comments:
For SDR I would recommend a pluto clone like a Plutosky or Pluto+ they work great for ads-b and if you configure it correctly you can use both RX ports so you can have a omni antenna and a yagi pointed to a corridor. The unit it self can do the decoding and feed to flightaware, flightradar etc so all you really need is a ethernet cable and all and a poe injector/splitter and you are pretty much done.the SDR is on the network you can monitor it localy or you can pretty much port to any homebase you want!Both RX and TX are on the same oscillator so you can't choose diffrent frequenciesthe plutosky has gpio ports so you can program those as well. It is also very wideband SDR so you can do a lot of satellite work with them. And for GPS/GNSS I would get a Ublox M10 drone GNSS module and a USB serial adapter ch340 or cp2102 both work with the Ublox module they are dirt cheap I always used a old laptop running linux as my nodes so I would recommend something like a mini pc with a AMD cpu as raspberry pi's are just as expensive and you get a little more oompf. And a big electrical panel box works great or one of these metal project boxes I've had a node running almost 3 years survived 2 hurricanes and then the dust killed it....