Systeme D (geo feed)

Cycle map on your GPS

Sun, 13 Jan 2008 14:04:15 GMT

As often discussed, the National Cycle Network is great fun, but the signposting can leave something to be desired. The Stirling Surveys maps are lovely but only available for a few routes. All of this explains why OpenStreetMap contributors in the UK are mapping the National Cycle Network... but unless you have a particularly l337 phone, you can't take the map with you when you go.

Enter the wondrous Mkgmap, which converts OSM data to .img map files suitable for a Garmin GPS.

By default, the Garmin road styles are fairly car-centric, and the NCN routes aren't highlighted. However, with a bit of preprocessing, I've managed to munge the OSM data so that Mkgmap will make a portable NCN map from it.

(Image thanks to Andy Allan.)

So you have no excuse for getting lost on the NCN ever again. Remind me of that next time I end up on some remote little lane thinking "haven't seen a sign for three miles now...".

World's best mapping still not on the web

Fri, 14 Dec 2007 11:53:28 GMT

The Ordnance Survey yesterday launched a closed alpha of their OpenSpace API, basically bringing Google Maps-like functionality to OS mapping.

Most of the obvious has already been said - great idea, good to see OS opening up a little, looks smart technically (it's using a neatly hacked version of OpenLayers), but maybe too late, and the non-commercial clause sucks big non-commercial rocks. And the little lawyer-infested notes everywhere saying that "JavaScript is a registered trademark of Sun Microsystems" are quite brilliantly "we still don't really get it" naive.

But the biggest disappointment is that you won't see the image above. For the higher zoom levels, OS have chosen to use their utterly anonymous StreetView mapping, which is a not-particularly-great raster set of images exactly like the street mapping on Google Maps. (StreetView is probably actually worse than the Google tiles, because it's clearly derived from a rich dataset with a fairly random set of features left in. So you'll often see the text "Disused railway" in the middle of nowhere, but without the actual line showing where the railway goes.)

This is really dumb. It means the whole project stands or falls on the Landranger (1:50k) mapping, because that's all that differentiates it from being YAmapping API - and Multimap already offer Landranger tiles through their own API.

So what's the alternative? The Explorer rasters (1:25k), as shown above. This provides countryside mapping par excellence, and really shows how they can offer more than the "just streets" approach of TeleAtlas/Navteq etc. Offering the Explorer maps would have Britain's walkers beating a path to your door, and be a nice plus for other countryside-focused sites like Geograph.

(There's precedent for this: OS's largely-forgotten Get-a-Map consumer mapping site does provide the Explorer set, but, of course, no API.)

The API doesn't go public until next year, so hopefully there's time for the Explorer tiles to be added.

Quadrilateral to square

Tue, 04 Dec 2007 00:38:43 GMT

The above images make me happier than any two slightly blurry map scans have any right to.

On the left you can see a map scan and an arbitrary quadrilateral drawn on it. On the right you can see the area from said quadrilateral, neatly resized into a perfect square.

As yet the code is slow (because it's in pure Perl, rather than using Imager's amazing transform2 function), and the results a bit fuzzy (because I really need to do it at high resolution and then scale down). But I'm really chuffed to have got the basic principle working. It's an inverse mapping, i.e. the code loops over every pixel in the square and finds the corresponding pixel�in the quadrilateral (rather than vice versa), so you don't get any holes in the image.

This is the first step in getting the New Popular Edition properly rectified and working as a background layer in Potlatch. There's a lot of effort ahead plotting anchor points for each sheet, followed by some hairy gdal work, but this is the single biggest obstacle overcome. And yes, I will, of course, publish the finished source code.

Five years of GPS mapping

Wed, 07 Nov 2007 12:23:32 GMT

Here's an anniversary I should have blogged earlier this year.

In August 2002, Ben Jameson, Andrew Bolt, Matthew Slattery, Robert Brown and I, sitting in the bar of a Caledonian MacBrayne ferry from Colonsay to Oban, hatched a plan for a user-editable website with maps made from GPS tracks.

In September, I bought a Garmin eTrex in Keswick, a serial cable from eBay, and a USB adapter from a computer dealer in South Wales; recorded my first GPS tracks; downloaded them; converted them into an Illustrator file; and started on the map. I've still got the tracks:

In mid-September, I wrote some HTML for a website mockup:

(I wish I could remember what the 'Destroy' option was meant to do.)

