Linked Data is the concept of representing information on the internet through a unique URI. I touched briefly on linked data a few months ago with respect to making data open, but thought recent developments in the field of geospatial linked data made this topic deserving a full post.
Linked GeoData is a project from the University of Leipzig which exposes OpenStreetMap in Resource Description Framework (RDF). RDF is an XML-based way to represent data, as well as data which is related (linked) to that data. This presents an interesting opportunity for people using linked data in their applications to add spatial components. For example, you can get all points of interest in OSM within 100 meters of any point with http://linkedgeodata.org/triplify/near/[latitude],[longitude]/100. The data comes back in standardized RDF xml which can easily be parsed to get information about what is around that point.
It is interesting to see the linked data concept be applied to spatial linkages between objects, which can be combined with other linked data sets to add a spatial dimension to other linked data sets. For example, the Friend of a Friend (FOAF) Project aims to link data “…about people and their activities (eg. photos, calendars, weblogs), to transfer information between Web sites, and to automatically extend, merge and re-use it online.” FOAF often has coordinates representing a person’s location, usually a simple latitude and longitude for their home or office. These coordinates can be used to geographically link people to anything in OpenStreetMap, as a supplement to existing friend relationships.
This is a fascinating field that is certainly something to keep an eye on in the near future, as more linked data sets become available extending the links even further. Hopefully Linked GeoData is just the beginning of the geospatial community embracing linked data.