http://quantumagvxei55qyvhlj3zljkjryzzvvgckynsfr4r7tqgmiufj75qd.onion
I quickly looked at the requirements for Flightradar24 and found it wasn’t
even that much—all you need was a Raspberry Pi, a view of the sky, and a
cheap DVB-T TV tuner, such as the very cheap and popular RTL2832U/R820T
dongle, which has a software-defined radio (SDR) that could be used to
receive ADS-B signals.