The Raspberry Pi is an amazing piece of kit. There’s little it cannot do with sufficient tweaking. I have a passing interest in planes, and love FlightRadar24 (iPad app and website).
FlightRadar24 screenshot
I started to wonder how they got this data. A quick rummage around their website reveals they mostly rely on a world wide network of volunteers to collect and then feed them data. You need ‘line of sight’ to an aircraft to be able to query the information, and no one entity can afford to do this globally. So, a network of volunteers run ‘feeder radar stations’ (ok, it isn’t really ‘radar’ but, more the Next Generation version of).
Hardware I Use
I use a ‘stock’ Raspberry Pi model B, connected via ethernet to my home network ordered via RS Components (fwiw, they’re slow as heck… order one from somewhere else…!). My Pi is strapped up under my desk out of the way. It has a 4 port (unpowered) USB hub connected to it (the black blob underneath) but otherwise it is entirely unremarkable. I’m even still using the original RS Components 4Gb SD card.
Excuse my camera charger lurking underneath it all – it’s entirely unrelated!
My Raspberry Pi, mounted under my desk
Hardware wise, to receive the ADS-B broadcasts from planes overhead, I use a DVB-T (R820T) Stick with an external aerial attached to it. I ordered mine from 1090mhz.com (based in Germany) and it arrived in the UK about 4 days later in perfect condition, and even had an adaptor and external aerial included in the package – thanks guys! This is the ‘best’ stick to use – apparently – as it is based on the R820T chipset.
Software I Use
I use a modified version of dump1090, originally installed using instructions from David Taylor’s SatSignal.eu website. dump1090 is fantastic. Using the sdr-rtl drivers (also documented on David’s site) to re-tune my DVT-B Stick from digital TV to the 1090MHz used by ADS-B, allows it to receive the ‘next gen’ radar data right from the planes in the sky themselves.
dump1090 then takes this feed and decodes the data into something human rather than machine readable. Using the –interactive mode, you can see the output as the planes fly by.
dump1090 –interactive
Perhaps even more exciting than that though, is the –net option, which enables not only all the data sockets so that FlightRadar24’s software can pull the information out of dump1090 (setup instructions here), but also enables a built-in web server so you can run and view your own miniature version of FR24:
Screenshot of my own ‘dump1090’ FlightRadar24-style output (–net option)
MySQL Support
You may remember I said I use a modified version of dump1090. That is because as well as everything above, I also wanted to store a local copy of all the data I receive in a MySQL database so I can do my own manipulations and calculations. While there is a MySQL’d branch of dump1090 on github, it is dozens of commits behind the main branch and missing out on a lot of the hard work Malcolm Robb has put in to his master branch and fork of antirez’ original work.
So, rather than forego either mysql, or using the latest version of dump1090, I hacked them together and re-introduced mysql support into the latest version of dump1090.