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DoctorOetkeryesterday at 2:48 PM1 replyview on HN

nobody would send a military vehicle (manned or drone) without initializing a proper clock, the replays would be stale.


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eqvinoxyesterday at 4:12 PM

You're overestimating how precise the clocks in normal electronic devices are. A typical PC clock is +/-100ppm. After 1 hour that's 0.36s, which is roughly 100km in distance. A good electronic clock is a tenth that. An OCXO is in the 1ppm range, but that's still a kilometre per hour.

There's a reason GPS satellites are used as reference clock for PPS, PTP and NTP. A naval vessel you could carry a Rubidium clock on, I guess. But on ground vehicles or mobile receivers... nope.

[ed.: OCXOs aren't that large, 1cm^3 box ballpark, too large* for a smartphone or laptop but not a problem on larger quadcopters, cars or military radio equipment. And 1ppm is long term drift, you can try compensating a bit beyond that, so - I guess it's a question of spending the money and energy** on OCXOs.

* thick specifically, can't easily be made thin AFAIK

** the first O there is Oven - roughly 0.5W continuous draw.]

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