Geospatial Incubator Group Charter

The mission of the Geospatial Incubator Group, part of the Incubator Activity, is to begin addressing issues of location and geographical properties of resources for the Web of today and tomorrow, by taking a concrete step to update the W3C GEO vocabulary, laying the groundwork for a more comprehensive geospatial ontology, and formulating a proposal for a W3C Local Web working group to develop recommendations to further the Local Web.

Join the Geospatial Incubator Group.

End date 23 Jun 2007
Confidentiality Proceedings are public
Initial Chair Joshua Lieberman (jlieberman@traversetechnologies.com)
Sponsoring Members
Usual Meeting Schedule Telcons: Fortnightly
Ftf: 3-4 per year (more on meetings)

Scope and Objectives

Location and geographical properties of resources has always been something of a dilemma for the World Wide Web, which has served so well to unlink the global identity of a resource from its physical location on the globe. One of the Web's greatest values is its capacity for enabling the growth of communities which are not constrained by distance and geography. Nonetheless, physical location is at least an essential property if not a part of the identity of any real entity. When appropriate, the Local Web of resources identified by location and geography is an essential aspect of Web discovery and communication.

Issues in geographical representation are many and often parallel those in the Web as a whole, from resource identifiers to machine-readable semantics. Just as there are both physical (IP) and conceptual (domain namespace) locators on the World Wide Web, there are physical (latitude-longitude coordinates and street addresses) and conceptual (placenames and political divisions) locators on the Local Web. Geospatial concepts and relationships are at once as possible and difficult to define with formal semantics as those which express any other resource meaning. Geospatial aspects of progress from the Web of text and tags to the Semantic Web are just as challenging and important.

There are, however, unique aspects to the geospatial representation of information which merit special attention in the advancement of the Web as a whole. The map is not the terrain; a geographic coordinate pair is only a terse representation of a geographical entity. Something as simple as a geotagged Web page “a representation of a representation“ raises unresolved semantic, syntactic, and engineering issues which have until now hindered full development of the Local Web. Yet another set of issues is raised by the fact that it is not always desirable or “safe“ for world to know where a resource lives. Some of the gateways from the World Wide Web to the Local Web require gates and gatekeepers.


The Geospatial XG has three objectives which address needs of the Local Web:


The W3C Semantic Web Interest Group formulated in 2003 an initial RDF vocabulary for location . The opportunities presented by RSS and Atom for geolocating lightweight information formats, together with advances in standardization of location encoding from the Open Geospatial Consortium (OGC) have prompted an update of this vocabulary in the form of GeoRSS. This update both extends the expressiveness of the initial vocabulary and places it in a firmer context of OGC and ISO work on geographic information.

Geospatial Ontology

As enabling technologies for the Semantic Web have developed, such as RDF, OWL, SPARQL, and SWRL, much work has been done to build the ontologies required for expressing the common elements of disparate knowledge artifacts. This is particularly true in the realm of geospatial and temporal concepts and relationships, yet the work has not yet reached a level of either consensus or actionability which would allow it to be the basis of knowledge interoperability. In other words, it is not yet ready to support the functionality of a Geospatial Semantic Web, where the geographic properties of knowledge resources can be expressed, discovered, acted upon by machines, and understood by diverse communities.

W3C Local Web Working Group

A latitude-longitude coordinate pair may be the shortest path to an initial resource geo-identity, but issues of location and geography permeate virtually all areas in which the World Wide Web of physical entities is becoming richer and more functional. The emergence of geographic information science disciplines and standardization efforts by many organizations worldwide have shown how important it is to get geography right. A W3C Local Web Working Group would be the right place to develop the vocabularies, ontologies, rules, and practices to do this. A subsequent or adjacent Interest Group could potentially augment this effort by representing a Local Web perspective in other W3C activities. A Geospatial XG is proposed in part to undertake this sort of planning and charter development.

Use Cases

The demand for flexible and powerful geospatial enablement of the Web is exemplified in the following use cases.

Use case 1: Find stuff nearby

Web publishers have tagged their HTML content with a variety of standard geographic properties, including absolute geometries, well-known placenames, street addresses, and geospatial domain addresses. Internet search engines have translated and indexed these geospatial properties according to location and content relationship. Web user Harold shares his location in a search request for available sports-related resources within 15 minutes travel time. An initial search for nearby transportation uncovers roads, trails, and a commuter rail line which define a travel time envelope. A second search finds a number of Web pages which refer to sports-related resources within the envelope. The resources include a sports bar within walking distance and the segment of a lake shore recreation area within driving distance. It does not include the travel blog of Maude, a former professional triathlete sitting at a cafe nearby, because the current blog entry is tagged by a geospatial domain name which can only be resolved to an absolute location by requests from an identified group of friends or emergency response organizations. Since the local time of the search is 9:15 pm and the lake park closes at 9 pm, the home page of the sports bar is listed first.

