One of the more interesting things to happen for me as a result of the air traffic turmoil caused by the volcanic ash clouds from Eyjafjallajökull - other than fretting about my chances of getting to Europe as planned at the start of May (I'm now cautiously optimistic, though hardly because of Qantas's handling of the situation) - was that I discovered the Flightradar24 site, through a link on my colleague Jo Jacobs's blog. What a powerful demonstration of the power of crowdsourced geodata mashups!
If you haven't seen this site yet - go there! It's the kind of user-generated information resource which only a few years ago we couldn't even have dreamt of, but which now relies on no more than the willingness of a few dozen users world-wide to invest a reasonably modest sum in hardware, and of a few hundred more (I'm guessing) to contribute their time to develop the system and curate the data it relies on.
Flightradar24 aims to track - mainly commercial - aircraft, live, as they fly their various routes around the world, and while its coverage to date is mainly focussed on Europe (with a few contributions from the Americas, South Asia, and Australia), for that continent it does exceptionally well. There's no unauthorised use of data involved here - in the first place, the site simply relies on commercially available devices that receive the transponder information (flight number, aircraft type, height, speed, position, etc.) which is constantly transmitted by commercial airliners - and a few others, such as the planes of the Australian Royal Flying Doctors Service.
And like any good geo-mashup, it maps that information onto a Google Maps map - but from here, it also plugs into a set of other databases which track the longer-term historical information, such as the routes previously flown by a specific plane, the particular planes used to service a specific route, or the current departures and arrivals at a given airport. Where available, it even offers photos, not of the generic aeroplane model, but of the particular plane itself, provided by your friendly neighbourhood planespotter. (Find more information here.)
Where this got really interesting was during the major airspace shutdown as the volcanic ash cloud made its way across Europe, of course - as a map usually filled with nearly 1000 planes at any one time suddenly cleared almost completely. Indeed, for all the frantic reporting of airport shutdowns and travel delays over the past week or so, few images better summarise the impact of the event than Flightradar24's map of the most affected area, tracking just a single lonely KLM test flight. (The colours in its trail indicate the plane's altitude as it climbed through different flight levels to test conditions.) The site also tracked the first flight to land at Heathrow after it reopened, and has a few other interesting screenshots.
What this puts into its users' hands, especially during emergency situations such as this, are the tools to see with much greater transparency than would otherwise have been the case how things are really playing out on the ground (or rather, in the skies). So the media report that airlines are flying again? Let's check for ourselves. An aircraft involved in an incident is reported to have been serviced just recently? Let's find out whether there have been any maintenance breaks in its recent service, or whether it's been doing the Sydney-London route day after day over the past month. (Perhaps you can think of a few more such scenarios.)
And all this just because a bunch of people around the world forked out the cash to buy €500 receivers - that comparatively modest investment, plus some time spent developing the system which handles the data, has resulted in a crowdsourced, user-generated, bottom-up, and potentially global flight tracking system. Not a bad job at all...
And just a couple of days after I posted this, I came across a visualisation of the European airspace shutdown (and its gradual reopening), using Flightradar24 data. Brilliant (h/t to @wolfcat).