Frequency Reference for NTP Use?

Wally wally at
Sun Jul 14 21:15:06 EST 2002

I guess the question to ask is how accurate do you need it?

If you sync the PC's clock at the start ... How much drift is acceptable
after week? or after 1 month?

> -----Original Message-----
> From: Alex Satrapa [mailto:grail at]
> Sent: Sunday, 14 July 2002 5:46 PM
> To: Tomasz Ciolek
> Cc: Brad Hards; CLUG Mailing List
> Subject: Re: Frequency Reference for NTP Use?
> On Sunday, July 14, 2002, at 12:37 , Tomasz Ciolek wrote:
> > But why? talk the csiro in Sydney. they have a cesium clck 
> level2 and
> > level1 NTP master sites. Maybe they'll let you get a feed?
> I want a system that will be autonomous.  It should be able to last a 
> week without external synchronisation, and still be able to 
> be inserted 
> into a UTC coordinated network without time-dependent stuff breaking 
> (eg: make, mail, time stamping).
> In one instance, I might want to have a device that is mobile 
> and only 
> ever in transient contact with The Internet or the GPS sky - for 
> instance if I have a data logger that lives in a cave surrounded by 
> metres of granite.  Or a combat control system that lives on 
> a submarine.
> It's pretty much an academic exercise at present, since I 
> don't have any 
> real need to fulfill.  I was at one stage curious about what 
> I could do 
> with my consumer GPS receiver (designed for hiking or boat 
> navigation) - 
> and clearly it's not suitable for use as a reference clock since the 
> hardware required to discipline the clock is more expensive than a 
> commercial GPS receiver designed with reference clock duties in mind.
> Alex

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