Spatial Data on the Web Interest Group Charter

The group is now closed. Its work is continued in the Spatial Data on the Web Working Group.

Spatial information is of high value and importance in almost all data on the Web. As well as obvious use cases such as cartography and Earth sciences, events happen at a defined location, news stories affect a defined region, and, in a biomedical research lab, pathogens affect defined regions of tissue. Technologies like augmented reality and the Internet and Web of Things all depend on location. Members of OGC and W3C have defined sets of technologies that underpin (geo)spatial information systems and the Web respectively but both stand to benefit from direct cooperation, increasing the value of data and the power of applications that consume it.

The mission of the Spatial Data on the Web Interest Group is to:

The Spatial Data on the Web Interest Group is a W3C entity matched by a sub-committee of OGC's Technical Committee. Collectively, the two comprise the Joint W3C/OGC Organizing Committee, the JWOC.

Join the Spatial Data on the Web Interest Group.

Start date 05 October 2017
End date 30 June 2021
Chairs Linda van den Brink, Geonovum
Jeremy Tandy, Met Office
Team Contacts Ted Guild (0.1 FTE)
Meeting Schedule Teleconferences: 1-hour calls will be held monthly
Face-to-face: The IG will meet during the W3C's annual Technical Plenary week and during one of OGC's four annual Technical Committee meetings.


The Spatial Data on the Web IG is scoped to realize the W3C side of the Joint W3C/OGC Organizing Committee (JWOC). The JWOC exists to facilitate direct cooperation between the spatial information and Web communities, allowing each to benefit from the other's data, technologies and methods. The JWOC will publish joint work where appropriate and may recommend the creation of formal standards-defining working groups where necessary in one or both standards development organizations.

Out of Scope

The Spatial Data on the Web Interest Group is only concerned with areas where it is in the interests of both OGC and W3C to collaborate.

Success Criteria

The SDW IG is the forum for discussion of further implementation experience for the three SDW Working Group Notes listed in Deliverables. To be successful, the IG will publish updates to one or more of those Notes plus additional best practice guidance within the charter period.

Each specification should contain a section detailing any known security or privacy implications for implementers, Web authors, and end users.


More detailed milestones and updated publication schedules are available on the group publication status page.

Existing W3C/OGC specifications

The Interest Group will adopt and maintain the existing joint W3C/OGC non-normative specifications listed below:

Spatial Data on the Web Best Practices

The Best Practices Note will be updated, corrected and expanded in line with community feedback on its use and recommendations.

RDF Data Cube extensions for spatio-temporal components

This Note is expected to need maintenance over the course of the IG's charter period, taking into account further experience of its use. An extension to cover data tiling will be considered.

Expected completion: [Q4 2018]

Publishing and Using Earth Observation Data with the RDF Data Cube and the Discrete Global Grid System

As with QB4ST, this Note is expected to need maintenance over the course of the IG's charter period, taking into account further experience of its use. An extension to cover data tiling will be considered.

Expected completion: [Q4 2018]

Time Ontology in OWL

This is a joint W3C Recommendation/OGC Standard for which the JWOC will handle any errata arising but for which no further work is envisaged.

Semantic Sensor Network Ontology (SSN)

This is a joint W3C Recommendation/OGC Standard for which the JWOC will handle any errata arising. The Interest Group may consider updates to the document, to be published in a separate Note. It is noted that work on SSN within the Spatial Data on the Web Working Group uncovered some potential improvements to OGC Abstract Topic 20 (Observations and Measurements), so a revision of AS 20 (and ISO 19156) may also be triggered within the context of the Interest Group.

New W3C/OGC specifications

The Interest Group will develop the following new joint W3C/OGC non-normative specifications:

Statistical Data on the Web Best Practices

Like the Spatial Data on the Web Best Practices, this Note will be a specialization of the more general Data on the Web Best Practices Recommendation, offering guidance on sharing statistical data.

Expected completion: [Q2 2019]

SSN Primer

A Primer to explain how best to use the SOSA and SSN vocabularies.

Expected completion: [Q2 2018]

Sensors & Observations Note

An overview of the standards landscape related to sensors and observations that explains the scope of each of these standards, their application to practical use cases and mechanisms by which they may be combined.

