenodo with your ORCID iD, then submit it to the Nexus Reports community. Curators review it there; the DOI stays yours.
- Nexus ReportsGCRISee every way to contributeThe contribution types, how each is reviewed, what credit you receive, the licence and what is never accepted.
Never send personal data, sensitive infrastructure detail or anything you have no right to share. A contribution is reviewed before use; sending it confers no authorship or editorial rights, and sponsorship never buys a finding.
The same subject across the Consortium.
Around the Nexus Standards.
Take part in the standards.
Governments, regulators, standards bodies, industry, academia and communities are invited to shape the catalogue ahead of its first official release, targeted for 2030: comment on a draft, propose a change, join a working group or host a field exercise.
Status and use. The Nexus Standards are proposed standards developed through an open process under NS-13 and published for voluntary use; they do not constitute certification, accreditation or regulatory approval, and adoption remains a decision of the Global Standards Council and, in each country, of its National Standards Council. A UNI (Unique Nexus Identifier) identifies an artifact; it does not certify it. Names of standards bodies and their standards belong to their stewards and are used only to identify the documents; no text of an external standard is reproduced here. Nexus Standards is not affiliated with, endorsed by or certified by any standards body named here.
Licences: CC BY 4.0 for standards text, registries, schemas and data; Apache-2.0 for reference code. External standards are cited by name, number and link under their own licences. Third-party data, libraries and fonts keep their own licences: see Third-party notices.