Using official Isle of Man map data in OpenStreetMap

Before traveling back to the Isle of Man for the second Manx mapping party, I received an email from Juan Watterson, the Member of the House of Keys (MHK) responsible for the Isle of Man Government's mapping efforts (as part of the Department of Local Government and the Environment) who was interested in OpenStreetMap and in particular the Isle of Man mapping project. Juan kindly put me in touch with the Government's Senior Cartographer, Rob Clynes, with whom I met up when I was on the Island.

Back in 2007, Rob offered Nick Black the use of the official 1:100,000 small scale map of the Isle of Man from which to gather data for OpenStreetMap. Since then, CloudMade mapped the Island more thoroughly than we had done previously, and donated their data. While that gave a massive boost to the map data for the Island, there was still plenty more information which could be added to the map, hence the recent mapping party.

Meeting with Rob, he talked me through me some of the work he does, like digitising high resolution aerial imagery, change monitoring, co-ordinating the updates of the imagery, and cartography for the smaller scale maps (1:100,000 and 1:25,000) they produce - largely as a side product - and turn into printed maps. It was interesting to compare the data collection and management processes they have with those we use in the OpenStreetMap project, comparing my Walking Paper scrawls and GPS tracks from the weekend before with the official map data creation.

Having chatted with Rob for a while, he mentioned that he should be able to sort out some more data to help out the OpenStreetMap project. I got home yesterday to find a DVD of geodata sitting on my door mat. We now have access to two datasets from which we can derive data for the project:

  • the 1:25,000 tourist map (2007), provided as a set of four GeoTIFF images
  • the high resolution aerial imagery (2001), provided as a set of three MrSID images
OpenStreetMap IOM Government 1:25,000 IOM Government aerial imagery using overlays
Crosby, Isle of Man - OpenStreetMap Crosby, Isle of Man - 1:25,000 Isle of Man Government map (2007) Crosby, Isle of Man - Isle of Man Government aerial imagery (2001) Crosby, Isle of Man - OpenStreetMap, Isle of Man Government aerial imagery (2001) and 1:25,000 map (2007)

There is a massive amount of information which we can gain from these datasets still, and I will be posting some ideas soon about different possibilities, such as collecting place names, paths and tracks, historic sites, outlines of the national glens, open rambling land, etc. as well as using the data for error checking and correction in the existing OpenStreetMap dataset.

I am planning to make these datasets available as a WMS server that can be used in JOSM (and Potlatch) for editing, once I've had a chance to organise it, and have had an official license document through.

If you're interested in helping collect data from the data to add to OpenStreetMap, please leave a comment below or get in touch.

* Isle of Man Government map data and aerial imagery © Crown Copyright, DLGE; OpenStreetMap data © OpenStreetMap and contributors, CC-by-SA.