I've built an outdoor ADSB aircraft position tracker on a budget! It uses a Raspberry Pi, two SDR USB receivers, two homemade antennas and an inexpensive enclosure to house everything on our roof.

Instructions for PiAware:
https://flightaware.com/adsb/piaware/

SDR Receivers for 1090 MHz and 978 MHz:
https://www.amazon.com/FlightAwareFA...
https://www.amazon.com/FlightAwarePr...

Plastic box:
https://www.harborfreight.com/030cal...

Make your own antennas:
https://lucsmall.com/2017/02/06/makin...

1/4 Wave Ground Plane Antenna Calculator:
https://m0ukd.com/calculators/quarter...