RTL-SDR and RDS Spy with HDSDR
On YouTube user pe1etr shows us a video where he uses his RTL-SDR combined with HDSDR, Virtual Audio Cable and RDS Spy to decode a distant RDS signal. RDS Spy is a free advanced software program capable of decoding weak RDS signals contained in many broadcast FM radio stations.
RDS stands for Radio Data System and is a digital signal embedded into broadcast FM signals. It is used by radio stations to display the name of the radio station and current song playing on an LCD screen.