[time-nuts] List of time synchronization hardware and software

Magnus Danielson cfmd at bredband.net
Tue Jan 17 19:01:19 EST 2006


From: shoppa at trailing-edge.com (Tim Shoppa)
Subject: Re: [time-nuts] List of time synchronization hardware and software
Date: Tue, 17 Jan 2006 17:20:40 -0500
Message-ID: <20060117222040.8794FBA4840 at mini-me.trailing-edge.com>

> "Poul-Henning Kamp" <phk at phk.freebsd.dk> wrote:
> > Pulsars were considered for timekeeping several times in the past, and in
> > every instance the winning argument was "You want to base our timekeeping
> > on some cosmic phenomena we don't even know what is ?".
> 
> Well, look at how dependent NTP and navigation and telecommunications
> is on GPS sats today. There the uncertainty isn't the technology but
> the military/government/funding/infrastructure behind them. Glonass
> helps, as will Galileo. I'm a little surprised there aren't more
> Glonass receivers out there (they seemed confined to a segment of
> the surveying population although maybe my view isn't quite as global
> as it should be.)
> 
> The threat isn't quite as big as the funding to the IERS = International
> Earth Rotation Service. Cut off their budget and the earth may stop
> turning, it's almost as bad as the Philosopher's Union!
> 
> Seafarers happily used astronomical fixes (along with a good
> chronometer) for many years long before we understood stellar dynamics.
> Full understanding of a phenomena is hardly necessary to use it as
> part of a tool. That said, I think we understand pulsars a little
> better than we did at first discovery (where the LGM hypothesis seemed
> to stand out...)

Eeeeehum... have we been able to separate the time meredian from the
navigational meredian such that a free-drifting UTC will not affect the ability
to navigate? I surely hope so, or we will have a big problem here...

I don't know the details, but it is reasnoble that the GPS reference stations
positions in WGS-84 will keep the GPS coordinate system locked correctly.
Time to read-up on the WGS-84 coordinate system and its relations to time-
scales again. They do relate one way or the other.

Cheers,
Magnus




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