[ntp:questions] Re: Good GPS for attic?

jimp at specsol-spam-sux.com jimp at specsol-spam-sux.com
Tue Feb 15 22:36:58 UTC 2005

In comp.protocols.time.ntp David Magda <dmagda+trace050112 at ee.ryerson.ca> wrote:
> jimp at specsol-spam-sux.com writes:

> > Not to mention it is rapidly becoming the primary means for
> > aviation navigation and instrument approaches, all with the
> > blessing of the US government.
> > 
> > In the very near future, shutting it off WOULD be chaos for
> > aviation.

> This was only done because the US assured the people in charge of
> international aircraft navigation that they wouldn't turn it
> off. (I'm sketchy on details since I was never able to track down a
> primary source for this (supposed) fact.)

I was referring to US air navigation.

The FAA wants to reduce the number of ground-based navigational aid
approaches in favor of GPS-WAAS approaches.


GPS is making slow inroads for precision air navigation outside the US,
probably mostly because it is a US system.

> However, with navigation there is still the backup of intertial
> systems. If accurate time is important to someone, they would
> probably have a backup atomic clock. There's also WWVB and CHU for
> those in North America.

Few, if any, aircraft flying domestic routes have intertial systems.
The backup is the VOR stations and there are rumours of phasing them
out in the US sometime in the future.

The new 406 MHz aviation emergency locator transmitters which will
become mandatory in the US in the future contain GPS receivers to
pinpoint location.

Switching to marine navigation, Germany is closing lighthouses in favor
of GPS.


The Canadian Coast Guard is pushing the Differential Global Positioning

I could go on and on about applications a bit more important than the
correct time.

The bottom line is that GPS has become so essential to safety related
systems that Pandora's Box has been opened and shutting off GPS for
anything of lesser consequence than WW III will be chaos, people
will die and not very likely to happen.

Jim Pennino

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