As well as NIST there is Schriever spave force base https://en.m.wikipedia.org/wiki/Schriever_Space_Force_Base which is the ground operations centre for GPS. They have the USNO alternate master clock, which maintains a copy of the USNO time scale based on caesium beam and rubidium fountain clocks.

Sadly the cache files don’t record enough about the environment to be usable if you change configure options. They are generally unreliable.

The NASA page does not make the false equal time assumption.

You are thinking of John Meacham’s winning entry in the 2008 underhanded C contest https://www.underhanded-c.org/_page_id_17.html

Wow, it took me a minute to figure out how his entry works. You really could read that code and assume it was correct. The resulting image is perfectly redacted visually, and the missing data is not appended or hidden elsewhere in the file. You would only discover it by inspecting the PPM image in a text editor. Very sneaky!

Portable clocks are not better than static caesium clocks, and optical clocks which are better than caesium clocks are not portable.

Eh, not smartphone-like portable, sure, but publicly (https://english.kyodonews.net/news/2025/03/c0945eb14bb6-japa...) it can now be fitted on a ship or submarine (and I won't be surprised if there is classified miniturization out there).

Also very good is “The Scariest Library” https://www.exurbe.com/the-scariest-library/

I hate to helk, it’s a G-noo. https://youtu.be/j53z6RfFb7U

The incorrect results are far more important than the times!

I agree.

Cloudflare provides free hosting to booters and stressers.

The article is deeply confused.

It’s true that optical clocks will improve the accuracy of our measurement of time, and it’s true that GPS depends on time, but there are several steps between primary frequency standards (ie, optical clocks) and GPS, and several more steps between GPS and navigation applications.

So optical clocks cannot, in fact, have any effect on the end-user perceived reliability of GPS.

For that, the best solution is to revive LORAN which is much less susceptible to jamming. (And would also benefit from better atomic clocks.)

Much of Finland and Estonia are currently being jammed per https://gpsjam.org/?lat=58.53948&lon=24.82400&z=4.9&date=202...

Finland is reintroducing DME: https://www.reuters.com/business/aerospace-defense/three-fin...

Which seems to be a different concept from LORAN, but still useful for navigation when multiple base stations are in range.

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