Re: GPS

[Keith E. Brandt, M.D.]

Frank,
Check out http://www.space.com/news/gps_rollover.html for a newspaper-style 
story on the GPS rollover, due to occur 22 Aug 99.


Keith

At 13:11 8/16/99 , you wrote:

My wife half-heard a piece on the radio this morning saying that GPS
instruments would fail next week unless they had previously been
modified to take account of some transmission changes.  They would
simply be unable to find a position.  Sound a bit like the millennium
bug.  Does anyone have any information about this, please?  Users were
advised to contact their suppliers.  I'm feeling lost already so can you
help?

Frank
--
Frank Evans


=
Keith E. Brandt, MD, WD9GET || Goodbye, cruel world that was my home-
 Resident in Aerospace Medicine ||there's cleaner space out here to roam.
San Antonio, TX || Put my feet up on the moons of Mars-
[EMAIL PROTECTED]||sit back, relax, and count the stars.
http://www.dca.net/~brandt  ||
=

Medieval dial question

[Keith E. Brandt, M.D.]

I am interested in medieval dials as were in use prior to the advent of 
clock time (up to mid- to late 14th century)


I am curious how dials were used in this period, as sundials are 
intrinsically equal-hour devices. I have seen numerous references that 
suggest that dials were among the methods used to determine when monks 
should celebrate the daily offices. Since these times would float (based on 
equal hours), there must have been someway they corrected for the varying 
hour lengths with the seasons, but have not seen articles detailing 
methods. References to English language works would be appreciated.


Thanks,
Keith


=
Keith E. Brandt, MD, WD9GET || Goodbye, cruel world that was my home-
 Resident in Aerospace Medicine ||there's cleaner space out here to roam.
San Antonio, TX || Put my feet up on the moons of Mars-
[EMAIL PROTECTED]||sit back, relax, and count the stars.
http://www.dca.net/~brandt  ||
=

Re: Coordinates for Rome

[Luke Coletti]

Hello,

You might try MapBlast (URL below) to zero in on the exact location
within Rome, if you have a modern street address you should be able to
get a precise lat/long.

http://www.mapblast.com/mblast/map.mb?loc=wo&worldres=&CMD=GEO&AD2=&AD3=Rome&AD4=ITA

-Luke

William P Thayer wrote:
> 
> Hello everyone,
> 
> I've looked for a longitude and latitude for *downtown* Rome (not the
> Observatory of Monte Mario) more precise than the usual 43N54 13E29, to no
> avail, both on the Web and in the few books of that kind available to me,
> and specifically that would correspond to a location on the Palatine,
> birthplace of Augustus. Can anyone help me?
> 
> Salve a tutti,
> 
> Ho cercato senza nessun risultato delle longitudine e latitudineper il
> *centro storico* di Roma (anziche dell'osservatorio di Monte Mario) più
> esatte delle solite 43N54 13E29, nel Web e nei pochi libri del genere alla
> mia disposizione, e specificamente che corrispondebbero a qualche sito sul
> Palatino, luogo di nascita di Augusto. Qualcuno potrebbe aiutarmi?
> 
> Grazie per anticipo/TIA --
> 
> Bill Thayer
>LacusCurtius
> http://www.ukans.edu/history/index/europe/ancient_rome/E/Roman

Re: GPS

[Richard Langley]

I wrote an in depth article on the roll-over for GPS World.  It's on their Web
site: http://www.gpsworld.com
-- Richard Langley
   Professor of Geodesy and Precision Navigation

On Mon, 16 Aug 1999, Keith E. Brandt, M.D. wrote:

>Frank,
>Check out http://www.space.com/news/gps_rollover.html for a newspaper-style 
>story on the GPS rollover, due to occur 22 Aug 99.
>
>Keith
>
>At 13:11 8/16/99 , you wrote:
>>My wife half-heard a piece on the radio this morning saying that GPS
>>instruments would fail next week unless they had previously been
>>modified to take account of some transmission changes.  They would
>>simply be unable to find a position.  Sound a bit like the millennium
>>bug.  Does anyone have any information about this, please?  Users were
>>advised to contact their suppliers.  I'm feeling lost already so can you
>>help?
>>
>>Frank
>>--
>>Frank Evans
>
>=
>Keith E. Brandt, MD, WD9GET || Goodbye, cruel world that was my home-
>  Resident in Aerospace Medicine ||there's cleaner space out here to roam.
>San Antonio, TX || Put my feet up on the moons of Mars-
>[EMAIL PROTECTED]||sit back, relax, and count the stars.
>http://www.dca.net/~brandt  ||
>=
>


=== 
 Richard B. LangleyE-mail: [EMAIL PROTECTED]  
 Geodetic Research Laboratory  Web: http://www.unb.ca/GGE/
 Dept. of Geodesy and Geomatics EngineeringPhone:+1 506 453-5142  
 University of New Brunswick   Fax:  +1 506 453-4943  
 Fredericton, N.B., Canada  E3B 5A3
 Fredericton?  Where's that?  See: http://www.city.fredericton.nb.ca/
=== 

Coordinates for Rome, thanx!

