How Flight Tracking Works: a Global Network of Volunteers

An anonymous reader writes If a website can show the flight path and all those little yellow planes in real time, how can they not know where Malaysia Airlines flight MH370 went down? Answering that involves understanding a little about how flight-tracking sites work, where they get their data, and the limitations of existing technologies. It also involves appreciating a relatively new approach that the two large flight-tracking companies, Texas-based FlightAware and Sweden-based Flightradar24 are rushing to expand, a global sensor system known as ADS-B, which broadcasts updates of aircraft GPS data in real time. ADS-B is slowly superseding the ground-based radar systems that have been used for decades, becoming central not only to flight tracking but also to the future of flight safety. And it's powered, in part, by thousands of dedicated aviation hobbyists around the globe.

Comments

Too bad they're not more open...

[Anonymous Coward]

It's a shame that services like FR24 are not more open. A lot of people are contributing to the service for free - though some may get a free subscription in exchange - but then what happens to that data?

First, it gets massaged. Sensitive flights, flights operated by people who don't want to appear on FR24, etc.get removed. Alright, I can see how that makes sense - if for no other reason than that if they didn't, they'd probably be shut down pretty quickly.

Second, you don't get access to the data. You only get access to exactly what they want to present - be that with ads around, under a subscription payment, or via apps, etc.

As an example, another app that gave superior AR results (point smartphone at sky, identify what plane is leaving what control) was shut down because FR24 didn't much appreciate them using the data off of the site - leaving users instead with the inferior FR24 AR.

However, the same applies to any other item. Would you like an alert whenever there's a rare plane passing over? Sorry - you can't do that. It would be easy to code, but you don't get access to the data.
Do you want to accumulate flight paths for an image of how flights appear around an airport? Easy to code, but no access to data.
See a flight that has no apparent destination, but you just know that if you look for similar flights along similar flight paths in the past, you could probably get a good idea of where it ought to be going - well unfortunately you can't do anything with that knowledge, because you get no access to data.

In more recent times, FR24's website has become less and less usable as things get tabletized - which you could fix by building a new site, but, of course, no access to data.

"Don't they have an API?"
No, they don't. The only API on their site is the string "API" in certain plane registrations.

Sure, you can access some of the data that's public by necessity of app limitations, but at the very top of the JSON output you'll find a message about how it's copyright and only for use by FR24 and if you use it for yourself they'll happily sue your ass, etc.

Of course, you could set up a rival website, but then you still need people feeding you the data - and it seems most of them are more than content with only feeding to FR24.

For something that is almost entirely dependent on semi-voluntarily provided information by the public, it's a shame that they cannot give back more to the public other than a premium subscription, and instead tries to monetize the data as much as they can; even their paid app ($3.50?) has in-app purchases for things like "Realistic aircraft symbols" - the same symbols that were available for free before... in the free app.

tl;dr: While sites like FR24 have popularized crowdsourcing of flight data, they have simultaneously crippled the potential of that data.

Works great when you want to be seen

[steve-san]

"ADS-B is slowly superseding the ground-based radar systems that have been used for decades"
... until the aircraft decides to become "uncooperative" and turns the darn thing off -- at which point, this (and any beacon/transponder-based system) becomes instantly useless.
Which is why you'll see ADS-B augment, but never completely replace old fashioned search radar anytime soon.