mapping
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.
Help map the Isle of Man
In just two weeks time, on Saturday 1st August 2009, I am going to be organising a mapping party in Douglas, Isle of Man for the OpenStreetMap project. The aim of the project is to build up a map of the world that can be used without the restrictions that are typically imposed by mapping providers such as Google Maps.
The Isle of Man already has a great amount of map data in the database - as you can see on the map at openstreetmap.org - so we have a good starting point, but it isn't yet complete, so there is plenty of information that we can still add. While the road network is very close to complete, we are missing many of the points of interest you might like to see on a map, or be able to search for (perhaps through a website, or in the future from your in-car navigation device), like pubs, cafes, restaurants, libraries, hotels, historic sites or museums, for example.
We also have some Manx names for places and streets, but this isn't yet widespread, so it would be great to capture this information from street signs around the town.
As we have a good street network already, the need for a GPS isn't as important as it was earlier on in the project, so the plan for the mapping party is to use printed maps (from the excellent Walking Papers project) onto which we can add annotations during the day. At the end of the day, we can use the paper maps for reference when entering the information into the map through the OpenStreetMap website, or scan them in and deal with them later, depending on how tired people are after a day's mapping.
If you're on the Isle of Man and interested in making or using maps (or just the underlying map data), then do come along and find out more. If you're also interested in a little exercise, come out with us and explore Douglas for the day, collecting information to add to the map. You can find out more on the OpenStreetMap wiki, or alternatively contact me if you'd like more information.
If you run an organisation on the Isle of Man which uses geographic information (e.g. business listings) and would like to find out more about including your information in the map database so they can be displayed on the map, or would like to use the maps on your website with your own information displayed on top, please get in touch.
(map from OpenStreetMap, CC-by-SA)
Brush up your cartography skills
In September, the Society of Cartographers is going to be holding their 45th annual Summer School event in Southampton.
It's interesting looking through the programme to see just how much of the event is about data, and much of it coming from sources that didn't exist just a few years ago, from OpenStreetMap, the new UKMap and of course the various Ordnance Survey datasets that are available to organisations who can afford to pay for them.
I wonder how the content of this annual summer school has changed over the years since it started, as more and more data sources have become available for cartographers to use?
If you're in the UK and are interested in making maps, the event (7-9 September) looks like it will be a good place to see where cartography is heading, get some hands on experience in the workshops and also network with others in the industry.
Making maps from OpenStreetMap geodata
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I spent some time last year making some maps of the Snaefell Mountain Course (and other roads) on the Isle of Man so that I could add an overview map to the Wikipedia entry for the course.
Last night I was trying out some of the options in the OpenStreetMap 'export' tab, and since it can now export SVG (scalable vector graphics) files, I thought I'd have a try at redoing the maps from last year in a more re-usable and editable form using vector graphics instead of bitmaps.
To make the SVG map using data from OpenStreetMap (as shown in the preview), I just followed some relatively simple steps and a little trial and error while using the graphics editor.
I thought I'd share some of the steps below, in case anybody else was interested in making maps from the great data becoming available in the OpenStreetMap project.
So, what's needed to make your own custom maps?
- An area of OpenStreetMap that's got enough information in it to be useful for your purpose.
If the data you want is not all there, or you want to add more, see the beginners' guide and the map making guide to get you started off adding or improving data in the project. - An SVG image generated from OpenStreetMap using the export tab.
To export your vector graphic file, zoom the main map into the area you want to export, click on the export tab, tweak the area you're interested in (if necessary), select 'Mapnik image' and 'SVG' from the options and click Export. Experiment with the scale to see what the results are, but initially the default scale will probably suffice. - A vector graphics editor such as Adobe Illustrator or, even better, an open source editor such as Inkscape.
Open the downloaded SVG file in your editor and you should see a nice pretty OpenStreetMap image there. To start to work on it, it's a good idea to 'ungroup' the items so that you can edit them individually (I had to do this twice to fully separate out all the objects). You'll notice that the map is made up of many objects, one for each node and way you'd normally see rendered on the maps at openstreetmap.org. You'll also notice that text annotations (names, road references, etc.) are all broken down to their constituent characters too. - Some time to do some (at times quite fiddly) image editing and map making.
You can get some results out in a relatively short timeframe, but you'll likely want to improve the map over time as you become more familiar with the data and tools available.
What steps were needed to create the TT map?
- Select all the items and fade them (I lowered the level of transparency, but there are probably better ways of doing it).
- Select the text items, group each the characters of each name together to make it easier to edit them, re-emphasise them, and change their size if desired.
- Select any other items that should be re-emphasised and do that (I did the sea and the land).
- Select each element of the subject that you'd like to highlight (for me, this was each way that makes up the course) and change the styling of it (I increased the size, and re-emphasised the original colours). I also combined them all into a single 'path' and joined the end of each one to the end of the next (using the 'Edit paths by nodes' ad 'Join selected end nodes' tools) to make it fill in the gaps that appear between them.
Hopefully this short tutorial (well, documentation of my first steps) was helpful for other budding neo-cartographers out there. If you've made your own maps from OpenStreetMap data and have any hints and tips that may be useful, please feel free to add a comment to this post.
