Flightradar24 is a great site that allows you to track planes, we all know of it - unless you have been living under a rock for years.
But how do they get the planes transponder signals back to there severs in real time for us to see live?????

Well you can apply for a receiver station from them, and if you get one just plug it into your wifi/lan and shove the antenna out somewhere high.
https://www.flightradar24.com/apply-for-receiver

But you can build your own.
https://www.flightradar24.com/build-your-own

Of course a pi of some sort is required for this with a SDR dongle and antenna, the sdr kit can be found on amazon for like 12 quid and most pi's can do this easily.
I used an orange pi as i had it floating around, i have a bannana pi as well as an odroid xu4 and several raspberry pi but i wanted to use the orange pi zero as its fecking dinky at literly 2or 3 cm square and holds a nice fat quad core, 1 usb port (all i need but i do have an expansion card for it if i want more ports) and an rj45 network port.

Setup of the orange pi is almost as easy as the raspberry pi version, but FL24 actually gives you a fully enabled and configured raspberry pi image to download however they also have a repo for the FL24 SW that can be straight up installed onto most linux builds.

So its easy to setup and you will be left with a page looking like this from a webbrowser on your lan pointing to the pi and its interface



And from FL24 radar display on there public page




Mine has been up a few days but had a couple of probs, dhcp went back on when i did a repo update and i didnt notice so it lost its static IP And you need that for FL24 to talk to it so dhcp users set a static address or lease.

Ohh and as a contributor you get a free years worth of the business FL24 package.
So put your pi to work and get plane tracking.