Discussion:
Lost GPS lock or 1PPS recently?
Add Reply
John Sloan
2018-09-04 16:31:54 UTC
Reply
Permalink
Raw Message
Folks:

GPS jamming and spoofing isn't really my area of expertise, but it's something I worry about, not just for its impact on geolocation and navigation applications, but also because GPS has become critical as a high precision timing reference in the telecommunications realm, which *is* my area of expertise.

Yesterday (2018-09-03) afternoon (about 22:00UTC, 16:00MDT) I noticed one of my three home-made GPS-disciplined NTP servers had lost its GPS lock. After some forensics on my part, this (2018-09-04) morning (about 16:00UTC, 10:00MDT) I replaced the amplified antenna, and the device reacquired its lock. I figured it was just an antenna failures; this is an amplified filtered antenna so it has active electronics.

Then just an hour or so later, I noticed one of my commercial GPS-disciplined NTP servers (TimeMachines) had lost the GPS 1PPS timing signal, but indicated it still had GPS lock. (I question now what this actually means in the context of this particular device). As a troubleshooting step, I power cycled the device, and it reacquired 1PPS. But as I did that, the second commercial GPS-disciplined NTP server (Uputronics) right next to it lit up with a red warning on its display, indicating it had lost GPS lock. A minute or so later it also reacquired lock and indicated 1PPS, with no action on my part.

All of these devices are completely independent, have different software (and probably hardware), have separate amplified antennas sitting side by side in the window of my home office, and are not all on the same electrical outlet (but may be on the same household circuit).

I lit up the LCD display on my little GPS monitoring tool I built that runs Lady Heather 24x7 and see on the graphical display sudden jumps of reduced timing accuracy of a factor of 10^2 (from nanoseconds to hundreds of nanoseconds) in the recent past. But I’m thinking this can also be caused just by the dynamic satellite geometry, and might be normal. It’s not like I watch this graph all the time (even though it does sit right in front of me on my desk).

No clue what's going on in my suburb near Golden Colorado. But I’m a little freaked out. Trying to figure out which rule, [1] It’s something stupid I’ve done, or [2] I am not unique, to apply.

:John

--
J. L. Sloan Digital Aggregates Corp.
+1 303 940 9064 (O) 3440 Youngfield St. #209
+1 303 489 5178 (M) Wheat Ridge CO 80033 USA
***@diag.com http://www.diag.com <http://www.diag.com/>
_______________________________________________
time-nuts mailing list -- time-***@lists.febo.com
To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.
Scott McGrath
2018-09-04 18:09:43 UTC
Reply
Permalink
Raw Message
My TrueTime DC-XL has lost lock since yesterday as has my Z3805 and my car’s onboard GPS will not lock since the 2’nd. I need to get about a mile from home before Car’s nav system reports ready.

There has been a great deal of repair work on the local cable system so this is almost certainly related to that

But it proves my point about the fragility of GPS
Dana Whitlow
2018-09-04 19:18:04 UTC
Reply
Permalink
Raw Message
Scott & John,

Do either of you have any activity by "Light Squared" (or whatever it's now
called) in your area. Jamming does not always have to be in-band to be
effective.

Dana
Post by Scott McGrath
My TrueTime DC-XL has lost lock since yesterday as has my Z3805 and my
car’s onboard GPS will not lock since the 2’nd. I need to get about a mile
from home before Car’s nav system reports ready.
There has been a great deal of repair work on the local cable system so
this is almost certainly related to that
But it proves my point about the fragility of GPS
GPS jamming and spoofing isn't really my area of expertise, but it's
something I worry about, not just for its impact on geolocation and
navigation applications, but also because GPS has become critical as a high
precision timing reference in the telecommunications realm, which *is* my
area of expertise.
Yesterday (2018-09-03) afternoon (about 22:00UTC, 16:00MDT) I noticed one
of my three home-made GPS-disciplined NTP servers had lost its GPS lock.
After some forensics on my part, this (2018-09-04) morning (about 16:00UTC,
10:00MDT) I replaced the amplified antenna, and the device reacquired its
lock. I figured it was just an antenna failures; this is an amplified
filtered antenna so it has active electronics.
Then just an hour or so later, I noticed one of my commercial
GPS-disciplined NTP servers (TimeMachines) had lost the GPS 1PPS timing
signal, but indicated it still had GPS lock. (I question now what this
actually means in the context of this particular device). As a
troubleshooting step, I power cycled the device, and it reacquired 1PPS.
But as I did that, the second commercial GPS-disciplined NTP server
(Uputronics) right next to it lit up with a red warning on its display,
indicating it had lost GPS lock. A minute or so later it also reacquired
lock and indicated 1PPS, with no action on my part.
All of these devices are completely independent, have different software
(and probably hardware), have separate amplified antennas sitting side by
side in the window of my home office, and are not all on the same
electrical outlet (but may be on the same household circuit).
I lit up the LCD display on my little GPS monitoring tool I built that
runs Lady Heather 24x7 and see on the graphical display sudden jumps of
reduced timing accuracy of a factor of 10^2 (from nanoseconds to hundreds
of nanoseconds) in the recent past. But I’m thinking this can also be
caused just by the dynamic satellite geometry, and might be normal. It’s
not like I watch this graph all the time (even though it does sit right in
front of me on my desk).
No clue what's going on in my suburb near Golden Colorado. But I’m a
little freaked out. Trying to figure out which rule, [1] It’s something
stupid I’ve done, or [2] I am not unique, to apply.
:John
--
J. L. Sloan Digital Aggregates Corp.
+1 303 940 9064 (O) 3440 Youngfield St. #209
+1 303 489 5178 (M) Wheat Ridge CO 80033 USA
_______________________________________________
To unsubscribe, go to
http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
and follow the instructions there.
_______________________________________________
To unsubscribe, go to
http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
and follow the instructions there.
_______________________________________________
time-nuts mailing list -- time-***@lists.febo.com
To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-n
Scott McGrath
2018-09-04 20:49:37 UTC
Reply
Permalink
Raw Message
Actually. I have 6... And a large assortment of directional antennas of many flavors LPDA, Horn etc, I have to get out there and find the interfering source.

