geobloggers: “Network Link” in Google Earth

This is the hidden gem of Google Earth. Adding a “Network Link” allows you to fetch KML data from remote servers. It does this in two ways, Time Based or Location Based. So *anyone* can add dynamic data to Google Maps.

Apparently KML is based on GML. I don’t know Keyhole/Google’s work differs. There seems to be a role here for something simple enough for Google Earth, WorldWind, and other viewer apps to use, when consulting a remote server for info about some area of interest. Maybe it’s GML Web Feature Servers, maybe KML, maybe geo-extended RSS/Atom, or perhaps generic query interfaces like the SPARQL protocol. SOAP, WSDL and REST fit in the picture somewhere. Probably, various things will be used in different environments, depending on application emphasis. We might be looking up the opening-hours of a shop, contact information for an organization, or jobs, events, photos, blog posts, FOAF profiles etc in a certain area, … it isn’t clear where the line is drawn between ‘geographic’ data and the wider unbounded collection of information about the world. GML has strengths at the geographical end of the spectrum, RDF (and its query system, SPARQL) has strengths at the generic, domain-neutral end. RSS/Atom is serving well as a generic carrier for data syndication. It isn’t clear to me yet where KML fits (or SVG, for that matter), but work on the relationship between GML and RDF would seem timely.

The geobloggers post has examples and links to flickr and del.icio.us-based services that expose this interface. I’m going to try making such a service on top of SPARQL…

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