Introducing Portable OpenStreetMap
For the past several months we’ve been working with SpatialDev and the American Red Cross on a project we’ve been calling Portable OpenStreetMap (POSM).
The initial goal was to integrate Field Papers and OpenMapKit to support the workflow used by Missing Maps efforts around the world, which aim to help some of the world’s most vulnerable communities by putting them “on the map” for the first time.
However, it quickly grew beyond that, as we realized the possibilities opened up by bringing more of the “humanitarian stack” together in the service of truly open mapping: HOT’s OSM Export Tool, the Overpass API, JOSM, the OSM website, Field Papers, OpenMapKit, and others.
Field Papers and OpenMapKit typically require mappers to return to a network-rich environment after spending a day in the field in order to synchronize, digitize, and submit edits to OSM. However, in many of these locations, there is no reliable network or basecamp with which to sync. The need to have an offline workflow becomes critically important.
POSM extends this functionality by enabling volunteers to bring OSM data into the field on very small servers that host their own wireless local area network, allowing editing to occur without any access to the Internet at all. POSM devices are small form-factor PCs running Linux, built from components that can be purchased for about $300. They are sufficiently lean enough to be powered by commonly available sources, such as motorcycle batteries.
In addition to adapting and gluing together components from the humanitarian stack to work better offline, we also designed some custom cartography (POSM-carto) to highlight OSM Humanitarian Data Model features and to include edits made in the field. We also developed a process for merging offline OSM edits back into OpenStreetMap.org that we refer to as the POSM Replay Tool (more on that later; it’s a crazy problem where having the stage set helps).
Nicholas Hallahan, OpenMapKit’s lead developer, and I had the opportunity to join American Red Cross GIS staff and the Cruz Roja Ecuatoriana in Huaquillas, Ecuador for a field test in March. Over a couple weeks, we helped train Ecuadorian volunteers in the Missing Maps methodology. When we weren’t out in the field, we stayed behind in air conditioning and found ways to make POSM work better with large groups of volunteers in network-poor environments (in this case, hotel wifi).
We’re excited about the possibilities inherent in being able to bring data with you wherever you go, however remote, and look forward to seeing how other NGOs and for-profits can benefit from this approach to improving OpenStreetMap.
If you’re at State of the Map US in Seattle in July, look for Missing Maps talks, find me (Seth) to learn more, and join the Birds of a Feather session we’re planning on holding. I’ll also be at the code sprint on Monday with some POSM devices to try out.
