Comment by Nextgrid

Comment by Nextgrid 4 days ago

4 replies

Surely the receiver would run plausibility checks on the received messages and reject spoofed locations that are physically impossible to receive by said receiver?

mschuster91 4 days ago

> spoofed locations that are physically impossible to receive by said receiver?

Wait until you hear about Sporadic-E or Aurora. RF is a weird place full of natural phenomena making the impossible very possible.

  • Nextgrid 4 days ago

    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 3 days ago

      > 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 3 days ago

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