Cable company has been having problems with ‘booster’ amplifiers installed by homeowners to ‘clean up’ noisy DTV signals. So just imagine a cheap unshielded amp driven into clipping.

I live in the sticks so LightSquared or its successor is unlikely to be the source in my case.



On Sep 4, 2018, at 3:18 PM, Dana Whitlow <***@gmail.com> wrote:

Scott & John,

Do either of you have any activity by "Light Squared" (or whatever it's now
called) in your area. Jamming does not always have to be in-band to be
effective.

Dana
Post by Scott McGrath
My TrueTime DC-XL has lost lock since yesterday as has my Z3805 and my
car’s onboard GPS will not lock since the 2’nd. I need to get about a mile
from home before Car’s nav system reports ready.
There has been a great deal of repair work on the local cable system so
this is almost certainly related to that
But it proves my point about the fragility of GPS
GPS jamming and spoofing isn't really my area of expertise, but it's
something I worry about, not just for its impact on geolocation and
navigation applications, but also because GPS has become critical as a high
precision timing reference in the telecommunications realm, which *is* my
area of expertise.
Yesterday (2018-09-03) afternoon (about 22:00UTC, 16:00MDT) I noticed one
of my three home-made GPS-disciplined NTP servers had lost its GPS lock.
After some forensics on my part, this (2018-09-04) morning (about 16:00UTC,
10:00MDT) I replaced the amplified antenna, and the device reacquired its
lock. I figured it was just an antenna failures; this is an amplified
filtered antenna so it has active electronics.
Then just an hour or so later, I noticed one of my commercial
GPS-disciplined NTP servers (TimeMachines) had lost the GPS 1PPS timing
signal, but indicated it still had GPS lock. (I question now what this
actually means in the context of this particular device). As a
troubleshooting step, I power cycled the device, and it reacquired 1PPS.
But as I did that, the second commercial GPS-disciplined NTP server
(Uputronics) right next to it lit up with a red warning on its display,
indicating it had lost GPS lock. A minute or so later it also reacquired
lock and indicated 1PPS, with no action on my part.
All of these devices are completely independent, have different software
(and probably hardware), have separate amplified antennas sitting side by
side in the window of my home office, and are not all on the same
electrical outlet (but may be on the same household circuit).
I lit up the LCD display on my little GPS monitoring tool I built that
runs Lady Heather 24x7 and see on the graphical display sudden jumps of
reduced timing accuracy of a factor of 10^2 (from nanoseconds to hundreds
of nanoseconds) in the recent past. But I’m thinking this can also be
caused just by the dynamic satellite geometry, and might be normal. It’s
not like I watch this graph all the time (even though it does sit right in
front of me on my desk).
No clue what's going on in my suburb near Golden Colorado. But I’m a
little freaked out. Trying to figure out which rule, [1] It’s something
stupid I’ve done, or [2] I am not unique, to apply.
:John
--
J. L. Sloan Digital Aggregates Corp.
+1 303 940 9064 (O) 3440 Youngfield St. #209
+1 303 489 5178 (M) Wheat Ridge CO 80033 USA
_______________________________________________
To unsubscribe, go to
http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
and follow the instructions there.
_______________________________________________
To unsubscribe, go to
http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
and follow the instructions there.
_______________________________________________
time-nuts mailing list -- time-***@lists.febo.com
To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
and follow the instructions there.

_______________________________________________
time-nuts mailing list -- time-***@lists.febo.com
To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
and fol
Scott McGrath
2018-09-04 21:09:36 UTC
Reply
Permalink
Raw Message
Thanks for the NOTAMS, Do a bit of flying as well but i’m northern NE and this particular outage is bounded by a rocky valley so I suspect ground based interference to be the culprit.

The great irony here is i have a Tek RSA306A with the interference package which uses wait for it ...GPS... to ensure an accurate reading and to plot locations on a map. Get multiple bearings on a source compare the signal and you have your culprit in the bag.

But no GPS... makes package less convenient back to street corners and ordinance maps to get grid coordinates



On Sep 4, 2018, at 4:49 PM, Scott McGrath <***@gmail.com> wrote:

Actually. I have 6... And a large assortment of directional antennas of many flavors LPDA, Horn etc, I have to get out there and find the interfering source.