By early November - five years ago as I write this - I'd made this map using GPS tracks, Illustrator, and scans from an out-of-copyright map:

and using similar methods, was working on one of London:

There were some collaborative features in there that look ordinary now, but were pretty cool back then:

(Looking back on my notes, I'm amused to read: "Enter a licence URL, or leave blank for no restrictions. We suggest you think carefully before choosing a licence, such as the GPL, which restricts further use of your file.". Plus ca change...)

Early in 2003 I imported roads, coastline, and built-up areas from the Digital Chart of the World, or VMAP0, which I'd downloaded at work and brought home. Coupled with roads from an increasing number of GPX tracks, it was starting to look like a real mapping website.

geowiki.com sneaked onto the web that spring with nary a fanfare. And, of course, Geowiki itself never became front-page news, but free GPS mapping certainly did. Thousands of people are now uploading tracks to the web - my personal tally is well over 20,000 miles now - and making a big, big map out of them; and a small core of very, very talented enthusiasts are producing the genius code, renderings, events, and community that drive it all.

We all take a while to settle into the roles that best suit us. Five years on I'm pretty happy with my role as a cog in the open mapping machine and OpenStreetMap in particular. I get to do a lot of cartography and UI-led application design. I get to learn cool stuff - ActionScript, for example, and how to do stuff with SRTM. (It still makes me giggle to think that Geowiki is entirely flat files because I didn't actually know what SQL was.) And I have a lot of fun throwing ideas out there, especially when some of them stick - like, "let's map the National Cycle Network". Yet there's never so much that I can't do all the other things I enjoy: if Geowiki as a site was to get anywhere then there'd have been a lot less of the fun stuff, and a lot more of the sort of bullshit that ended up exasperating me so much at Waterscape.

And the best bit? I have absolutely no idea what will happen in the next five years. Maybe it's time to do something new with the Geowiki domains?

Blowing away the dust

Mon, 17 Sep 2007 17:24:49 GMT

I haven't got a Daring Fireball-type long post to hand, nor a witty one-line apercu (as if I ever do), but given that it's almost two months since I last posted something here I figured a few sentences might be in order.

We've been cycling. Quite a bit: a week around Brittany, a weekend (just gone) around Somerset, and the usual pootles around Oxfordshire. And we did get wet in Brittany, but not quite as wet as we did here in Charlbury. On the days the heavens opened, I was driving to James Needham's wedding. In Ledbury. How do you get from Charlbury to Ledbury? Well, Tewkesbury, Moreton, Cheltenham, Gloucester, they're all good places to drive through. Usually, that is.

I heartily recommend the Philips Navigator and AA Close-Up Britain atlases for such occasions, because they show even the most minor of streams, so you can plan your route to cross as far upstream as possible and thereby avoid your Pluriel being swept away in a raging torrent.

The AA Close-Up Britain atlas is wonderful in another way: it shows the National Cycle Network. This is kind of useful given how slow the Sustrans map site is. Of course, in the true tradition of building-a-better-mousetrap, we can actually do something about the latter, i.e. prepare an OpenStreetMap replacement. Andy Allan has produced this excellent Mapnik-powered National Cycle Network map from OSM data, and Anna and I are having great fun - as, it seems, are many others - taking every opportunity to gather new data for it. How can you not love a route that takes you past Glastonbury Tor on a little windy lane (pictured)? (The bed and breakfast we stayed in was using Eviivo Frontdesk. I laughed.)

Potlatch, my OSM Flash editor, has come on quite a lot recently. It now almost does everything in my surveying workflow: imports and simplifies GPS tracklogs, copes with points of interest, and so on. The one major thing missing is support for OSGB, so I can trace over the New Popular Edition.

Tea Cottage - Mum's lovely Rutland house - is for sale. Anyone looking for a beautiful house for sale in Rutland, especially search-engine spiders, could do a lot worse than look there.

We went for a week around the Warwickshire Ring on Iago, aided by Ben and Louise, and I'm not going to spend half a day blogging that because you can read it all in the current Waterways World instead. And I still haven't finished the WW website, but I'm getting there.

