433mhz weather station protocol?

There are lots of problems with decoding an unknown RF packet format if you want to recreate it over the air:

The things that you need to identify are:

carrier frequency
modulation type
deviation (if FM)
baud rate
manchester coding, whitening, bit-stuffing or other clock-recovery feature present.
preamble and header, CRC algorithm

I'm wondering how you know your rx433 unit is actually picking up the correct signal and not some other 433MHz device?