GPS Jamming/Spoofing Threat

[0TreeLemur]

1 hour ago, EricJ said:

Aka Differential GPS.   It's been around for a long time.

https://en.wikipedia.org/wiki/Differential_GPS

 

 

Yes- I've used it on a tractor and for surveying.  As @tmo pointed out, probably best to be in a different frequency band.

[afward]

On 2/3/2021 at 2:43 AM, tmo said:

when you fly high enough, you are unlikely to have any cell reception

Realistically, a receiver would only need to be able to pick out the timestamp and location (or tower Id to look up in a database) out of the noise.  20W or so can carry a really long way if you don't need a lot of signal to noise margin.

The big problem with using cell towers is the frequency range required: The bands start at 617 MHz and go past 24.25 GHz.  Not gonna be a viable option for most light planes (unless someone can figure out how to bend the laws of physics).

We already have a good option: FM, TV, and VOR all have identifiers built into the signals, and they all transmit with plenty of power to reach many miles at altitude.  The only downside is one might want multiple antennas so direction and precise frequency can be determined (mitigating it is the size: a fractal antenna covering the whole range would only be about 6"x6").