DRAFT Spatial Data on the Web Working Group Charter

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

W3C Members join the Spatial Data on the Web Working Group; OGC Members should contact the Chairs or Staff Contact to join the group.

This proposed charter is available on GitHub. Feel free to raise issues.

Start date [1 July 2021] (date of the "Call for Participation", when the charter is approved)
End date [@@ 2023 (two years from start date)]
Charter extension See Change History.
Chairs Linda van den Brink, Geonovum
Jeremy Tandy, Met Office
Team Contacts TBD (0.1 FTE)
Meeting Schedule Teleconferences: monthly, additional topic-specific calls may be held when the chairs choose to convene the group.
Face-to-face: the WG will meet during the W3C's annual Technical Plenary week and during one of OGC's four quarterly Member Meetings.


The Spatial Data on the Web WG will:

Out of Scope

The Spatial Data on the Web Working Group will only produce deliverables where it is in the interests of both OGC and W3C to collaborate.


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

Draft state indicates the state of the deliverable at the time of the charter approval. Expected completion indicates when the deliverable is projected to become a Recommendation, or otherwise reach a stable state.

Normative Specifications

The Spatial Data on the Web Working Group is overseeing long term maintenance for the W3C and OGC normative specifications and best practices delivered by the Spatial Data on the Web Working Group.

Time Ontology (revision)
OWL-Time is an OWL-2 DL ontology of temporal concepts, for describing the temporal properties of resources in the world or described in Web pages. The revision includes four new temporal relations (disjoint, equals, hasInside, and notDisjoint) and the means to represent multiple time instants and intervals (aka temporal aggregates).

Draft state:Candidate Recommendation

Expected completion: Q4 2022

Semantic Sensor Network Ontology
The Semantic Sensor Network (SSN) ontology is an ontology for describing sensors and their observations, the involved procedures, the studied features of interest, the samples used to do so, and the observed properties, as well as actuators. Included in this specification is a core ontology called SOSA (Sensor, Observation, Sample, and Actuator).

Draft state:Recommendation

Expected completion:(maintenance)

Extensions to the Semantic Sensor Network Ontology
This ontology provides extensions to the SSN ontology to enable linking directly to the ultimate feature-of-interest for an act of observation, sampling, or actuation and provide homogeneous collections of observations.

Draft state:Working Draft

Expected completion: Q4 2022

Other Deliverables

Spatial Data on the Web Best Practices
This document advises on best practices related to the publication of spatial data on the Web; the use of Web technologies as they may be applied to location.

Draft state:Best Practices

Expected completion: Q4 2021

WebVMT: The Web Video Map Tracks Format
This W3C Note / OGC Discussion Paper describes the Web Video Map Tracks Format (WebVMT) which is an enabling technology used for marking up external map track resources in connection with the HTML <track> element and making geotagged video more accessible on the Web. WebVMT files provide map presentation and annotation synchronised to video content, including animation support, and more generally any form of geolocation data that is time-aligned with audio or video content.

Draft state:Editors Draft

Expected completion: Q4 2022

The Responsible Use of Spatial Data
This W3C Note / OGC Discussion Paper highlights some of the unique characteristics of spatial data within the broader realm of ethical use of data.

Draft state:First Public Working Draft IG Note

Expected completion: Q4 2021

Other non-normative documents may be created such as:

  • Use case and requirement documents;
  • Test suite and implementation report for the specifications being maintained;
  • Primer or Best Practice documents to support web developers when designing applications;
  • OGC Discussion Papers;
  • OGC Technical Papers;
  • W3C Notes.

Success Criteria

In order to advance to Proposed Recommendation, each specification is expected to have at least two independent implementations of each of feature defined in the specification.

Each specification should contain separate sections detailing all known security and privacy implications for implementers, Web authors, and end users.

There should be testing plans for each specification, starting from the earliest drafts.

Each specification should contain a section on accessibility that describes the benefits and impacts, including ways specification features can be used to address them, and recommendations for maximising accessibility in implementations.

To promote interoperability, all changes made to specifications should have tests.


For all specifications, this Spatial Data on the Web Working Group will seek horizontal review for accessibility, internationalization, performance, privacy, and security with the relevant Working and Interest Groups, and with the TAG and the OAB. Invitation for review must be issued during each major standards-track document transition, including FPWD. The Spatial Data on the Web Working Group is encouraged to engage collaboratively with the horizontal review groups throughout development of each specification. The Spatial Data on the Web Working Group is advised to seek a review at least 3 months before first entering CR and is encouraged to proactively notify the horizontal review groups when major changes occur in a specification following a review.

