Last week hundreds of delegates from government, civil society and business gathered in Brasilia for the first Open Government Partnership meetings since the inception of this initiative. Transparency, accountability and open data as fundamental building blocks of a new, open form of government were the main issues debated.
Fabricio and Alex getting ready to survey the Cruzeiro neighborhood in Brasilia.
OpenStreetMap, sometimes dubbed the "Wikipedia of maps" is an open geospatial database. Go to openstreetmap.org, create an account, and you're ready to edit the world. The accessibility of this form of contribution paired with the openness of its common data repository holds a powerful promise of commoditized geographic data. As this data repository evolves together with a surrounding tool chain many more players gain access to geospatial analysis and geo publishing previously limited to a few; at the same time highly expensive geo data sourcing is placed into the hands of the many.
When Steve Coast founded OpenStreetMap in 2004 {fact check} the proposition to go out and crowd source a map of the world must have sounded ludicrous to most. After [pivotal growth in 2008](ito video) and the widely publicized rallying around mapping Haiti in 2010 the OpenStreetMap community has proven how incredibly powerful a free floating network of contributors can be. There are over 500,000 OpenStreetMap contributors today. About three percent (that's still a wopping 15,000) contribute a majority of the data. About 1,300 to 1,400 contributors join each week. Around the time when Foursquare switched to OpenStreetMap and it turned out that Apple is using OpenStreetMap data in iPhoto we saw this number jump to even 2,300.
For the OpenGovernment Partnership Meetings we wanted to make contributing to OpenStreetMap very concrete and two days before the meetings kicked off, we invited early arrivers to join us for a mapping party. All we did? Drive and walk around neighborhoods surveying street names and points of interest. This is just one technique of contributing to OpenStreetMap, something that is actually quite simple and fun. Let me give you here a run down of the most common ways of adding data to OpenStreetMap.
It takes 2 minutes to lay the groundwork for being an OpenStreetMap contributor: create a user account on openstreetmap.org. Once that's done, you can immediately zoom to your neighborhood, hit the edit button and get to work. This is fine for quick tasks, but the nicer editor to use in most cases is JOSM - downloading and installing it is just another 5 minutes, and I recommend you do so.
Once you start JOSM you can download an area of OpenStreetMap data, edit it and then upload it. Whatever you do, it's crucial to add a descriptive commit message when uploading - this is very helpful for other contributors to out figure intentions and context of an edit. Common first edits are adding street names to unnamed roads, fixing typos and adding points of interest, for instance a hospital or a gas station. Keep in mind that any information you add to OpenStreetMap must be observed facts or taken from data in the public domain, so for instance copying street names from Google is a big no-go.
JOSM allows for quick tracing of satellite images, you simply turn on a satellite layer and start drawing the outlines of features that can be found there: streets, building foot prints, rivers, forests. Using satellite imagery is a great way to create coverage fast, we have written up an entire blog post with more detailed instructions on it. Here is an image showing the progress in tracing Brasilia in preparation for the OGP meetings:
OpenStreetMap contributions in Brasilia between April 5th and April 12th.
Progress in Brasilia between April 1st and April 15th
In places where you can't find good satellite imagery, a GPS tracker is your friend. OpenStreetMap offers a good comparison of GPS units. Whichever device you use, the basic usage is the same: you track an area by driving or walking it off and later load the data into JOSM where you can clean it up, classify it and upload it into OpenStreetMap.
Synchronizing your camera with the GPS unit.
For our survey in Brasilia, we used walking papers. Walking papers are simple print outs of OpenStreetMap allowing for written notes on paper. This is a great tool for on-the-ground surveys to gather street names and points of interest. It's as simple as you'd imagine: walk or drive around a neighborhood and write up information you see missing in OpenStreetMap. We have written up a more detailed report from Brasilia on our blog.
Walking papers for Brasilia
Ready to get started and full of questions on the details? Take a look at Learn OSM - this is a great resource with step by step guides for the most common OpenStreetMap tasks or just tweet at us at @mapbox.