Cable company has been having problems with ‘booster’ amplifiers installed by homeowners to ‘clean up’ noisy DTV signals. So just imagine a cheap unshielded amp driven into clipping.

I live in the sticks so LightSquared or its successor is unlikely to be the source in my case.



On Sep 4, 2018, at 3:18 PM, Dana Whitlow <***@gmail.com> wrote:

Scott & John,

Do either of you have any activity by "Light Squared" (or whatever it's now
called) in your area. Jamming does not always have to be in-band to be
effective.

Dana
Post by Scott McGrath
My TrueTime DC-XL has lost lock since yesterday as has my Z3805 and my
car’s onboard GPS will not lock since the 2’nd. I need to get about a mile
from home before Car’s nav system reports ready.
There has been a great deal of repair work on the local cable system so
this is almost certainly related to that
But it proves my point about the fragility of GPS
GPS jamming and spoofing isn't really my area of expertise, but it's
something I worry about, not just for its impact on geolocation and
navigation applications, but also because GPS has become critical as a high
precision timing reference in the telecommunications realm, which *is* my
area of expertise.
Yesterday (2018-09-03) afternoon (about 22:00UTC, 16:00MDT) I noticed one
of my three home-made GPS-disciplined NTP servers had lost its GPS lock.
After some forensics on my part, this (2018-09-04) morning (about 16:00UTC,
10:00MDT) I replaced the amplified antenna, and the device reacquired its
lock. I figured it was just an antenna failures; this is an amplified
filtered antenna so it has active electronics.
Then just an hour or so later, I noticed one of my commercial
GPS-disciplined NTP servers (TimeMachines) had lost the GPS 1PPS timing
signal, but indicated it still had GPS lock. (I question now what this
actually means in the context of this particular device). As a
troubleshooting step, I power cycled the device, and it reacquired 1PPS.
But as I did that, the second commercial GPS-disciplined NTP server
(Uputronics) right next to it lit up with a red warning on its display,
indicating it had lost GPS lock. A minute or so later it also reacquired
lock and indicated 1PPS, with no action on my part.
All of these devices are completely independent, have different software
(and probably hardware), have separate amplified antennas sitting side by
side in the window of my home office, and are not all on the same
electrical outlet (but may be on the same household circuit).
I lit up the LCD display on my little GPS monitoring tool I built that
runs Lady Heather 24x7 and see on the graphical display sudden jumps of
reduced timing accuracy of a factor of 10^2 (from nanoseconds to hundreds
of nanoseconds) in the recent past. But I’m thinking this can also be
caused just by the dynamic satellite geometry, and might be normal. It’s
not like I watch this graph all the time (even though it does sit right in
front of me on my desk).
No clue what's going on in my suburb near Golden Colorado. But I’m a
little freaked out. Trying to figure out which rule, [1] It’s something
stupid I’ve done, or [2] I am not unique, to apply.
:John
--
J. L. Sloan Digital Aggregates Corp.
+1 303 940 9064 (O) 3440 Youngfield St. #209
+1 303 489 5178 (M) Wheat Ridge CO 80033 USA
_______________________________________________
To unsubscribe, go to
http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
and follow the instructions there.
_______________________________________________
To unsubscribe, go to
http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
and follow the instructions there.
_______________________________________________
time-nuts mailing list -- time-***@lists.febo.com
To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
and follow the instructions there.

_______________________________________________
time-nuts mailing list -- time-***@lists.febo.com
To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.f
Graham / KE9H
2018-09-04 19:21:35 UTC
Reply
Permalink
Raw Message
The following are active GPS NOTAMs.
Data Current as of: Tue, 04 Sep 2018 19:16:00 UTC
GPS GLOBAL POSITIONING SYSTEM [Back to Top] !GPS 09/009 (KNMH A0020/18)
GPS NAV PRN 02 OUT OF SERVICE 1809061455-1809070255

ZAB ALBUQUERQUE (ARTCC),NM. [Back to Top] !GPS 08/259 (KZAB A0367/18) ZAB
NAV GPS (WSMR GPS 18-20) (INCLUDING WAAS, GBAS, AND ADS-B) MAY NOT BE AVBL
WI A 359NM RADIUS CENTERED AT 333345N1063840W (TCS054036) FL400-UNL, 311NM
RADIUS AT FL250, 215NM RADIUS AT 10000FT, 223NM RADIUS AT 4000FT AGL, 169NM
RADIUS AT 50FT AGL DLY 1830-2230 1809031830-1809082230

ZDV DENVER (ARTCC),CO. [Back to Top] !GPS 08/260 (KZDV A0287/18) ZDV NAV
GPS (WSMR GPS 18-20) (INCLUDING WAAS, GBAS, AND ADS-B) MAY NOT BE AVBL WI A
359NM RADIUS CENTERED AT 333345N1063840W (TCS054036) FL400-UNL, 311NM
RADIUS AT FL250, 215NM RADIUS AT 10000FT, 223NM RADIUS AT 4000FT AGL, 169NM
RADIUS AT 50FT AGL DLY 1830-2230 1809031830-1809082230

The military does testing that can cause GPS jamming down in New Mexico.
Are you within range of these NOTAMS?
You might have to plot the Lat-Long co-ordinates

