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opencomputeproject / Time-Appliance-Project

Develop an end-to-end hypothetical reference model, network architectures, precision time tools, performance objectives and the methods to distribute, operate, monitor time synchronization within data center and much more...
MIT License
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Is GNSS dependance the mistake? Should part of this include back to basics. Solar/moon calibration. #69

Open oiaohm opened 1 year ago

oiaohm commented 1 year ago

https://hackaday.io/project/167202/instructions Aweigh here was working on calculation current location using sun location. Of course reverse can be done using sun/moon... to calculate time.

GNSS can be spoofed or jammed. Local time calculated by sun/moon is a lot harder to jam and can be hard to spoof.

Back to basics of calibrating atomic clock straight from sun/moon. Yes using GNSS when the signal is good to work out what the local offsets are.

Its just that thing I got thinking this has added atomic clock to fix the issue that GNSS is not dependable. Reality here GNSS is still not dependable. This got me thinking is there some other clock source that is dependable. Then I remembered that our clocks historically were calibrated by sun and the sun and moon and stars... are all still there.

Raspberry pi compute module with like Aweigh module on poe Ethernet cable in a water proof box on roof is possible. This way if GNSS is jammed or spoofed for a long time atomic clock calibration can be done at-least once per day against the sun. This could removes the GNSS dependence reducing so making it optional extra. Dependence comes sun and atomic module.

See my problem here is the time board working around problem that can be avoided. Time of year and other things are also calculable from sun location in sky to earth position information this could also limit spoofing of GNSS information being able to check against local sun time/data.

I know the sun/moon data will have some error due to how land under our feet slowly moves.

ahmadexp commented 11 months ago

@oiaohm, sorry for getting back to you after a year. I just noticed this comment and I find it very interesting. Things that I am not sure about are, the precision you will get form observing the sun and wether it is good enough to be in the useful to discipline an atomic clock. The introduction of VLBI made use find out about leap seconds while before that we had no clue about precisions lower than 10ms per day (this number is just a guess though). I love to hear more about your thoughts.