Expected completion: [Q2 2018]

Describing moving objects

Describing trajectories and paths of moving objects requires a different approach to describing static ones. The Interest Group will consider how best to support Web applications that generate or use data concerning moving objects. Use cases include transportation, tourism, migration, location-based services, travel blogs and wildlife tracking.

Expected completion: [Q2 2019]

In addition, the Interest Group will assess the readiness of CoverageJSON for formal standardization. CoverageJSON is described, but not defined, in a Note published by the Spatial Data on the Web WG. CoverageJSON is a data format representing coverage data, such as Earth observation data, in JSON. The IG will monitor and encourage further development of the specification with a view to proposing a charter for a future Standards Working Group for its formal definition.

Subject to capacity and demand, the Interest Group may develop further vocabularies, to be published as Notes.


  • October 2017: First teleconference.
  • November 2017: First face-to-face meeting (TPAC), leading to new iterations of QB4ST and EO-QB.
  • December 2017: FPWD Stat BP, SSN Primer and Moving Objects.
  • June 2018: Updates on all documents, SSN Primer and Sensors & Observations Note complete.
  • December 2018: All documents except Stat BP and Moving Objects completed.
  • July 2019: Stat BP and Moving Objects completed. Assessment of future work priorities
  • December 2019, decision on rechartering


For all specifications, this Spatial Data on the Web Interest Group will seek horizontal review for accessibility, internationalization, performance, privacy, and security with the relevant Working and Interest Groups, and with the TAG where appropriate.

Additional technical coordination with the following Groups will be made, per the W3C Process Document:

Relationship with OGC

In collaboration with the W3C, the Open Geosptial Consortium, OGC, will create a sub-committee of its Technical Committee subject to its usual practice and rules of membership. This will be a RAND-Royalty Free Standards Working Group according to section 3.2.2 of OGC's 2008 Intellectual Property Rights Policy (PDF) to ensure compatibility with W3C's Patent Disclosures. Formally, each group will have its own charter and operate under the respective organization's rules of membership, however, the 'two groups' will work together very closely as the Joint W3C/OGC Organization Committee, JWOC, and create a set of common outputs as set out above that will be jointly branded.

As is now common practice, the W3C group will work in public, i.e. it will use a publicly visible mailing list and wiki, and the editor's drafts of its documents will be publicly visible (e.g. on GitHub). To enable write access to these facilities, unless there are specific reasons to the contrary, members of the OGC WG who do not represent W3C member organizations will be granted Invited Expert status, with all obligations and privileges, in the JWOC but without access to member-only resources. OGC-only members will be strongly encouraged to become members of W3C and vice-versa.

The JWOC chairs will represent organizations that are members of both standards bodies and, wherever possible, this will also be true of document editors.

W3C Groups

Web of Things Interest Group and Working Group
The Web of Things is heavily dependent on location data. Cooperation and interoperability of specifications is essential.
Dataset Exchange Working Group
Spatial Data has specific needs for data description, such as coordinate reference system, granularity. These must be taken into account by the DXWG.
Semantic Statistics Community Group
The Statistical Data on the Web Best Practices deliverable will not be restricted to geospatial statistics data. The Spatial Data on the Web Interest Group expects to maintain a close liaison with the Semantic Statistics Community Group to gather feedback and contributions from organizations publishing open data such as National Statistics Offices.

OGC Groups

Most working groups operating at OGC have a scope that may intersect with topics of interest discussed in the Spatial Data on the Web Interest Group. The Interest Group expects to liaise with OGC groups as needed, and more specifically with:

Augmented Reality Markup Language (ARML) SWG
Linking the W3C and OGC work on virtual, augmented and mixed reality.
Metadata DWG (DCAT sub-group)
Linking the W3C and OGC work on dataset description.
Moving Features SWG
This WG has particular relevance to the Moving Objects deliverable.
SensorThings SWG
Linking work on SSN in W3C with the OGC SensorThings API.
Sensor Web Enablement (SWE) DWG
Linking work on SSN in W3C with the open interfaces for sensor web applications developed at OGC.
Web Coverage Services (WCS) SWG, Web Feature Services (WFS) / Filter Encoding Service (FES) SWG, Web Mapping Service (WMS) SWG
These Working Groups develop technologies that will likely be discussed within the Spatial Data on the Web Interest Group.