--- Graham

==
Post by Scott McGrath
My TrueTime DC-XL has lost lock since yesterday as has my Z3805 and my
car’s onboard GPS will not lock since the 2’nd. I need to get about a mile
from home before Car’s nav system reports ready.
There has been a great deal of repair work on the local cable system so
this is almost certainly related to that
But it proves my point about the fragility of GPS
GPS jamming and spoofing isn't really my area of expertise, but it's
something I worry about, not just for its impact on geolocation and
navigation applications, but also because GPS has become critical as a high
precision timing reference in the telecommunications realm, which *is* my
area of expertise.
Yesterday (2018-09-03) afternoon (about 22:00UTC, 16:00MDT) I noticed one
of my three home-made GPS-disciplined NTP servers had lost its GPS lock.
After some forensics on my part, this (2018-09-04) morning (about 16:00UTC,
10:00MDT) I replaced the amplified antenna, and the device reacquired its
lock. I figured it was just an antenna failures; this is an amplified
filtered antenna so it has active electronics.
Then just an hour or so later, I noticed one of my commercial
GPS-disciplined NTP servers (TimeMachines) had lost the GPS 1PPS timing
signal, but indicated it still had GPS lock. (I question now what this
actually means in the context of this particular device). As a
troubleshooting step, I power cycled the device, and it reacquired 1PPS.
But as I did that, the second commercial GPS-disciplined NTP server
(Uputronics) right next to it lit up with a red warning on its display,
indicating it had lost GPS lock. A minute or so later it also reacquired
lock and indicated 1PPS, with no action on my part.
All of these devices are completely independent, have different software
(and probably hardware), have separate amplified antennas sitting side by
side in the window of my home office, and are not all on the same
electrical outlet (but may be on the same household circuit).
I lit up the LCD display on my little GPS monitoring tool I built that
runs Lady Heather 24x7 and see on the graphical display sudden jumps of
reduced timing accuracy of a factor of 10^2 (from nanoseconds to hundreds
of nanoseconds) in the recent past. But I’m thinking this can also be
caused just by the dynamic satellite geometry, and might be normal. It’s
not like I watch this graph all the time (even though it does sit right in
front of me on my desk).
No clue what's going on in my suburb near Golden Colorado. But I’m a
little freaked out. Trying to figure out which rule, [1] It’s something
stupid I’ve done, or [2] I am not unique, to apply.
:John
--
J. L. Sloan Digital Aggregates Corp.
+1 303 940 9064 (O) 3440 Youngfield St. #209
+1 303 489 5178 (M) Wheat Ridge CO 80033 USA
_______________________________________________
To unsubscribe, go to
http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
and follow the instructions there.
_______________________________________________
To unsubscribe, go to
http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
and follow the instructions there.
_______________________________________________
time-nuts mailing list -- time-***@lists.febo.com
To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
and follow the instructions t
Peter Laws
2018-09-07 23:33:42 UTC
Reply
Permalink
Raw Message
Post by Graham / KE9H
The following are active GPS NOTAMs.
Didn't know NOTAMs went out for GPS interruptions but of course they
do. Surprised, actually, that there are so many. And yet, life goes
on. Must be all those WWV backups.

https://pilotweb.nas.faa.gov/PilotWeb/noticesAction.do?queryType=ALLGPS&formatType=ICAO
--
Peter Laws | N5UWY | plaws plaws net | Travel by Train!

_______________________________________________
time-nuts mailing list -- time-***@lists.febo.com
To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
and follow the instructions there.
John Sloan
2018-09-06 13:53:46 UTC
Reply
Permalink
Raw Message
Folks:

Well blow me down. It took some Google Maps fu on the web on my part, but
my time and place does indeed coincide with this “GPS Interference Testing” at
White Sands Missile Range. I just happened to be in my home office watching
several of my GPS-disciplined NTP servers when this occurred. Thanks, Graham!

:John
Post by Graham / KE9H
ZDV DENVER (ARTCC),CO. [Back to Top] !GPS 08/260 (KZDV A0287/18) ZDV NAV
GPS (WSMR GPS 18-20) (INCLUDING WAAS, GBAS, AND ADS-B) MAY NOT BE AVBL WI A
359NM RADIUS CENTERED AT 333345N1063840W (TCS054036) FL400-UNL, 311NM
RADIUS AT FL250, 215NM RADIUS AT 10000FT, 223NM RADIUS AT 4000FT AGL, 169NM
RADIUS AT 50FT AGL DLY 1830-2230 1809031830-1809082230
--
J. L. Sloan Digital Aggregates Corp.
+1 303 940 9064 (O) 3440 Youngfield St. #209
+1 303 489 5178 (M) Wheat Ridge CO 80033 USA
***@diag.com http://www.diag.com <http://www.diag.com/>


_______________________________________________
time-nuts mailing list -- time-***@lists.febo.com
To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.f
Scott McGrath
2018-09-06 15:34:32 UTC
Reply
Permalink
Raw Message
And there is the other significant vulnerability since GPS is a MILITARY system the DoD can take it offline for any reason at any time.

Leaving civilian users with nothing,

If its a national security threat its likely the other GNSS systems will be unavailable as well.





