[Nextgrid]

But even if that was the case, is there any value for a receiver to be receiving those? Surely those messages would be picked up by a receiver closer to the transmitter anyway. I think the value in spoofing rejection is greater than the probability of a transmission reflecting from beyond the horizon and not being already being picked up by a local receiver.

[mschuster91]

> But even if that was the case, is there any value for a receiver to be receiving those?

Yes, radio propagation is an entire academic field to be studied :)

In addition, if you have enough receivers you can use that to run something called MLAT [1] to also pick up GA aircraft that just have a transponder but no GPS. The more the merrier.

[1] https://adsbx.discourse.group/t/multilateration-mlat-how-it-...

[jjwiseman]

These receivers mostly don’t have gps and it’s very common for people to put in the wrong coordinates.