ADS-B
I maintain the K2XAP feeder node that listens to ADS-B 1090ES and 978UAT messages from aircraft, passing them on to adsb.fi.
Hardware
The node is a Raspberry Pi 4 running ADSB.im with a pair of Nooelec 1090 and 978 SDR receivers listening through a 5.5dBi 1090/978 antenna, and an RTL-SDR with a 1090 antenna.