GPS Usage
This is a surprise:
"in reality more than 90 percent of the users of GPS worldwide use it
primarily for a timing reference."
That makes the LORAN shutdown look even more idiotiuc!
-John
==============
Copied from http://www.gpsworld.com/defense/gps-insights-april-2007-8428:
"I recently...participate[d] in a...study that determined...that if GPS
were to fail today, there is an excellent chance that credit cards would
not function, gas pumps would not operate, cell phones would not work,
internet, bank and stock transactions would slow to a crawl, and on and
on.
"To fully understand this, remember that the Global Positioning System is
also known as a PNT or Positioning, Navigation and Timing system. The
position and navigation part is what we generally think of, but in reality
more than 90 percent of the users of GPS worldwide use it primarily for a
timing reference.
"This timing discussion provides a nice segue to the topic of LORAN and
eLORAN, which last month I listed as a key augmentation for the perfect
handheld GPS transceiver. Several of you asked why and there are a myriad
of reasons including: LORAN is a mature and proven system with much
greater signal strength (you can use it indoors)....
"Why do we need a backup? Here is a classic case in point..... [I]t took
NAVCEN and supporting agencies 72 hours to pinpoint the jamming
source...."
=======
In message 55371.12.6.201.2.1299648580.squirrel@popaccts.quikus.com, "J. Fors
ter" writes:
"in reality more than 90 percent of the users of GPS worldwide use it
primarily for a timing reference."
That makes the LORAN shutdown look even more idiotiuc!
Well, how can you argue with closing a system that was aiding terrorists ?
The reason LORAN-C got killed was that DoD/DHS couldn't jam it if a
terrorist with a suitcase-nuke was trying to find his way to Congress.
Your government money at work...
--
Poul-Henning Kamp | UNIX since Zilog Zeus 3.20
phk@FreeBSD.ORG | TCP/IP since RFC 956
FreeBSD committer | BSD since 4.3-tahoe
Never attribute to malice what can adequately be explained by incompetence.
El 09/03/2011 06:29, J. Forster escribió:
This is a surprise:
"in reality more than 90 percent of the users of GPS worldwide use it
primarily for a timing reference."
This is a phallacy, except if we are taking into account indirect GPS
users, i.e. admitting that a credit card user is a GPS user because the
timestamping of the translation relies on a GPS :) But I suspect that,
except in our time-nuts laboratories, the percentage of GPS receivers
dedicated to timing compared to those dedicated to positioning is really
low. Also, sometimes GPS timing is used because it is unexpensive, but
provides an accuracy orders of magnitude better than the real needs (a
traffic control radar camera tags the pictures with a one second
precision... but uses a GPS, could be tagged with microsecond precission
;) ).
And anyway, in a no-GPS world with real mass high-precission timing
needs, other methods could be used... that would suppose a higher demand
of Cs clocks and H-masers (so we could buy a good user H-maser for
USD100 at the place you all know? mmm... not so bad ;) )
--
Javier Herrero EMAIL: jherrero@hvsistemas.com
Chief Technology Officer
HV Sistemas S.L. PHONE: +34 949 336 806
Los Charcones, 17 FAX: +34 949 336 792
19170 El Casar - Guadalajara - Spain WEB: http://www.hvsistemas.com
In message 4D7740B8.2040307@hvsistemas.es, Javier Herrero writes:
El 09/03/2011 06:29, J. Forster escribi=F3:
This is a surprise:
"in reality more than 90 percent of the users of GPS worldwide use it
primarily for a timing reference."
This is a phallacy, except if we are taking into account indirect GPS
users,
By far the biggest one is cell-phone base stations, and since these
don't work without good timesync (See recent story about the Koreas)
I think it is fair to include the "indirect users" in the collateral
damage.
--
Poul-Henning Kamp | UNIX since Zilog Zeus 3.20
phk@FreeBSD.ORG | TCP/IP since RFC 956
FreeBSD committer | BSD since 4.3-tahoe
Never attribute to malice what can adequately be explained by incompetence.
By far the biggest one is cell-phone base stations, and since these
don't work without good timesync (See recent story about the Koreas)
I think it is fair to include the "indirect users" in the collateral
damage.
Yes... most collateral damages are ever inflinged to indirect users :)
Regards,
Javier
--
Javier Herrero EMAIL: jherrero@hvsistemas.com
Chief Technology Officer
HV Sistemas S.L. PHONE: +34 949 336 806
Los Charcones, 17 FAX: +34 949 336 792
19170 El Casar - Guadalajara - Spain WEB: http://www.hvsistemas.com
OK really getting off topic
Soooo without GPS timing Celphones would not work. How is this a bad thing?
That means the people talking and texting while driving, might actually stay
in their lanes.
Sounding pretty good to me.
We did not shut down Loran for some crazy plot. We did it to save the budget
and the world. That $36M was just killing the Obama administration.
With LORAN off we are greening the world, saving birds, improving the
economy and creating 1000s of new jobs. (I don't know about the last comment
but all of our politicians finish off every sentence with that comment).
Regard
Paul
On Wed, Mar 9, 2011 at 4:37 AM, Javier Herrero jherrero@hvsistemas.eswrote:
By far the biggest one is cell-phone base stations, and since these
don't work without good timesync (See recent story about the Koreas)
I think it is fair to include the "indirect users" in the collateral
damage.
