Findmypast Tech

Missing Maps

Laura Green Laura Green
Reading time: 2 min

All introductions to Missing Maps include at least a nod to John Snow (the 19thC doctor dealing with cholera, not the GoT hero):

tl;dr: Dr Snow plotted his cholera patients on a map, and when he saw a cluster around a street containing a water pump, he took the handle off the pump and stopped the outbreak. Read the full story about John Snow

That was in 1854. Scale that up to today’s worldwide concerns, where free and up-to-date maps are a critical resource for relief organisations responding to disasters or political crises. The Humanitarian OpenStreetMap Team (aka HOT) along with OpenStreetMap in general, creates and provides those maps.

###Armchair mapping

HOT has an online tool (called the Task Manager) to organise the efforts of “armchair mappers”, providing instructions and little squares of aerial imagery ready to be traced. One evening recent, this is what some Findmypast colleagues used to trace buildings in Swaziland for the Malaria Elimination Initiative to help create a comprehensive building foot print map to aid upcoming field work in 2016.

The Task Manager has several tracing tools available, and the web app one (called iD) is very easy to learn - we were zapping through buildings within minutes of starting. Gratifyingly, our tracing immediately appears in OpenStreetMap - no extra processing required. The HOT Task Manager provides a validation mechanism (by remote mappers, who happen to be passing by) but nevertheless, your own tracing is not in some slow backlog - it’s right there, immediately live and available to use!

There’s also a java app called JOSM, which has a steeper learning curve, but has many advantages to speed things up, and is used by most validators. The more involved in HOT or OSM people are, the more likely they are to get into learning JOSM. iD is perfect for those first steps into armchair mapping though.

###How does tracing get used?

OpenStreetMap provides daily downloads of all areas of the world (this can become hourly, for specific crises). These are used by fieldworkers, using GPS devices, or even smartphones; and NGOs analysing data for all sorts of uses:

Pete Masters, project coordinator, Missing Maps: “Again and again, I hear and see NGOs, such as MSF, using maps that include OSM data in their operational decision making, their logistical planning, their disaster risk reduction programming and their epidemiological analysis. Much of this data has come from Missing Maps and HOT volunteers and a lot of it has come from people at mapping parties.”

In the case of our Swaziland data, it will be used by epidemiologists to track which buildings received indoor spraying, where mosquito nets were received, and occupancy numbers etc. It’s very easy in the developed world to imagine everyone is ‘catalogued’ and ‘numbered’ - but it’s just not the case in the developing world, and this lack makes it very hard and inefficient to provide vulnerable people with the help they need.

###How you can contribute to Missing Maps

  1. Sign up for an account at
  2. Go to and pick a task (read through to see which are easy for beginners) when you first click on a Contribute button, you’ll be asked to allow the Task Manager access to your OpenStreetMap account.
  3. Pick “Edit with iD” and away you go. There’s lots of onscreen help to get you going.

  4. You could sit down with a very large mug of tea and go through the learnOSM docs - alternatively, watch out for the next public Missing Maps Mapathon or join in with the London office mini mapping events (I guess we could also do this remotely??).

###What’s it got to do with Findmypast? We use many open source elements in our products, not the least of which is OpenStreetMap itself, as a “present day” layer (along with two old map layers) on our recently launched 1939 Register. This feature is something our customers like a lot. So we want to do more of it.

There are also many projects within the OpenStreetMap arena that could benefit from our involvement, both from a humanitarian perspective and general technical expertise. After all, we are a clever bunch…

Front End Designer, Findmypast
OSM user: LollyMay