External Groups

The community and standards around the European INSPIRE Directive are an important reference point for the Working Group.


To be successful, this Interest Group is expected to have 10 or more active participants for its duration, including representatives from both the Web and geospatial communities (inasmuch as they differ), as well as active Editors for each specification. The Chairs and specification Editors are expected to contribute half of a working day per week towards the Interest Group. There is no minimum requirement for other Participants.

The group encourages questions, comments and issues on its public mailing lists and document repositories, as described in Communication.

The group also welcomes non-Members to contribute technical submissions for consideration upon their agreement to the terms of the W3C Patent Policy.


Technical discussions for this Interest Group are conducted in public: the meeting minutes from teleconference and face-to-face meetings will be archived for public review, and technical discussions and issue tracking will be conducted in a manner that can be both read and written to by the general public. Working Drafts and Editor's Drafts of specifications will be developed on a public repository, and may permit direct public contribution requests. The meetings themselves are not open to public participation, however.

Information about the group (including details about deliverables, issues, actions, status, participants, and meetings) will be available from the Spatial Data on the Web Interest Group home page.

Spatial Data on the Web Interest Group teleconferences will focus on discussion of particular specifications, and will be conducted on an as-needed basis.

This group primarily conducts its technical work on the public mailing list (archive) and using the GitHub issue tracker. The public is invited to review, discuss and contribute to this work.

The group may use a Member-confidential mailing list for administrative purposes and, at the discretion of the Chairs and members of the group, for member-only discussions in special cases when a participant requests such a discussion.

Decision Policy

This group will seek to make decisions through consensus and due process, per the W3C Process Document (section 3.3). Typically, an editor or other participant makes an initial proposal, which is then refined in discussion with members of the group and other reviewers, and consensus emerges with little formal voting being required.

However, if a decision is necessary for timely progress, but consensus is not achieved after careful consideration of the range of views presented, the Chairs may call for a group vote, and record a decision along with any objections.

To afford asynchronous decisions and organizational deliberation, any resolution (including publication decisions) taken in a face-to-face meeting or teleconference will be considered provisional. A call for consensus (CfC) will be issued for all resolutions (for example, via email and/or web-based survey), with a response period from one week to 10 working days, depending on the chair's evaluation of the group consensus on the issue. If no objections are raised on the mailing list by the end of the response period, the resolution will be considered to have consensus as a resolution of the Interest Group.

All decisions made by the group should be considered resolved unless and until new information becomes available, or unless reopened at the discretion of the Chairs or the Director.

This charter is written in accordance with the W3C Process Document (Section 3.4, Votes), and includes no voting procedures beyond what the Process Document requires.

Patent Disclosures

The Interest Group provides an opportunity to share perspectives on the topic addressed by this charter. W3C reminds Interest Group participants of their obligation to comply with patent disclosure obligations as set out in Section 6 of the W3C Patent Policy. While the Interest Group does not produce Recommendation-track documents, when Interest Group participants review Recommendation-track specifications from Working Groups, the patent disclosure obligations do apply. For more information about disclosure obligations for this group, please see the W3C Patent Policy Implementation.


This Interest Group will use the W3C Software and Document license for all its deliverables.

About this Charter

This charter has been created according to section 5.2 of the Process Document. In the event of a conflict between this document or the provisions of any charter and the W3C Process, the W3C Process shall take precedence.

Charter History

Note:Display this table and update it when appropriate. Requirements for charter extension history are documented in the Charter Guidebook (section 4).

The following table lists details of all changes from the initial charter, per the W3C Process Document (section 5.2.3):

Charter Period Start Date End Date Changes
Initial Charter 5 October 2017 31 December 2019
Charter Extension 26 September 2019 31 March 2020 none
Charter Extension 2 April 2020 30 September 2020 to recharter (Draft) as a Working Group
Charter Extension 30 September 2020 31 March 2021 continue to recharter (Draft) as a Working Group
Charter Extension 31 March 2021 30 June 2021 continue to recharter (Draft) as a Working Group