OSM

Having started implementing a Drupal module for OpenStreetMap back in October I have spent a few hours here and there on pushing it forwards. Here's a quick update.

The module is at a stage now where you can download data for a specific region from OpenStreetMap, parse it, filter it by certain tags (and their values, if desired) and then create basic location-enabled Drupal nodes based on the results. Because it ties into the existing location module any other modules which rely on the location API can begin to use these new OpenStreetMap nodes, for example by plotting them on a map, by making the information available through RSS feeds or by displaying them in Google Earth.

I also started working on an OpenLayers module, and at work have been putting effort into improving the MapBuilder module that Nedjo Rogers started a year or so ago. Both of these modules will allow us to reduce dependence in Drupal on commercial mapping providers, instead moving towards using data from other, standards compliant, sources.

Assuming there aren't too many distractions over the coming week or so, I hope to have at least an alpha-quality OpenStreetMap module available soon. Phase one of the module will simply be allowing site admins to keep their local information site up-to-date with geodata from OpenStreetMap. Future phases will almost certainly allow for editing of data and the publishing of that back to the OpenStreetMap project.

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.

I've been thinking for a month or so now about OpenStreetMap and things that I can do to help out the project - besides the data collection and mapping I've been doing since the start of the year.

It all began when I was wondering what the difference in cost would be to an organisation (Futuresonic in this case) between licensing Ordnance Survey data and actually going out and mapping an area themselves.

I wouldn't say the two data sources are directly comparable, but both could meet a given need for an organisation. Often the detail of the OS data would be overkill for orangisations wanting simple maps for context, and potentially very expensive depending on how it's used. OpenStreetMap data, on the other hand, may not have as good coverage - though with time and energy it can be easily extended - but it would be available without the cost.

So, one of the ideas that I've come up with recently is for weekend mapping projects. The basic idea of a weekend mapping project is that I would offer organisations, groups or individuals a weekend of my time to map as much of an area as I could feasibly do in a whole weekend (with extra time afterwards to convert the GPS traces and any annotations such as road names into usable map data).

I think it would be fair to ask for those people to pay for low cost flights from my base to their location, bike rental or something for the actual GPS track collection, and a small amount to cover some cheap accommodation and food for the time I'm there. In return they get free map data onto which they should be able to build, adding their own information and styling to make the maps unique to their own needs.

Why would I offer my limited free time to do this though? Well, quite simply, I really enjoy travelling and seeing new places. I'm also really interested in the idea of open, reusable, community-created content, especially in the form of OpenStreetMap for geographic data, but also Wikipedia for general reference information. So, if I can travel to new places and map them out to help expand the OpenStreetMap dataset, it's hitting on both of those desires in one go.

If anybody is interested, please do get in touch and we can talk through the details.

Updated 15 July with link to page on OSM wiki. Some other community members are interested too, and the more the better as that means sponsors would have a better chance of finding someone close to them, and so have lower travel costs.

Since my initial contributions to the OpenStreetMap project back in January I haven't added much more data to the system. Having no access to a car at the moment, I've not been able to get out and about exploring the area around Stuttgart and take tracklogs as I go. That, and when I was using the OSM site back in January, it had become incredibly slow as the size of the project grew so quickly.

Despite that, a number things have happened recently that have really energised me and encouraged me to get back into the community to create geodata:

• Last week I recieved an email from someone planning on doing a Masters dissertation on the OpenStreetMap project. What's more, he's from the Isle of Man, and doing the same course that I did last year.
• A little while ago, I managed to get another person from the Isle of Man involved in the project. He's now going out with his GPS, cycling around Port St Mary and then adding his tracks to OSM.
• There's a workshop being planned on the Isle of Wight in May at which there's a group of people (who I will join, if I can get there for the weekend) that have a goal of mapping the whole of the island on OpenStreetMap.
• This last weekend, one of the OpenStreetMappers gave me the incentive to classify the data I'm inputting and have already input. He came up with a XSL stylesheet that transforms the raw geodata from the OSM API into an attractive SVG image (sorry to use so many TLAs) that can then be manipulated in other applications. It's the first time I've seen my data visualised in any sort of flexible way, and most importantly the first time it's hit me just how important it is to tag the data (with road names, types, etc) as you put it into the system. Without seeing the effect of your tags, there's no incentive to tag it.
• I tried out the desktop based JOSM editor that lets me edit everything locally and upload any changes - including the ability to tag everything. It's a shame I can only use it on a PC though, so I can only use it after work before going home to my iBook.
• The site itself is now running at an acceptable speed again, so there's not too much delay when adding data.
• Right now there is a very important discussion going on in the mailing lists about the type of license that OpenStreetMap data should be released under, what people should be allowed to do with it, and how they should be able to use it. It's great to read so many people's opinions on the topic, especially as none of the existing open source licences really cater for the needs of open geodata. It also demonstrates just how active and involved the community is.

All of this, along with a bout of nicer weather here in Stuttgart (until yesterday) has made me get my GPS out again and start mapping some of the streets of Stuttgart. I'm thinking small streets that I can walk through and explore instead of roads that, in order to map, I'd need to drive along.