In one of my favorite YT videos ever he talk about how he design RF PCB. The point of it is kind of like, the field of RF and SDR is incredibly deep and complicated, but at the same time, most filters/mixers/amplifiers and everything else needed for making an SDR are ICs that one can buy from Digikey and put them together (or likely have assembled).
So, not denying how deep SDR can be, but it can also be accessible with enough effort!
Understanding the frequency domain, why it's useful, and how to get there & back, is like 80% of the puzzle.
Sorry just trying to get more detail out of you and apply it towards some code to make it practical. :)
https://www.tindie.com/products/hcxqsgroup/4-nanovna-v2-plus...
LimeSDR are a bit more involved, but like most SDR transceivers still need band-pass filters and power amplifiers to perform well. Works well when combined with a GPS locked 10MHz GPSDO like a BG7TBL. =3
Do you get this information from radio waves? would love to know more about your setup.
Such weather stations were really commonplace 20 years ago, I remember my grandparents having a sensor outside and a basic LCD display in the kitchen displaying the outdoor temperature and humidity. These days we want that data digitally on our phones or home assistant so you need a receiver that talks TCP/ip and runs a real os. That's where the SDR comes in to bridge the gap between primitive RF Tech and modern computing. Of course you could also put an esp8266 outdoors, which natively talks wifi, but then you lose range and your battery life goes from years to weeks.
There are several frequency ranges in the US that are unlicensed for transmission. But don't confuse unlicensed with a lack of rules governing what you are allowed to transmit; how often you can transmit and for how long. Because you can plop a 433MHz transceiver into anything, you want to be careful that you're not clogging up the local airwaves by not knowing to know the rules. Also, most smart meters (near me anyway) operat in this band sending out pulses every so often. They mesh together to relay the data towards a central collector. Thanks to that low frequency, hundreds of meters can be visible at times showing up as tiny chirps all over this area of the spectrum. Unfortunately this also means that some cheap receivers (just looking for any signal on a very specific frequency in that range, can be randomly triggered by this 'noise'. But also, because it's used by utilities, to want to make sure they don't end up having an issue with meter readings because you began running a wifi link over 433MHz.
It's open source, and you can just play with your audio ports for starters. Later adding a $40 rtlSDR kit goes a long way. I used mine to build a VOR receiver.
I built a gnu radio flowgraph to receive both and display heading to the VOR.
I know almost nothing about actual SDR, but I've got a cheap SDR receiver/antenna inside a glass basement door that receives temp/humidity data from ~10 433Mhz transmitters in various rooms in my house + outbuildings, and a weather station that reports temp/humidity/lignthing strikes/rain amount/wind speed+direction, and lux. All that goes to an influx DB instance, and has a set of graphana dashboards built on top of it. Took me a couple evenings to get set up, and now I've got real time + historical environment data about everything I care about at my house; including high humidity alerts in rooms with dehumidifiers, freeze warnings for a crawl space, and a bunch of other stuff. It has been wildly reliable.