On Sep 6, 2018, at 9:53 AM, John Sloan <***@diag.com> wrote:


Folks:

Well blow me down. It took some Google Maps fu on the web on my part, but
my time and place does indeed coincide with this “GPS Interference Testing” at
White Sands Missile Range. I just happened to be in my home office watching
several of my GPS-disciplined NTP servers when this occurred. Thanks, Graham!

:John
Post by Graham / KE9H
ZDV DENVER (ARTCC),CO. [Back to Top] !GPS 08/260 (KZDV A0287/18) ZDV NAV
GPS (WSMR GPS 18-20) (INCLUDING WAAS, GBAS, AND ADS-B) MAY NOT BE AVBL WI A
359NM RADIUS CENTERED AT 333345N1063840W (TCS054036) FL400-UNL, 311NM
RADIUS AT FL250, 215NM RADIUS AT 10000FT, 223NM RADIUS AT 4000FT AGL, 169NM
RADIUS AT 50FT AGL DLY 1830-2230 1809031830-1809082230
--
J. L. Sloan Digital Aggregates Corp.
+1 303 940 9064 (O) 3440 Youngfield St. #209
+1 303 489 5178 (M) Wheat Ridge CO 80033 USA
***@diag.com http://www.diag.com <http://www.diag.com/>


_______________________________________________
time-nuts mailing list -- time-***@lists.febo.com
To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
and follow the instructions there.

_______________________________________________
time-nuts mailing list -- time-***@lists.febo.com
To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.fe
David Van Horn
2018-09-06 16:12:15 UTC
Reply
Permalink
Raw Message
We just put up another GPS antenna for our backup thunderbolt, and now IT is blaming that for why our wifi is sluggish.
And it happens whether the new antenna is even connected!

https://www.kb6nu.com/theyll-do-it-every-time/


I should have known.. (KC6ETE here)
_______________________________________________
time-nuts mailing list -- time-***@lists.febo.com
To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
and follow the instructions there.
Bob kb8tq
2018-09-06 20:56:40 UTC
Reply
Permalink
Raw Message
Hi

Well, we *do* have experience with that. It was called selective availability. Indeed it might get turned back on again. It’s impact on a properly designed GPSDO - not much. It takes a bit longer to get to best stability. System time wise, it still works “good enough”.

A four hour long test format also does basically nothing to a GPSDO based system. You didn’t read anything in the papers about all cell service in three states going away. The devices did what they are supposed to do and everything did it’s boringly normal thing ….. it worked fine.

I still don’t quite understand just what people think could replace satellite based timing in these systems. None of the “radio based” systems are within a factor many thousands to a few million of being adequate.

=====

Now, if this is headed off into a “the government is coming to break down the doors and take away all my toys sort of thing. That’s very much *not* a Time Nuts topic.

Bob
Post by Scott McGrath
And there is the other significant vulnerability since GPS is a MILITARY system the DoD can take it offline for any reason at any time.
Leaving civilian users with nothing,
If its a national security threat its likely the other GNSS systems will be unavailable as well.
Well blow me down. It took some Google Maps fu on the web on my part, but
my time and place does indeed coincide with this “GPS Interference Testing” at
White Sands Missile Range. I just happened to be in my home office watching
several of my GPS-disciplined NTP servers when this occurred. Thanks, Graham!
:John
Post by Graham / KE9H
ZDV DENVER (ARTCC),CO. [Back to Top] !GPS 08/260 (KZDV A0287/18) ZDV NAV
GPS (WSMR GPS 18-20) (INCLUDING WAAS, GBAS, AND ADS-B) MAY NOT BE AVBL WI A
359NM RADIUS CENTERED AT 333345N1063840W (TCS054036) FL400-UNL, 311NM
RADIUS AT FL250, 215NM RADIUS AT 10000FT, 223NM RADIUS AT 4000FT AGL, 169NM
RADIUS AT 50FT AGL DLY 1830-2230 1809031830-1809082230
--
J. L. Sloan Digital Aggregates Corp.
+1 303 940 9064 (O) 3440 Youngfield St. #209
+1 303 489 5178 (M) Wheat Ridge CO 80033 USA
_______________________________________________
To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
and follow the instructions there.
_______________________________________________
To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
and follow the instructions there.
_______________________________________________
time-nuts mailing list -- time-***@lists.febo.com
To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
an
Scott McGrath
2018-09-06 22:35:23 UTC
Reply
Permalink
Raw Message
Actually we DID have a radio based system that provided sufficient accuracy it was called eLORAN but it was killed by US politicians because they did not want a much more inexpensive to operate system ‘competing’ with GPS. Shutting down LORAN saved 32m dollars annually the NAVSTAR GPS program costs billions annually.

Ironically while LORAN’s absolute accuracy is less than GPS, repeatability was much better so fishermen liked LORAN better.

Once again the empty suits won and the navigation and timing community lost.

Wrt cellsites staying operational i imagine the oscillators in holdover would probably remain sufficiently synchronized for a month or so.



On Sep 6, 2018, at 4:56 PM, Bob kb8tq <***@n1k.org> wrote:

Hi

Well, we *do* have experience with that. It was called selective availability. Indeed it might get turned back on again. It’s impact on a properly designed GPSDO - not much. It takes a bit longer to get to best stability. System time wise, it still works “good enough”.