Mah fellow mappers

Thu, 19 Jul 2007 22:11:51 GMT

OpenStreetMap's first conference, State of the Map, was last weekend. Some highlights:

Luka Frelih's magic surveying bike, with a special dial that let you survey the Eiffel Tower in just one click. At least I think that's what it did
Ivan Sanchez Ortega relating how he's almost persuaded the Spanish equivalent of the Ordnance Survey to give us all their data. Holy cow
Google's EMEA Chief Geospatial Bloke and the founder of Multimap sitting on the floor listening to whatever madcap scheme was being expounded
Mike Calder's plan to vectorise the entire New Popular Edition, which easily out-madcapped anything else
Not dying on my feet during my presentation, or indeed the licence debate, which I was more nervous about
Etienne's stats appearing to show that OSM usage is doubling every five seconds, or something
About eight people coming up to me and saying: "I use JOSM, but my dad/brother/boss/dog uses Potlatch and loves it". Yay! That's the idea!
About eight zillion Potlatch bug reports and feature requests (of which I've just ticked off the first one... only 7.999999 zillion to go)
The general tenor of the conference: pretty much everything was interesting; and pretty much everyone was interested - the lecture theatre was packed most of the time
Namecheck for Geowiki in Steve's keynote. Aw, shucks
Looking at the shiny map of UK coverage on the wall and realising it's already out of date
Licence debate not ending in a fist-fight
Barry Crabtree's presentation aka OpenStreetMap On Crack

And here we all - well, mostly - are.

Reborn slippy

Fri, 15 Jun 2007 14:18:55 GMT

When even Streetmap.co.uk has implemented a slippy map, you know that it's time to look for the next big thing.

I am not at Where 2.0

Thu, 31 May 2007 11:19:21 GMT

But, were it not for the trifling matter of a magazine deadline, organ-playing appointments, etc. etc., I would quite like to be. Come to mention it, Anna has expressed an interest too. I don't think it's so much that she wants to find out the latest in the geohacking sphere, more that she'd like a holiday in San Francisco.

However, I will be at State of the Map, Britain's - and, in particular, OpenStreetMap's - answer to Where 2.0. To be held in Manchester on July 14th/15th, it has a pretty impressive panel of luminaries for an inaugural event: Ed Parsons (Google, ex-Ordnance Survey), Sean Phelan (Multimap), Steve Chilton (chair, Society of Cartographers), and, of course, leading lights from the hacking contingent such as Steve Coast, Mikel Maron and Andrew Turner.

And I'm giving a talk, too: Why Mash-Ups Suck (and Cartography Matters). It's not a talk on how to do cartography, but rather, why to do it.

After all, who's really spending time on cartography right now? Google, for example, seems to be trying its utmost to supplant cartography with reduced reality - whether through its new StreetView photos or Google Earth's physical modelling. And that's a shame, partly because an illustration can often convey information that a photograph doesn't, partly because good cartography is good art.

Meanwhile, third parties - all these zillions of mash-ups - are simply adding pushpins and squiggly lines to the same old road atlas and streetmap base tiles. True, these pushpins and squiggly lines are sometimes in really significant places, but you'd barely believe it from the presentation.

So come and listen to me rant, and to a further series of marvellously titled talks: 'OSM and the Art of Bicycle Maintenance', 'The Cathedral and the GPS', 'Map Room 101', and my favourite title, 'This Mapping Stuff Could Really Take Off'. Register here.

(Being the first in a series of three long overdue mapping-related blog posts.)

Playing with Potlatch

Thu, 08 Mar 2007 12:35:32 GMT

On the OpenStreetMap dev server here; mailing list posting here; wiki and bug reporting here.

Streetmap updates its imagery

Wed, 14 Feb 2007 14:15:58 GMT

...and says bye-bye to the Ordnance Survey?

The public site still looks the same as it has done since 1802, but their version for Rightmove has been updated at street level - look here, for example. The labels are now Helvetica (or similar) rather than the unreadable Avant Garde-ish font they used to have, and interestingly, the credit in the bottom left is now to Navteq rather than Ordnance Survey.

The Landranger (OS 1:50k) and Bartholomews road atlas layers appear to be unchanged, so there's still no sign of the Aston Clinton bypass on the 1:50k, for example.

Interesting to see, once again, a major webmap company trying out new things on their embedded sites before launching them publicly. Similarly, Multimap's mapping for Yell has been AJAX 'slippy' for a while now, but multimap.com is still one page per map view. (It's worth pointing out that OS's licence terms and conditions pretty much require this, unless they've changed significantly since I was at Waterscape.)