Use case 2: News of the world

Web news services provide their stories in the form of GeoRSS feeds. Sven at UNHCR is tasked with monitoring both new and known areas for refugee issues. He utilizes an aggregator service which plots on a world map the locations of public news items which also reference refugee issues. Sven's GeoRSS client also allows him to visualize private news feeds of current UNHCR activities and available relief resources. Sven is able to use several map visualization techniques to look at the combined distribution and nature of events referenced by the public and private news feeds. Clicking on a particular entry, he brings up that entry's source news story or internal report. Once he has identified a significant collection of events and commented on it, he saves a Web map context document (WMC) with GeoRSS annotations, specific Web Map Server requests, and general map tile references to his weblog. UN colleagues who subscribe to Sven's weblog feed receive a GeoRSS news item outlining his area of interest and follow it to bring up the news map he has constructed for them.

Use case 3: New knowledge from old geography

A new educational initiative has published to the Web in geo-enabled form the results of many years of scientific and cultural study related to Breechcloth National Monument. Joe, a Park Service volunteer organizes virtual tours by publishing Web pages which reference those Web resources related to a particular theme along popular hiking trails. Mary, a park visitor, is able to assemble her own personal tours by drawing a path of interest on a visitor center kiosk and searching for resources of a particular time and theme of interest. Since the wireless connectivity in the Monument is not yet widespread, she downloads the tour into her GPS-equipped phone to take along. Her personal tour includes geoweblog entries and photos posted by visitors two years previous at a time when heavy rains caused many unusual plants to bloom along her chosen (and now quite dusty) path. Another tour resource is a page describing the site of a rare archaeological find. Mary is able to view the photographs and drawings on her phone, but the public page is only tagged with a rather large bounding box to reduce the risk of a visitor finding and damaging the site itself. Park personnel and researchers have access to a separate page tagged with the actual GPS coordinates of the site.

Use case 4: Follow the geography

Alice is preparing a grant proposal to support a new recycling initiative in Nepotist County. She wants to research county-level recycling programs worldwide. Firing up her semantic search client, she initiates a SPARQL query which includes among others the concepts of "county", "spatialScaleOf", and "recycling". Referencing a geospatial ontology, the query agent infers further geospatial concepts such as county instances and the names of county equivalents such as "parish" within the state of Louisiana. Inferred queries are passed on to other query agents which resolve county locations and synonyms, as well as concepts related to "recycling" such as "waste disposal", "sanitation", and "reuse". Filter agents reason on "spatialScaleOf" to eliminate discovered knowledge which is too limited in scale. Semantic similarity analysis finally returns to Alice information about a recycling program only two counties over which is a good model for her proposal but has been sparsely documented as "regional resource recovery". The query agent also processes her personal context with the query and returns unexpected references to two foundations with new programs to fund combined recycling and clean government initiatives.

Use case summary

These use cases serve to illustrate that tagging Web pages with latitude-longitude coordinates is only a starting point to the geospatial representations, relationships, resources, and interfaces which will form the functional basis of the Local Web.


  1. An updated, harmonized GEO vocabulary.

  2. Report of initial Geospatial Ontology recommendations.

  3. A draft Local Web Working Group charter.

The objectives of the XG involve mainly the assembly and reconciliation of materials which have already been developed in a number of forums; it is expected that they can be accomplished in 6-8 months.


The Open Geospatial Consortium, Inc (OGC) is an international industry consortium of 310 companies, government agencies and universities participating in a consensus process to develop publicly available model, interface and encoding specifications for geospatial information. OpenGIS® specifications support interoperable solutions that "geo-enable" the Web, wireless and location-based services, and mainstream IT. OGC interoperability initiatives help members to develop new methods of distributed Web computing which would not be possible without agreement on how to represent, exchange, and operate on geographic concepts. Versions of many OGC specifications have subsequently been developed through collaborative agreement into ISO standards.


All technical work is on a public mailing list public-xg-geo@w3.org (archive) and Web pages. The mailing list will provide an important part of the communication both internally and externally.

The group's Member-only list is member-xg-geo@w3.org (archive)

Information about the group (deliverables, participants, face-to-face meetings, teleconferences, etc.) is available from the Geospatial Incubator Group home page.

Decision Policy

This Incubator Group makes decisions by consensus, manages dissent and maintains standing of its participants according to the W3C Process Document.

Patent Policy

This Incubator Group provides an opportunity to share perspectives on the topic addressed by this charter. W3C reminds Incubator Group participants of their obligation to comply with patent disclosure obligations as set out in Section 6 of the W3C Patent Policy. While the Incubator Group does not produce Recommendation-track documents, when Incubator Group participants review Recommendation-track specifications from Working Groups, the patent disclosure obligations do apply.

Incubator Groups have as a goal to produce work that can be implemented on a Royalty Free basis, as defined in the W3C Patent Policy.

For more information about disclosure obligations for this group, please see the W3C Patent Policy Implementation.


In an effort to minimize costs, face to face meetings will be co-located with other meetings that a significant number of participants are attending. Examples include planned spatial ontology workshops in May and June, the SeBGIS'06 workshop in October, as well as the Terra Cognita workshop at ISWC'2006 in November.

Input and Reference Materials

http://blogs.law.harvard.edu/tech/rss and http://web.resource.org/rss/1.0/

About this Charter

This charter for the Geospatial Incubator Group has been created according to the Incubator Group Procedures documentation. 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.

Joshua Lieberman <jlieberman@traversetechnologies.com>

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