A four hour long test format also does basically nothing to a GPSDO based system. You didn’t read anything in the papers about all cell service in three states going away. The devices did what they are supposed to do and everything did it’s boringly normal thing ….. it worked fine.

I still don’t quite understand just what people think could replace satellite based timing in these systems. None of the “radio based” systems are within a factor many thousands to a few million of being adequate.

=====

Now, if this is headed off into a “the government is coming to break down the doors and take away all my toys sort of thing. That’s very much *not* a Time Nuts topic.

Bob
Post by Scott McGrath
And there is the other significant vulnerability since GPS is a MILITARY system the DoD can take it offline for any reason at any time.
Leaving civilian users with nothing,
If its a national security threat its likely the other GNSS systems will be unavailable as well.
Well blow me down. It took some Google Maps fu on the web on my part, but
my time and place does indeed coincide with this “GPS Interference Testing” at
White Sands Missile Range. I just happened to be in my home office watching
several of my GPS-disciplined NTP servers when this occurred. Thanks, Graham!
:John
Post by Graham / KE9H
ZDV DENVER (ARTCC),CO. [Back to Top] !GPS 08/260 (KZDV A0287/18) ZDV NAV
GPS (WSMR GPS 18-20) (INCLUDING WAAS, GBAS, AND ADS-B) MAY NOT BE AVBL WI A
359NM RADIUS CENTERED AT 333345N1063840W (TCS054036) FL400-UNL, 311NM
RADIUS AT FL250, 215NM RADIUS AT 10000FT, 223NM RADIUS AT 4000FT AGL, 169NM
RADIUS AT 50FT AGL DLY 1830-2230 1809031830-1809082230
--
J. L. Sloan Digital Aggregates Corp.
+1 303 940 9064 (O) 3440 Youngfield St. #209
+1 303 489 5178 (M) Wheat Ridge CO 80033 USA
_______________________________________________
To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
and follow the instructions there.
_______________________________________________
To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
and follow the instructions there.
_______________________________________________
time-nuts mailing list -- time-***@lists.febo.com
To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
and follow the instructions there.

_______________________________________________
time-nuts mailing list -- time-***@lists.febo.com
To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
and follow the
David I. Emery
2018-09-06 23:26:06 UTC
Reply
Permalink
Raw Message
Actually we DID have a radio based system that provided sufficient accuracy it was called eLORAN but it was killed by US politicians because they did not want a much more inexpensive to operate system ???competing??? with GPS. Shutting down LORAN saved 32m dollars annually the NAVSTAR GPS program costs billions annually.
Once again the empty suits won and the navigation and timing community lost.
FWLIW, my brother in law was the USCG admiral who was CFO (and
chief bean counter) of the USCG when that was going down. I tried, but
ran into the "it's classified" stuff... I think they had a rationale
other than just cost. There is an argument that denying GPS to
terrorists in crisis situations is much easier than denying E-Loran...

He is not an empty suit BTW, though a helo pilot (and MBA) by
training and not a time nut or engineer. Now long out of the USCG and
executive VP of a Cruise line.
--
Dave Emery N1PRE/AE, ***@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."


_______________________________________________
time-nuts mailing list -- time-***@lists.febo.com
To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
and follow the instructions there.
Bob Martin
2018-09-06 23:01:22 UTC
Reply
Permalink
Raw Message
I'm sure this has been discussed many times here.

E-Loran - I designed the timing hardware that controlled the
transmitters for that upgrade while I was at Timing Solutions.

As I remember it, it was funded by the FAA to be a backup for GPS.
The FAA planned to make more use of GPS in the future (distant
future given the speed at which the FAA moves).

I'm not sure the Coast Guard was excited about the responsibility
of running LORAN.

Here is a powerpoint presentation arguing for e-loran:

