mapping
Google Maps vs OpenStreetMap
Some of the cartographers on the OpenStreetMap project (which includes the chair of the Society of Cartographers in the UK) got together a few weekends ago for a cartography discussion day to try and clean up the rendering of free geodata from the project. The results of that day are now starting to appear on the maps, with much of the extraneous detail being stripped until you zoom further in, revealing more on each zoom level so as not to clutter the smaller scale maps.
With the changing of the maps I wanted to see how the Isle of Man was looking. I have to say, it's looking even better than the previous big update to mapping.
When I first learned about OpenStreetMap at the Open Geodata Forum I wasn't entirely convinced it would take off, though I was intrigued by the concept. Almost two years down the line and my opinions have definitely changed on that, as have the opinions of many others, including people in the geographic information industry.
To see why my opinions have changed, just compare the open street map of the Isle of Man to the Google Maps version which shows nothing except its name and an outline of the Island (with the Calf of Man joined at the bottom as if a bridge had been built to the islet).
With open geodata anyone can just go in and add new information or alter existing information if there are errors in it (like the link between the Calf and the mainland, for example) but you can't do that on Google Maps. Admittedly the Manx map is still somewhat lacking in certain areas, but it's a work in progress and it's getting there, slowly.
2 ©2007 individual contributors, licensed under Creative Commons Attribution-ShareAlike 2.0 license
Free maps get a great new look
The free-to-use maps that volunteers in the OpenStreetMap project have been building over the past year or two have been given a new look. Thanks to the Mapnik project, the new maps look much more like Google Maps et al. and are actually available through the 'slippy map' interface on the OpenStreetMap website instead of having to download the data and generate them locally as had been true until recently (e.g. see the map of Stuttgart I generated recently).
There are a lot of tiles to generate, and it may take some time to generate tiles for the whole world. The focus therefore had initially been on getting England covered, but is now expanding to cover other areas. Nick Black stepped in to render the Isle of Man, where these examples are from.
Free map of Castletown, Isle of Man
Free map of Port Erin and Port St Mary, Isle of Man
These maps are all available under the Creative Commons Attribution-ShareAlike 2.0 license.
Old maps of the Isle of Man
A couple of weeks ago I started looking around on eBay for old maps of the Isle of Man, partly because they may be of some use to the OpenStreetMap project, and partly because it would be really interesting to see what had changed in the past fifty or hundred years around the Island.
The thing that triggered me to go out and find them was the launch of Richard Fairhurst's online browser of the 1930s and 40s Ordnance Survey New Public Edition map of England and Wales. He'd spent quite some time collecting the maps from secondhand shops knowing that 50 years after their publication the copyright on them expired and hence they get released into the Public Domain where anybody can do with the data what they wish. He worked with a couple of other people to scan all of the maps and build a site that lets people browse them and start to build up a copyright-free database of postcodes. It lowers the barriers for people willing to share the locations of their postcodes, and makes it much easier (though less accurate) than the Free The Postcode method of getting people with GPS units to submit precise coordinates for postcodes they know.
But back to the maps of the Island. The one map I was most interested in was the Second War Revision (Sheet 17) published by the Ordnance Survey in 1940. It covers the Isle of Man at a similar scale as the modern Sheet 95 of the Landranger series, but is now in the public domain, having been published 66 years ago under Crown Copyright. It will be a great reference point for extracting data for OpenStreetMap, showing the paths of rivers and roads between towns and villages on the Island. It doesn't really give enough detail to be useful within the towns themselves.
I also found some old street plans of Douglas, Onchan, Ramsey, Port Erin, Port St Mary and Castletown dating back to the late 40s (the Peel plan appears to state Nov 47). They can't be used for anything other than personal interest, as far as I'm aware, because they weren't published under Crown Copyright and the copyright instead falls either under the local authorities of those places, with the cartographers, or with the publisher. All of which mean that the maps won't fall out of copyright until at least 70 years after they were published, or 2017. Or at least, that's as I understand it.
The 1963 Ordnance Survey map (Sheet 87) I also found would have fallen out of copyright a little before that, in 2013, but in reality it probably doesn't give much more information than the 1940 version, and the Island will have long been mapped in OpenStreetMap by that point.
Talking of mapping the Isle of Man, I am planning to do some more mapping of Castletown and Douglas for OpenStreetMap between Christmas and New Year. If anybody is interested in helping out or finding out more, just get in touch. I have a spare GPS unit that can be used as well.
Mapping Stuttgart on OpenStreetMap
Since the Munich mapping weekend a few weeks ago I've been putting some more work in to try and improve the mapping of the centre of Stuttgart in OpenStreetMap.
The image above shows the current state of the map for Stuttgart. It's still missing a lot of information including many of the major roads, mostly because I don't drive here. There were also very few streets in the centre of town until this weekend when I made a conscious effort to go in and collect data for some of the pedestrian areas of the city.
If you're in Stuttgart and interested in helping out with mapping, get in touch. There is GPS data appearing in the area from someone driving around, which acts as a good base for some of the major roads, so if that's you, get in touch and maybe we can work together to make sure they're tagged with street names and the like.
Mapping Munich in a weekend
Early on Saturday morning I got up to catch a train to Munich so I could meet up with a small group of other OpenStreetMap people with the aim of mapping the centre of Munich in a weekend.
I'm not a big fan of mornings but still I managed to get up early enough that I'd arrive into Munich not too long after the others had met. I arrived there, a little bleary eyed from snoozing on the train, and headed to Marien Platz to meet Ralf - the organiser - to find out which part of the city I should go off to map.
I went off to map inside the north western corner of Munich's Inner Ring road with a newcomer to the project. Mapping an inner city area, as I discovered when starting to map Stuttgart, is not an easy task. The GPS units stuggle because of the tall buildings and often narrow streets. It's difficult for them to keep a lock on the satellites, and when they do there is often still interference from all the buildings around that leads to tracks not being anywhere near as accurate as desired.
After a few hours of mapping it was time for lunch and time to meet the others. There were a group of eight of us, each paired up to take a part of the city centre. I struggled through lunch trying to understand as much of the German language conversation as I could, not really able to add much because my German's not good enough to butt into conversations with yet. After a pizza and a beer, it was time to go back to our areas and finish up the mapping.
By the time we all met again in late afternoon we were all starting to feel a little sore under foot, so happily sat down to see how we had all progressed on the first day. There was a slight worry at one point, after downloading the tracks from one type of GPS unit (the NaviGPS, which most of the group had) appeared to have no data from the morning. It turned out later on that evening that the data hadn't been lost, but for some reason there were some issues with the SD cards that the GPS units save the tracklogs onto, meaning that not all the files were showing.
By the morning, Joerg had printed out some updated maps to work from, as we'd all agreed that it was much easier to fill streets in on a skeleton map than to try and start from scratch. Some of the areas hadn't been mapped as a few of us didn't have the ability to go in and draw street segments on top of the GPS tracks, but Joerg and Ralf had both managed to do at least some amount of mapping the streets online in OpenStreetMap from the previous day.
There were four of us on Sunday, two on bike and two of us not. The two of us not on bikes headed down towards Museumsinsel - the location of the Deutsches Museum - to map that area before meeting for lunch. After lunch came another couple of hours of mapping an area around Ost Bahnhof.
After all of that walking, we still need to go in and create all this data in the OSM wiki based on our GPS tracks, notes, diagrams and memory. That's what I've been doing tonight, and still there are a lot of names I have to fill in from the map we drew. Already though, the central area of Munich is looking much more densely covered with map data than before the weekend.
