[touisteur]

You can get a very accurate timestamp from GNSS. What lots of people do then is slave a PLL based on a local oscillator, to be able to get time between two GNSS captations. Or to be able to extrapolate when they have no GNSS signal.

Now suppose someone is spoofing your GNSS signals, it's pretty hard to replace a constellation with another one whilst maintaining time consistency for you. One way to detect spoofing is comparing what a local clock is saying to whatever the GNSS is giving. A local, unfudgeable, stable, accurate clock is a good reference for this.

[DannyBee]

The article is seriously confused. What you are talking about is easy - chip scale atomic clocks are easy to get. I can have one shipped to me today. Hell, i have one on a time card in my basement.

Assume you want it even super accurate.

Great, 3k for an SA65 https://www.microchip.com/en-us/products/clock-and-timing/co...

Holdover would be fine for even a very long flight.

Hell, even a good rubidium oscillator doing 1PPS will stay within 200 nanoseconds over 12 hours.

If you are trying to do navigation while jammed, none of these help you.

You still need good reckoning, which is the hard part

We done solved the clock problem enough already :)

[touisteur]

I was under the impression (and from experience too) that the very stable oscillators were finicky and sensitive to temperature swings and in general costly to use properly in "hard" environments.

I'm happy to learn this is not the case for every good oscillator. TIL.

[thesh4d0w]

Ahhhhh, that makes sense. Treating this as security mechanism rather than an anti-jamming one.