https://www.gps.gov/governance/advisory/meetings/2009-05/doherty.pdf

Bob Martin
Post by Scott McGrath
Actually we DID have a radio based system that provided sufficient accuracy it was called eLORAN but it was killed by US politicians because they did not want a much more inexpensive to operate system ‘competing’ with GPS. Shutting down LORAN saved 32m dollars annually the NAVSTAR GPS program costs billions annually.
Ironically while LORAN’s absolute accuracy is less than GPS, repeatability was much better so fishermen liked LORAN better.
Once again the empty suits won and the navigation and timing community lost.
Wrt cellsites staying operational i imagine the oscillators in holdover would probably remain sufficiently synchronized for a month or so.
Hi
Well, we *do* have experience with that. It was called selective availability. Indeed it might get turned back on again. It’s impact on a properly designed GPSDO - not much. It takes a bit longer to get to best stability. System time wise, it still works “good enough”.
A four hour long test format also does basically nothing to a GPSDO based system. You didn’t read anything in the papers about all cell service in three states going away. The devices did what they are supposed to do and everything did it’s boringly normal thing ….. it worked fine.
I still don’t quite understand just what people think could replace satellite based timing in these systems. None of the “radio based” systems are within a factor many thousands to a few million of being adequate.
=====
Now, if this is headed off into a “the government is coming to break down the doors and take away all my toys sort of thing. That’s very much *not* a Time Nuts topic.
Bob
Post by Scott McGrath
And there is the other significant vulnerability since GPS is a MILITARY system the DoD can take it offline for any reason at any time.
Leaving civilian users with nothing,
If its a national security threat its likely the other GNSS systems will be unavailable as well.
Well blow me down. It took some Google Maps fu on the web on my part, but
my time and place does indeed coincide with this “GPS Interference Testing” at
White Sands Missile Range. I just happened to be in my home office watching
several of my GPS-disciplined NTP servers when this occurred. Thanks, Graham!
:John
Post by Graham / KE9H
ZDV DENVER (ARTCC),CO. [Back to Top] !GPS 08/260 (KZDV A0287/18) ZDV NAV
GPS (WSMR GPS 18-20) (INCLUDING WAAS, GBAS, AND ADS-B) MAY NOT BE AVBL WI A
359NM RADIUS CENTERED AT 333345N1063840W (TCS054036) FL400-UNL, 311NM
RADIUS AT FL250, 215NM RADIUS AT 10000FT, 223NM RADIUS AT 4000FT AGL, 169NM
RADIUS AT 50FT AGL DLY 1830-2230 1809031830-1809082230
--
J. L. Sloan Digital Aggregates Corp.
+1 303 940 9064 (O) 3440 Youngfield St. #209
+1 303 489 5178 (M) Wheat Ridge CO 80033 USA
_______________________________________________
To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
and follow the instructions there.
_______________________________________________
To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
and follow the instructions there.
_______________________________________________
To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
and follow the instructions there.
_______________________________________________
To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
and follow the instructions there.
_______________________________________________
time-nuts mailing list -- time-***@lists.febo.com
To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nu
Bob kb8tq
2018-09-07 00:04:52 UTC
Reply
Permalink
Raw Message
Hi

No, eLoran *never* on it’s best day could ever deliver the kind of timing that the vast majority
of these systems require. It simply is not and can not do the job. The world has moved *way*
past the sort of timing it can actually deliver.

Bob
Post by Scott McGrath
Actually we DID have a radio based system that provided sufficient accuracy it was called eLORAN but it was killed by US politicians because they did not want a much more inexpensive to operate system ‘competing’ with GPS. Shutting down LORAN saved 32m dollars annually the NAVSTAR GPS program costs billions annually.
Ironically while LORAN’s absolute accuracy is less than GPS, repeatability was much better so fishermen liked LORAN better.
Once again the empty suits won and the navigation and timing community lost.
Wrt cellsites staying operational i imagine the oscillators in holdover would probably remain sufficiently synchronized for a month or so.
Hi
Well, we *do* have experience with that. It was called selective availability. Indeed it might get turned back on again. It’s impact on a properly designed GPSDO - not much. It takes a bit longer to get to best stability. System time wise, it still works “good enough”.
A four hour long test format also does basically nothing to a GPSDO based system. You didn’t read anything in the papers about all cell service in three states going away. The devices did what they are supposed to do and everything did it’s boringly normal thing ….. it worked fine.
I still don’t quite understand just what people think could replace satellite based timing in these systems. None of the “radio based” systems are within a factor many thousands to a few million of being adequate.
=====
Now, if this is headed off into a “the government is coming to break down the doors and take away all my toys sort of thing. That’s very much *not* a Time Nuts topic.
Bob
Post by Scott McGrath
And there is the other significant vulnerability since GPS is a MILITARY system the DoD can take it offline for any reason at any time.
Leaving civilian users with nothing,
If its a national security threat its likely the other GNSS systems will be unavailable as well.
Well blow me down. It took some Google Maps fu on the web on my part, but
my time and place does indeed coincide with this “GPS Interference Testing” at
White Sands Missile Range. I just happened to be in my home office watching
several of my GPS-disciplined NTP servers when this occurred. Thanks, Graham!
:John
Post by Graham / KE9H
ZDV DENVER (ARTCC),CO. [Back to Top] !GPS 08/260 (KZDV A0287/18) ZDV NAV
GPS (WSMR GPS 18-20) (INCLUDING WAAS, GBAS, AND ADS-B) MAY NOT BE AVBL WI A
359NM RADIUS CENTERED AT 333345N1063840W (TCS054036) FL400-UNL, 311NM
RADIUS AT FL250, 215NM RADIUS AT 10000FT, 223NM RADIUS AT 4000FT AGL, 169NM
RADIUS AT 50FT AGL DLY 1830-2230 1809031830-1809082230
--
J. L. Sloan Digital Aggregates Corp.
+1 303 940 9064 (O) 3440 Youngfield St. #209
+1 303 489 5178 (M) Wheat Ridge CO 80033 USA
_______________________________________________
To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
and follow the instructions there.
_______________________________________________
To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
and follow the instructions there.
_______________________________________________
To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
and follow the instructions there.
_______________________________________________
To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
and follow the instructions there.
_______________________________________________
time-nuts mailing list -- time-***@lists.febo.com
To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
and follow the instructions
Scott McGrath
2018-09-07 00:44:49 UTC
Reply
Permalink
Raw Message
Gee, thats strange especially for those of us who ran the Austron comparitors to check our local standards against the LORSTA’s



On Sep 6, 2018, at 8:04 PM, Bob kb8tq <***@n1k.org> wrote:

Hi

No, eLoran *never* on it’s best day could ever deliver the kind of timing that the vast majority
of these systems require. It simply is not and can not do the job. The world has moved *way*
past the sort of timing it can actually deliver.

