Isle of Man Government
Guess where on the Isle of Man
Since I received the DVD of high resolution aerial imagery and maps from the Isle of Man Government last week, I've spent most of my spare time starting to digitise information for the OpenStreetMap project.
Using QGIS to load in the data, I started to gather all the names from the map that I could, including both place names (for small local areas, hamlets and villages that weren't already in the database) and also farm names. With over a thousand names, this is already a massive boost to the data in OpenStreetMap as it is data that would have been immensely difficult to gather on the ground.
The image to the left represents the shape of the Island, made up of all the points obtained from the map, and soon to be imported into the main database.
The three images below are of small areas that I have started to digitise the buildings of. I'm offering a prize (a pint at the next London mapping party perhaps) to the first person to guess all three places correctly. Two of them may well look familiar to anyone who I chatted to at the 5th birthday party of OpenStreetMap.
Most of the data in the images above (and future data others would like to extract for OpenStreetMap) would have been impossible (well, certainly extremely impractical) to gather were it not for the very generous support of the Isle of Man Survey in giving us a license to derive this information, for which I'm personally very grateful, and I know a lot of other people in the project are also excited about.
These images are licenced as CC-by-SA and the data behind them all will be in the OpenStreetMap database very soon.
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 |
|---|---|---|---|
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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.
Manx Government helps OpenStreetMap
When I wrote my last post about the difference between Google Maps coverage of the Isle of Man and that of OpenStreetMap, I hadn't realised that the OSM version could have been even better without too much more work.
I discovered it only recently, but two weeks prior to my post, Nick Black had posted to his blog about mapping the Isle of Man as well. Nick had been in touch with the Isle of Man's Department of Local Government and the Environment (DLGE, or DoLGE) to see if OpenStreetMap could benefit from any of the mapping data that the government own the rights to. They responded positively to the request and offered a licence to freely derive information from their 1:100,000 map of the Island for use in the OpenStreetMap project.
In doing this, the Isle of Man Government is one of the few cutting edge (a term I wouldn't normally find myself applying to government) organisations leading the way in contributing its data - even if only a subset - to the world of open geodata.
At a scale of 1cm on the map to 1km on the ground, the geodata is only a very simplified version of that collected by the government, yet it can still help tremendously. As Nick pointed out in his post, the Isle of Man did have a fair number of roads covered on OpenStreetMap already, but the coverage was by no means thorough or complete, which is where the new data can help. It helps fill in gaps where roads had not already existed in the database. It helps in the classification of roads between primary (A-roads), secondary (B-roads) and others and helps with assigning the correct reference numbers (e.g., A1) to the roads. The data also helps with the perhaps more difficult to map features such as plantations, peaks, rivers and reservoirs.
Nick has spent some time tracing from the map, as have I, and the open geodata map of the Isle of Man is starting to be beefed up (switch to the Osmarender layer to see the latest map data, though you'll need to zoom in) to include more roads as well as everything else we can derive from the map.
Due to the scale of the government map being used to derive data from, there will be issues in data quality and accuracy, but it is a great start and gives us a broad base set of data to work from, all of which can be improved over time. And it can be improved by anybody who is willing to help. This is still especially important in the towns and villages of the Island where the mapping will still require a lot of work, partly because generalisation on the 1:100,000 map means that many smaller roads are excluded but also because street name data is still something which needs to be collected in other ways - the best of which is by people on the ground who have knowledge of the area.
I wonder if other governments will step forward and offer a helping hand as well?
