FYI...
---------- Forwarded message ----------
Date: Fri, 11 Sep 1998 10:33:32 -0400 (EDT)
From: Nick Eiteljorg <[log in to unmask]>
Subject: AIA LIST DIGEST GPS and Y2K problems 98-99-f-25
AIA LIST DIGEST GPS and Y2K problems 98-99-f-25
Date: Friday, September 11, 1998
Messages included: 3
Subjects: #1: Arch-Comp: Magellan Trailblazer GPS and Y2K (20 lines)
#2: ARCH-L Re: Magellan Trailblazer and Y2K (27 lines)
#3: ARCH-L Y2K and GPS (45 lines)
Unless marked as originating from the AIA, messages neither represent
Institute pronouncements nor imply Institute support or endorsement.
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Date: Thursday, September 10, 1998 1:54 PM
From: David L. Carlson [[log in to unmask]]
Subject: #1: Arch-Comp: Magellan Trailblazer GPS and Y2K (20 lines)
A couple of years ago I purchased a Magellan Trailblazer GPS for survey work.
Today I received the following letter from Forestry Suppliers (who sold it to
me):
"Magellan Systems has advised us that the Magellan Trailblazer GPS and the
Magellan Trailblazer XL GPS receivers will fail in the year 2000. The failure
will be indicatd by the completed [sic] system shutdown of the trailblazer GPS
series receiver. Magellan has regretfully informed us that there is no
solution to the problem."
Granted it was an inexpensive system and I appreciate Forestry Suppliers
letting me know in advance, but I certainly didn't expect that Magellan
Systems would be shipping equipment with a built-in 4 year lifespan.
Does anyone on the list have any information about this? Magellan Systems
Web page doesn't have any information.
David L. Carlson, Associate Professor of Anthropology, Texas A&M University
College Station, TX 77843-4352
(409) 847-9248
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Date: Thu, 10 Sep 1998 13:19:58 -0500
From: Fazia Begum Rizvi <[log in to unmask]>
Subject: #2: ARCH-L Re: Magellan Trailblazer and Y2K (27 lines)
This was a response to Mr. Carlson’s query. <TILDE> has replaced that character
in the following addresses. -- ed.
I wasn't able to locate any information about the Magellan Trailblazer GPS
and Y2K problems, but I'll let you know if something does fall into my
inbox. (I'm working on my University's Y2K website.) I don't know if it
will help much since you're looking for information on that particular GPS
system, but I did find a couple of web articles that talk about Year 2000
problems and GPS systems in general:
The Y2K or Millennium Bug and the GPS Bug:
http://www.sustainableworld.com/y2kgps/
Global Positioning Satellite (GPS) Risks Associated with the Year 2000
Problem:
http://www.indymall.com/oldies102/nettalk/y2k/gps-y2k-risks.htm
A couple of links:
http://plaza22.mbn.or.jp/<TILDE>Platon/y2k.html#gps-system
Is the Year 2000 GPS "problem" REALLY a Problem at all?
http://www.bridge.de/<TILDE>tom/Y2000.htm
ad astra,
-Faz
Fazia Begum Rizvi [log in to unmask] http://www.uh.edu/<TILDE>frizvi
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Date: Thu, 10 Sep 1998 15:22:57 -0500
From: "Mark L. Anderson" <[log in to unmask]>
Subject: #3: ARCH-L Y2K and GPS (45 lines)
Dear David and List,
Opps, guess I didn't read far enough in the L.A. Times article of 8-17-98.
Below are the specifics on GPS from that article.
Sincerely, Mark.
The Global Positioning System, a network of satellites used to
establish navigational positions, was developed by the military
starting in the early 1970s. The system uses a timekeeping system
that works on a 1,024-week cycle, which ends in 1999.
The length of the cycle, known as an "epoch," was kept at 1,024
weeks because it could be transmitted in a frugal 10-bit block.
One extra bit would have extended the cycle for an additional 20
years. Two extra bits would have pushed the epoch out to 2058.
The current 1,024-week cycle will end Aug. 22, 1999, and for a
period, perhaps as long as a week, some of the satellites will be
separated in time by 20 years. Many receivers will be unaffected
by the change, but some will suffer a variety of problems, from
temporary shutdowns to minor burps in service.
Most modern receivers can be easily repaired with a software
update. Older receivers will work fine after all the satellites
are synchronized, according to GPS manufacturers.
Charles Trimble, the president of Trimble Navigation, one of the
largest manufacturers of GPS receivers, said the root of the
problem is that many people simply forgot about this one obscure
but critical detail of the GPS network.
"It's another one of the gotchas," Trimble said. "It's part of the
complexity of the technological age. There is no way we can know
everything."
Trimble said that if the government had originally cut the size of
the cycle to 10 years, or even five years, there would be no
problems, as engineers would have been more aware of the rollover.
But 20 years, he said, is just long enough for one generation of
designers to retire and be replaced by a new generation that
hasn't even heard the term "GPS epoch."
"By having the problem occur every 20 years, people just didn't
think about it," he said. The company has posted the necessary
repairs to its products on its Web site.
Mark L. Anderson
Project Archaeologist
Office of the State Archaeologist
700 Clinton Street Building
Iowa City, Iowa 52242-1030
319-384-0730
[log in to unmask]
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End of AIA LIST DIGEST GPS and Y2K problems 98-99-f-25
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