If you have been following this blog for the past few weeks, you probably know my feelings about people that are using the Raspberry Pi for what I consider to be inappropriate uses. (Hey, pay attention, I mentioned it yesterday!)
Projects like laptops, cameras and such….. I have called these small computers a solution looking for a problem.
To me, the whole point of a small low power, low capability computer is to find a job where it can just sit and do something that is out of the reach of most off the shelf electronics.
After looking at things for a bit, I think I found just such a job for me……
Aircraft tracking.
I have always been interested in radio, antennas and have really missed tinkering with them.
After all my years as a licensed amature radio operator in Australia, I knew that I was not really interested in talking to people any more (plus the whole accent over the phone = not being understood thing), but my interest has been really peaked with the ‘new’ digital modes.
My love of computers, radio, digital signals, loving all things aircraft and being an introvert finally came to intersection with my discovery of SDR, ADS-B and Raspberry Pi.
We know about the Pi, so lets look at the other two.
SDR is Software Defined Radio. In a nutshell it means that a computer (aka software) has a lot more control over the radio than a human could. In other words, raw data about the signal can be passed to the computer for it to process and decode rather than just audio into a human ear.
This is the breakthrough for a lot of digital modes. Now, alls one has to do is write some software and you can gain access to all sorts of digital modes/information.
But what about the radio itself?
Ah, enter the hacker. Some very clever people figured out how to get raw data out of a TV USB receiver.
In other words, they have found out how to take a small 20 buck device and repurpose it for something it was not meant to do.
Rather than using it to watch TV on a computer (who does that anyway?), it passes the raw data of the signal into the computer for decoding.
Lastly then, we have ADS-B.
Aircraft (not all today, but almost all – and all in due course all aircraft will be required to) have a transponder on them. A simple ‘dumb’ beacon that spits out who they are, where they are (using their onboard GPS) and how high they are.
This data can be picked up by a radio receiver tuned to the right frequency (1098mHz).
Put all this together and you get what I have got going over the past few days…….
In the roof space I have zip tied a Raspberry Pi computer to a rafter, put a USB TV receiver stick into the Pi and a small stick antenna, the Pi is on my network and uploads its received and decoded aircraft transponder data to two different flight tracker services.
Perfect use for a small single board computer. It runs Linux and decodes the data and other stuff.
It’s low power, it’s low maintenance, it’s just cool.
There is some data on my website, it’s on the page right at the end of the menu. (Not all those aircraft are tracked by me, they are all the planes in the database).