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Standards: Key to VGI success

Mark Reichardt
President & CEO, Open Geospatial Consortium
[email protected]

Geospatial encoding and service interface standards, especially open standards, are essential elements in the success of VGI policies, initiatives and business schemes

Advances in positioning technologies, Web mapping, cellular communications, smart phones, sensor Webs, webcams and wiki-based collaboration have opened up opportunities for almost anyone, or anything, to become an active or passive producer of geospatial or location data. Commercially, Google Map Maker now provides citizens in more than 40 countries the ability to populate and update Google Maps road centreline and attribute data. Firms like Navteq (Nokia) and Tele Atlas (TomTom) use customer input to locate and qualify mapping errors and/or feature updates in their road network databases. Location-based marketing services such as Facebook Places and FourSquare depend on user input. Geolocated, internet-connected sensors become increasingly small, cheap, energy-efficient and easy to integrate into physical devices and digital systems.

It is important to keep in mind that we are just beginning to see the emergence of new kinds of location information flow from and between advancing digital technologies. The activities of businesses, citizens, consumers, researchers, non-governmental organisations and governments will evolve as we use these technologies to support productive activities and also as we struggle to counter the technologies' assaults on privacy, security, institutional continuity and the reliability of information.

Information moves by means of standards
Applications involving VGI and location information crowdsourcing ( depend on transfers of location data and also transfers of location information service queries and responses. For such transfers to take place, the data needs to be encoded in ways that digital systems can interpret it and the services need to provide known interfaces so that clients and servers can communicate queries and responses. Geospatial encoding and service interface standards, especially open standards, are thus essential elements in the success of VGI policies, initiatives and business schemes.

OGC standards
The OGC, working with many other information and communication technology (ICT) standards organisations, has produced and continues to produce standards that are relevant to VGI and crowdsourcing.The 37 existing OGC standards include, for example:

OGC KML: Google submitted KML (formerly Keyhole Markup Language) to the Open Geospatial Consortium (OGC) to be evolved within the OGC consensus process. KML makes it easy for users to "mashup" data records with map servers like Google Maps that display KML files.

OGC Open GeoSMS: The OGC Open GeoSMS standard provides developers with an extended short message service (SMS) encoding and interface to communicate location content between different LBS (locationbased service) devices or applications. Developers of Open GeoSMS provide a free, open source software development kit and the standard is used in various disaster management volunteer communications applications related to Sahana and Ushahidi.

GML profile of GEORSS: As RSS ("real simple syndication") and Atom become more prevalent as a way to publish and share information, it becomes increasingly important that location be described in an interoperable manner so that applications can request, aggregate, share and map geographically tagged feeds. GeoRSS was designed as a lightweight, community driven way to extend existing feeds with geographic information.

OGC City Geography Markup Language (CityGML) Encoding Standard: CityGML provides a common definition of the basic entities, attributes, and relations of 3D city models. This is important with respect to the cost-effective sustainable maintenance of 3D city models, allowing the reuse of the same data in different application fields. Researchers at Heidelberg University have shown how such models can be built and maintained with the help of VGI and crowdsourcing.

VGI-related OGC activities
Below are a few of the current areas of activity in the OGC, focused on OGC standards relevant to VGI and crowdsourcing:

Geosynchronisation: Geospatial content providers must increasingly collaborate with outside entities to collect new data and/or update their existing data holdings. A geosynchronisation service, deployed by a data provider, sits between data collectors and the features a data provider offers. It allows data collectors to submit new data or make modifications to existing features without directly affecting the features in the provider's data store(s) until validation has been applied, thus ensuring that the data published by the provider is of high quality. The OGC Geosynchronisation Service Standards Working Group (SWG) is developing a candidate OGC Geosynchronization Interface standard version 1.0.0.

Decision fusion – Object fusion: Decision fusion, in the context of the OGC's work, provides analysts an environment of interoperable services for situation assessment, impact assessment and decision support, based on information from multiple sensors, databases and people, perhaps via social networks. Though the focus of a recent OGC decision fusion study was on military intelligence, decision fusion is equally relevant to business intelligence, urban planning and many other domains.

WFS-G (Gazetteer): Geonames databases, called gazetteers, are an information resource for representing places, groups of people and cultures. The OGC WFS-G best practice paper describes the Gazetteer Service Application Profile of the OGC Web Feature Service Interface Standard.

RESTful Service Policy Standard Working Group and OGC GeoServices REST 1.0 candidate standard:
REST stands for "Representational State Transfer", a set of principles and constraints for Web computing that optimise desirable qualities including ease of development, robustness and scalability.

Geospatial Digital Rights Management (GeoRM) and provenance:
GeoRM and provenance interface and encoding standards will be critical in addressing issues of security, public access, intellectual property and emergency use of geospatial information. These issues will be important in some VGI applications. The OGC Geospatial Digital Rights Management Reference Model provides the basis for two international standards relating to GeoRM: ISO 19149, Geographic Information – Rights expression language for geographic information and ISO 19153, Geographic Information – Geospatial Digital Rights Management Reference Model.

Points of Interest Data Encoding Specification (POIs): OGC has worked with the World Wide Web Consortium (W3C) to develop an open standard for describing points of interest data. POIs have many uses, including augmented reality browsers, locationbased social networking games, geocaching, mapping, navigation systems and many others.

How open standards are developed
In the past, it has usually been the case that technology providers alone have determined the path of technology's advance, based on their perceptions of market demand. Modern consensus standards organisations like the OGC have evolved to give both technology users and providers a way to cooperatively develop standards infrastructure that guides and supports the advance of technology in ways that are mutually rewarding for the organisations' members. Those who have a stake in the development of standards related to VGI and crowdsourced location data can benefit in participating in the OGC standards activities described above.

Standards organisations like the OGC must remain agile in responding to market changes and trends and they need to stand ready to embrace standards developed elsewhere that have come into wide use or that promise to open up new markets. The OGC has a formal process to help move open but proprietary standards into the OGC's global voluntary consensus standards maintenance process. Google, for example, brought their KML specification into the OGC and Wikitude has brought their Augmented Reality Markup Language specification into the OGC. This approach gives everyone an opportunity to weigh in on the standard and no one individual or entity can unduly influence the standard.