Yes... most collateral damages are ever inflinged to indirect users :)
Regards,
Javier
--
Javier Herrero EMAIL: jherrero@hvsistemas.com
Chief Technology Officer
HV Sistemas S.L. PHONE: +34 949 336 806
Los Charcones, 17 FAX: +34 949 336 792
19170 El Casar - Guadalajara - Spain WEB: http://www.hvsistemas.com
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to
https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.
FWIW, I work at a University and we use NTP based time as the public
key for routing updates between our routers.
Back in 1989 or so one of our students got the bright idea to write a
program to capture routing updates, adjust the values and put the
packet(s) back on the wire... It took thirty minutes to understand the
problem and two hours to implement the crypto features across the
enterprise...
We have two GPS based timing devices plus we sync to other
sources over the Internet.
We have had one timing based issue over the years related to a
software failure in a GPS based unit which required a software update to
correct.
SSH, SSL and other things used for e-commerce do have timing sensitivities.
Jim Cotton
On 3/9/11 9:11 AM, paul swed wrote:
OK really getting off topic
Soooo without GPS timing Celphones would not work. How is this a bad thing?
That means the people talking and texting while driving, might actually stay
in their lanes.
Sounding pretty good to me.
We did not shut down Loran for some crazy plot. We did it to save the budget
and the world. That $36M was just killing the Obama administration.
With LORAN off we are greening the world, saving birds, improving the
economy and creating 1000s of new jobs. (I don't know about the last comment
but all of our politicians finish off every sentence with that comment).
Regard
Paul
On Wed, Mar 9, 2011 at 4:37 AM, Javier Herrerojherrero@hvsistemas.eswrote:
By far the biggest one is cell-phone base stations, and since these
don't work without good timesync (See recent story about the Koreas)
I think it is fair to include the "indirect users" in the collateral
damage.
Yes... most collateral damages are ever inflinged to indirect users :)
Regards,
Javier
--
Javier Herrero EMAIL: jherrero@hvsistemas.com
Chief Technology Officer
HV Sistemas S.L. PHONE: +34 949 336 806
Los Charcones, 17 FAX: +34 949 336 792
19170 El Casar - Guadalajara - Spain WEB: http://www.hvsistemas.com
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to
https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.
Lots of people use GPS for timing because it's cheaper or more
convenient in a budgetary sens than alternate approaches. Here at JPL,
it's easier, in general, for me to put a GPS timing receiver and GPSDO
in a lab than it is to try and run cables from the "house sources".
The latter requires involvement of more facilities folks and "touching"
more organizations (e.g. the people who "send" the signal, the people
who "maintain" the wires or fiber, etc.), many of whom will have some
sort of continuing charge (which is reasonable.. they ARE providing a
service), for which you need a valid charge number.
Putting a GPSDO in a lab requires a one-time purchase and a one time
facility request to put the antenna in.
We did a bit of an informal trade a few years back to look at 4
alternatives for a half dozen labs in our building.
- Distribute frequency standard and derived time code from JPL
Frequency/Timing Lab (the "maser") - Install a single GPSDO, and distribute the frequency reference and
timecode - Install a single antenna, splitter, and install a separate GPSDO in
each lab - Install multiple antennas and GPSDOs, one set for each lab.
the latter is the most flexible, and has the smallest "individual
increment" cost (i.e. there's no "capital improvement" going on)
Given the plethora of GPS antennas sprouting from the tops of buildings
around here, I suspect others have made similar analyses.
On Wed, Mar 09, 2011 at 08:01:31AM +0000, Poul-Henning Kamp wrote:
Well, how can you argue with closing a system that was aiding terrorists ?
The reason LORAN-C got killed was that DoD/DHS couldn't jam it if a
terrorist with a suitcase-nuke was trying to find his way to Congress.
Is this tongue in cheek, or do you have any actual basis
for stating that DHS was afraid Loran C WASN'T jammable ?
If the later, this is a rather provocative concept... make an
increasingly vital but easily jammed resource the only readily available
means of precision position and time determination so the government (or
some government, or for that matter many private malefactors) can be
sure to be able to reliably deny accurate position and or time to the
public (or at least many targeted groups within the public) at will ?
I wonder what the threat analysis behind this one was... making
an increasingly vital service more fragile because of what some have
called "movie thriller" plots ?
Have they really convinced themselves that bad guys CANNOT
figure out a workaround ? It has always happened in the past...
Your government money at work...
--
Dave Emery N1PRE/AE, die@dieconsulting.com DIE Consulting, Weston, Mass 02493
"An empty zombie mind with a forlorn barely readable weatherbeaten
'For Rent' sign still vainly flapping outside on the weed encrusted pole - in
celebration of what could have been, but wasn't and is not to be now either."
A good thing every air force base doesn't have a homing beacon. Oh wait,
never mind.
On 3/9/2011 10:54 PM, David I. Emery wrote:
On Wed, Mar 09, 2011 at 08:01:31AM +0000, Poul-Henning Kamp wrote:
Well, how can you argue with closing a system that was aiding terrorists ?