A lot of people have combined a RasPi and a SDR dongle to get a low power
consumption ADS-B tracker. Tomasz Miklas
has created an image for the Raspberry Pi, that has everything that is needed
to run your own aircraft tracking “service” already set up. I’ve finally had a
chance to experiment with it and this will be my short review.
First of all, I have to say I’m really sorry to Tomasz, because he send me the
image at the 10th of October to test it out before releasing it publicly and
I’m posting this two months later. Sorry mate.
Tomasz, has a well written post explaining how the image works
, so I’ll skip the details. All tests were performed using a dongle with a
R820T chip and the stock omnidirectional antenna. Since I moved recently, I
didn’t have the time to construct a proper antenna, yet even with such an
antenna the result were pretty good.
So, you download the image,
dd it to a SD card, plug your SDR dongle, power
it on, point your browser to the IP the RasPi obtained through DHCP and … and
everything simply works out of the box. At least it did for me.
I was really surprised by how lightweight the whole setup was. After one and a
half hours of uptime, two clients connected to the server and, receiving
messages from two planes, the RasPi reported that it only used 30 megs of RAM
and the CPU was pinned at 35% the whole time, with 4-5% of it being htop
itself. The process using the CPU was of course dump1090, which does all the
heavy lifting. Unfortunately, due to the time I tested the image (4 AM) and my
location, there weren’t many planes (two simultaneously at max), so I don’t
know how dump1090 behaves under a lot of load/traffic.
As mentioned above, I was using the stock antenna that came with the SDR
dongle, but I was still able to get a signal from planes that were 72km away
on average! On some of my previous tests under Windows and ADSB#, I only got
28km of range. A lot of things have changed since then though, mainly my new
house and my antenna placement, or perhaps the old one was a
Faraday cage? Either way, for the
time being, I’ll leave the RasPi running and further report on its performance
after a bit of testing.
If you own a RasPi and a SDR dongle, give the image a try. It may not be
something you haven’t seen or done already, but it certainly is the easiest
way to monitor ADS-B traffic, at least to my knowing. I know, I’ll be keeping
a copy of the image in a SD card because it’s so handy.