In North America ADS-B is pretty rare except on the coasts where international flights pass through more frequently. If you are not on the coast and look at the

In North America ADS-B is pretty rare except on the coasts where international flights pass through more frequently. If you are not on the coast and look at the logs of your flightradar24 receiver you will see that 99% of the traffic are MLAT rf direction finding logs from mode-S transmissions with no GPS data used. But it's still easier to call it an "ADS-B" receiver because no one knows that MLAT is.