Re: [chrony-users] Application requires frequency accuracy but not time accuracy

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On Sat, Sep 28, 2019 at 04:20:38PM -0400, Brian Morgan wrote:
> I wish to thank Professor Unruh. He inspired me to take a deep dive into my
> chrony.conf file. As a software developer and devotee to the concept of
> "minimal completeness" I have arrived at this:
> 
> driftfile /var/lib/chrony/drift
> makestep 0.1 3
> refclock SHM 0 refid GPS poll 7

That looks good to me. You could add there corrtimeratio 1000. That
would make the frequency more stable, but if I understand the previous
emails correctly, that might not actually be what you need.

Setting minsamples and maxsamples for the refclock could improve the
phase or frequency accuracy. But we would need to know how much wander
the clock has (how unstable is temperature) and how much jitter is
there in the GPS samples. 

> I am a great believer in sharing knowledge. Many astrophotographers keep
> their "secrets" to themselves. I, on the other hand, like to share. I'd like
> to offer you my website so you can follow my progress. My latest subject is
> the Andromeda Galaxy:
> 
> https://astrotuna.com/andromeda-galaxy-m31-the-saga-continues-siril-app/

Very nice. To better understand the requirements on accuracy, how many
milliseconds is one pixel in that image?

-- 
Miroslav Lichvar

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