[William P Thayer]

Thanks to both John Komdat and Luke Coletti for suggesting MapBlast, which
I was unaware of, and which turned out to be something I can use in many
other ways as well. (He says, as he then busily adds to about 60 pages of
his website today!)

Bill Thayer
   Platner's Topographical Dictionary of Ancient Rome

GPS

[Frank Evans]

My wife half-heard a piece on the radio this morning saying that GPS
instruments would fail next week unless they had previously been
modified to take account of some transmission changes.  They would
simply be unable to find a position.  Sound a bit like the millennium
bug.  Does anyone have any information about this, please?  Users were
advised to contact their suppliers.  I'm feeling lost already so can you
help?

Frank
-- 
Frank Evans

Re: GPS

[Gordon Uber]

Frank,

The first GPS Week 1024 epoch rollover will occur at about midnight of 21-22
August.  The rollover occurs every 1024 weeks.  Date (and possibly time)
may be
incorrect for those GPS receivers that do not incorporate a workaround to
deduce the new epoch.  Before reading the pages below I had thought that
navigation was unaffected.  I think that recently manufactured receivers are
more likely to incorporate a workaround and to be correct during and after
this
rollover.

See
<http://www.2k-times.com/y2k-a118.htm>

More at
<http://www.laafb.af.mil/SMC
/CZ/homepage/y2000/> including a list of (primarily military) receivers that
have passed compliance tests for this and the Y2K problem.  If this rollover
presents a potential problem to you then contact your GPS receiver
manufacturer
(or their Web site) regarding compliance of your specific model and version. 

I think that a more complete Web search will locate much more on this problem.

Gordon


At 11:11 AM 8/16/99 , Frank Evans wrote:
>My wife half-heard a piece on the radio this morning saying that GPS
>instruments would fail next week unless they had previously been
>modified to take account of some transmission changes.  They would
>simply be unable to find a position.  Sound a bit like the millennium
>bug.  Does anyone have any information about this, please?  Users were
>advised to contact their suppliers.  I'm feeling lost already so can you
>help?

Gordon Uber [EMAIL PROTECTED]
Reynen & Uber Web Design http://www.ubr.com/rey&ubr/
Webmaster: Clocks and Time http://www.ubr.com/clocks/

Re: GPS

[Jim_Cobb]

> My wife half-heard a piece on the radio this morning saying that GPS
> instruments would fail next week unless they had previously been
> modified to take account of some transmission changes.  They would
> simply be unable to find a position.  Sound a bit like the millennium
> bug.  Does anyone have any information about this, please?  Users were
> advised to contact their suppliers.  I'm feeling lost already so can you
> help?
> 
> Frank
> -- 
> Frank Evans

This sounds familiar.  It's not a y2k problem per se, though it of a
similar nature.  I believe the issue is that a binary counter in the
GPS systems had few enough bits that they would reach overflow during
August 1999.  I believe the limitation is on the satellites
themselves.

I don't have the book with me from which I learned this (it's "The
Millennium Bug: How to Survive the Coming Chaos", by Michael
S. Hyatt), nor do I remember the precise date.  I will look tonight.
I believe that the book said that at the time it was written no
solution had been devised.  It sounds like this transmission
modification must be the fix that DoD devised (or perhaps the
transmission modification is simply the wrap-around of the counter).

I wonder whether early GPS receivers will be able to cope...

It reminds me of DOS's famous "640 K memory limit.

Jim
 --- -- 
| Jim Cobb  | 540 Arapeen Dr. #100 | [EMAIL PROTECTED]  |
| Parametric| Salt Lake City, UT   | (801)-588-4632 |
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 --- -- 
Familiar things happen, and mankind does not bother about them.  It
requires a very unusual mind to undertake the analysis of the obvious.
-- Alfred N. Whitehead