The Open Street Map LinkedGeoData

Open Street Map Linked GeoData (RDF)

Making geographical data more discoverable and accessible:
Open Street Map Linked GeoData

LinkedGeoData is an effort to add a spatial dimension to the Web of Data / Semantic Web. LinkedGeoData uses the information collected by the OpenStreetMap project and makes it available as an RDF knowledge base according to the Linked Data principles. It interlinks this data with other knowledge bases in the Linking Open Data initiative.

The Linked Geo Data Knowledge Base

“In order to employ the Web as a medium for data and information integration, comprehensive datasets and vocabularies are required as they enable the disambiguation and alignment of other data and information. Many real-life information integration and aggregation tasks are impossible without comprehensive background knowledge related to spatial features of the ways, structures and landscapes surrounding us.“

LinkedGeoData uses the comprehensive OpenStreetMap spatial data collection to create a large spatial knowledge base. It currently consists of information about approx. 350 million nodes and 30 million ways and the resulting RDF data comprises approximately 2 billion triples. The data is available according to the Linked Data principles and interlinked with DBpedia.

Accessing the data:

The following interfaces exist for online access:

  • Rest Api: provides basic access to a database with a full Open Street Map (OSM) planet file loaded.
  • Sparql Endpoints: enable queries on databases with a reduced (but hopefully for many applications relevant) subset of the whole data loaded. The Sparql Endpoints come in two flavours:
    • Static: Contains the data extracted from a OSM planet file of a certain date
    • Live: Initially a copy of the static version that is then synchronized with the minutely updates from OSM.


Example Link
http://browser.linkedgeodata.org/?lat=51.063657689874&lon=13.750735172091&zoom=16&prop=amenity&val=

Access to the Data
http://linkedgeodata.org/OnlineAccess

Bing Maps and the Open Map Community Connections

Recap – Automatic Road Detection

Before looking at the new front door application, a bit of history might be helpful about the recent direction that Microsoft’s mapping utilities have been taken. You may be aware that, a few months ago, Microsoft released an application that could be used to automatically detect roads from an aerial imagery photograph. The images below show an example output from the service when processing an imagery tile of part of the city of Norwich:



 


 
One interesting aspect of the service (remember this service is created and hosted by Microsoft, on their azure platform) is that the resulting points were provided in osmchangeformat – and could be used directly to import road data into Open Street Map. This would potentially allow OSM to create and mass import vector road data in previously unmapped areas automatically and easily, without the manual process of a user tracing the road path by hand.

The Front Door Application

The new front door application, which you can access at http://frontdoor.cloudapp.net/follows a similar model of utilising Bing Maps aerial imagery to potentially benefit the open map community…. how?

Anybody who accesses the site is presented with a random aerial image of a location, and is invited to drag a single pushpin onto the front-door of the nearest house. Here’s the image I was presented with when I went to the site just now:

For this one, I’m going to say that the front door of the house is most likely to be just to the left of the driveway, so I dragged the pushpin to about here:

The new location is submitted, and you get shown a new image. What’s the point? Well, if enough people separately agree on the same location for the front door of this house, the new location is used to update local search results in Bing Maps as well as contributing address data to Open Street Maps – crowd-sourced, frontdoor geocoding of properties…

It’s great to see Microsoft continuing to make use of the Open Database Licence and contributing their imagery for use for the benefit of Open Street Maps again (Bing Maps aerial imagery is also available within the PotLatch OSM editor to enable people to trace the location of features and the outlines of building etc.), as well as thinking up innovative uses of the aerial imagery they have available… I wonder what app they might come up with next?

A Google Map Maker Roundup

Google announced today that Map Maker is now available for the United States; the tool that allows users to add contributions to Google Maps had, I thought, been targeted at countries where Google lacked map data, but it appears that user contributions are welcome in countries with existing data — once they’ve been reviewed.

So it looks like a Map Maker vs. OpenStreetMap conflict is shaping up. Last week, Mikel Maron accused Map Maker of copying OpenStreetMap’s model and exploiting freely made contributions in a way that benefits Google, in that the resulting data is not freely available; moreover, he says,

Corporations should not be the stewards of a public resource, and a potentially controversial public resource. Compare Gaza in OpenStreetMap and Gaza in Google for just one example of why this is a bad idea. We’re approaching a situation where a corporation is becoming the decision maker on international borders. Wait, did you think the UN or other international forum was supposed to have some role in these kind of things? Nope, Google is getting UN data too.