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


The Spatial Data on the Web Working 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. This effort 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 Spatial Data on the Web WG will coordinate between OGC and W3C on shared interests and raise awareness of their complementary strengths (e.g. Web scale architecture, accessibility, privacy, internationalisation, geospatial expertise), and will monitor and liaise between groups from OGC and W3C.

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 Working 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.
Linked Building Data Community Group
The Linked Building Data Community Group brings together experts in the area of building information modelling (BIM) and Web of Data technologies to define existing and future use cases and requirements for linked data based applications and corresponding ontologies across the life cycle of buildings.
Linked Data for Accessibility Community Group
The Linked Data for Accessibility Community Group’s mission is to make accessibility information about buildings, services and routes easier to find — everywhere where people need it.
Automotive Working Group
The W3C Automotive Working Group is creating an in-vehicle application ecosystem normalizing a common data model for vehicle signals (fuel level, tire pressure..) and means to access them.
Automotive and Transportation Business Group
The Automotive and Transportation Business Group, soon to be renamed and relaunched as the Automotive and Transportation Business Group has been exploring the use cases and challenge of off-boarding vehicle information to the cloud and how this information fits within the broader transportation sector. It is taking a data centric focus and working on an ontology for vehicle signals and coordinating effort with OGC, SDWWG, ISO SmartCities, ISO Intelligent Transportation Systems and others on transportation related ontologies.
Accessible Platform Architectures Working Group
The Accessible Platform Architectures Working Group is to ensure W3C specifications provide support for accessibility to people with disabilities. The group advances this mission through review of W3C specifications, development of new specifications and technical support materials, collaboration with other Working Groups, and coordination of harmonized accessibility strategies within W3C.
Maps For HTML Community Group
The Maps For HTML Community Group seeks to establish maps as a first class object on the web similar to the Media and Entertainment activity did for video, allowing for layering and customizing data on a scale not currently possible with proprietary online map offerings.
Augmented Reality Community
The Augmented Reality Community Group is an open forum for collaborative discussions about the intersection of Augmented Reality and the Web.
Immersive Web Working Group and Community Group
These groups helps bring high-performance Virtual Reality (VR) and Augmented Reality (AR) (collectively known as XR) to the open Web.
Media and Entertainment Interest Group
The Media and Entertainment Interest Group provides a forum for media-related technical discussions and includes the Media Timed Events Task Force, which is relevant for WebVMT coordination.

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 Working Group. The OGC Architecture Board (OAB), comparable to the W3C Technical Advisory Group (TAG) will provide high level guidance to the Spatial Data on the Web Working Group. The Working Group expects to liaise with OGC groups as needed, and more specifically with:

GeoPose 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 and profiles.
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.
Observations and Measurements v2 SWG
Linking work on SSN in W3C with the data model for Observations and Measurements at OGC.
OGC API Standards Working Groups
These Working Groups develop the OGC API suite of Standards that will likely be discussed within the Spatial Data on the Web Working Group.
Mobile Location Services DWG
Linking the W3C and OGC work on location-aware mobile services.
GeoSemantics DWG
Linking the W3C and OGC work on semantics and linked data.


To be successful, this Spatial Data on the Web Working Group is expected to have 6 or more active participants for its duration, including representatives from the key implementors of this specification, and active Editors and Test Leads for each specification. The Chairs, specification Editors, and Test Leads are expected to contribute half of a working day per week towards the Working 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.

Participants in the group are required (by the W3C Process) to follow the W3C Code of Ethics and Professional Conduct.


Technical discussions for this Spatial Data on the Web Working 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 Working Group home page.

Most Spatial Data on the Web Working 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 public-sdwig@w3.org (archive) and on GitHub issues. 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 and 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 Spatial Data on the Web Working 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 Policy

This Working Group operates under the W3C Patent Policy (Version of 15 September 2020). To promote the widest adoption of Web standards, W3C seeks to issue Recommendations that can be implemented, according to this policy, on a Royalty-Free basis. For more information about disclosure obligations for this group, please see the W3C Patent Policy Implementation.


The Spatial Data on the Web Working Group will use the W3C Software and Document license, with copyright held by OGC and W3C. Published documents will be clearly marked as joint 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

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 05 October 2017 31 December 2019 none
Charter Extension 31 December 2019 31 March 2020 none
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
Rechartered 01 April 2021 31 March 2024

[description of change to charter, with link to new deliverable item in charter] Note: use the class new for all new deliverables, for ease of recognition.