Bob
Post by Scott McGrath
Actually we DID have a radio based system that provided sufficient accuracy it was called eLORAN but it was killed by US politicians because they did not want a much more inexpensive to operate system ‘competing’ with GPS. Shutting down LORAN saved 32m dollars annually the NAVSTAR GPS program costs billions annually.
Ironically while LORAN’s absolute accuracy is less than GPS, repeatability was much better so fishermen liked LORAN better.
Once again the empty suits won and the navigation and timing community lost.
Wrt cellsites staying operational i imagine the oscillators in holdover would probably remain sufficiently synchronized for a month or so.
Hi
Well, we *do* have experience with that. It was called selective availability. Indeed it might get turned back on again. It’s impact on a properly designed GPSDO - not much. It takes a bit longer to get to best stability. System time wise, it still works “good enough”.
A four hour long test format also does basically nothing to a GPSDO based system. You didn’t read anything in the papers about all cell service in three states going away. The devices did what they are supposed to do and everything did it’s boringly normal thing ….. it worked fine.
I still don’t quite understand just what people think could replace satellite based timing in these systems. None of the “radio based” systems are within a factor many thousands to a few million of being adequate.
=====
Now, if this is headed off into a “the government is coming to break down the doors and take away all my toys sort of thing. That’s very much *not* a Time Nuts topic.
Bob
Post by Scott McGrath
And there is the other significant vulnerability since GPS is a MILITARY system the DoD can take it offline for any reason at any time.
Leaving civilian users with nothing,
If its a national security threat its likely the other GNSS systems will be unavailable as well.
Well blow me down. It took some Google Maps fu on the web on my part, but
my time and place does indeed coincide with this “GPS Interference Testing” at
White Sands Missile Range. I just happened to be in my home office watching
several of my GPS-disciplined NTP servers when this occurred. Thanks, Graham!
:John
Post by Graham / KE9H
ZDV DENVER (ARTCC),CO. [Back to Top] !GPS 08/260 (KZDV A0287/18) ZDV NAV
GPS (WSMR GPS 18-20) (INCLUDING WAAS, GBAS, AND ADS-B) MAY NOT BE AVBL WI A
359NM RADIUS CENTERED AT 333345N1063840W (TCS054036) FL400-UNL, 311NM
RADIUS AT FL250, 215NM RADIUS AT 10000FT, 223NM RADIUS AT 4000FT AGL, 169NM
RADIUS AT 50FT AGL DLY 1830-2230 1809031830-1809082230
--
J. L. Sloan Digital Aggregates Corp.
+1 303 940 9064 (O) 3440 Youngfield St. #209
+1 303 489 5178 (M) Wheat Ridge CO 80033 USA
_______________________________________________
To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
and follow the instructions there.
_______________________________________________
To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
and follow the instructions there.
_______________________________________________
To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
and follow the instructions there.
_______________________________________________
To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
and follow the instructions there.
_______________________________________________
time-nuts mailing list -- time-***@lists.febo.com
To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
and follow the instructions there.

_______________________________________________
time-nuts mailing list -- time-***@lists.febo.com
To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
and follow
Scott McGrath
2018-09-07 01:08:21 UTC
Reply
Permalink
Raw Message
As to eLORAN, you can deny positioning but maintain timing service simply by modifying the GRI and since eLORAN is software based thats not a difficult change.

Navigation receivers go into fail but timing receivers only need ONE station. As the users of SRS700’s and Austrons do when Wildwood is active.

With GNSS its a hell of a lot harder and without SA your only option is to turn off all the C/A signals hence denying civillian use of GNSS

I’m pretty sure if a non-state actor was doing weaponized drone attacks with GPS for guidance, GPS for civilian use would be shut down in a NY minute .

Remember govt users would not be affected as they have access to the PPS and the ‘word of the day’ to make it active.

You dont need conspiracies to think of conditions where GPS would be shut down for long periods of time and where reasonable people would agree with the shutdown.

On Sep 6, 2018, at 8:44 PM, Scott McGrath <***@gmail.com> wrote:

Gee, thats strange especially for those of us who ran the Austron comparitors to check our local standards against the LORSTA’s



On Sep 6, 2018, at 8:04 PM, Bob kb8tq <***@n1k.org> wrote:

Hi

No, eLoran *never* on it’s best day could ever deliver the kind of timing that the vast majority
of these systems require. It simply is not and can not do the job. The world has moved *way*
past the sort of timing it can actually deliver.

Bob
Post by Scott McGrath
Actually we DID have a radio based system that provided sufficient accuracy it was called eLORAN but it was killed by US politicians because they did not want a much more inexpensive to operate system ‘competing’ with GPS. Shutting down LORAN saved 32m dollars annually the NAVSTAR GPS program costs billions annually.
Ironically while LORAN’s absolute accuracy is less than GPS, repeatability was much better so fishermen liked LORAN better.
Once again the empty suits won and the navigation and timing community lost.
Wrt cellsites staying operational i imagine the oscillators in holdover would probably remain sufficiently synchronized for a month or so.
Hi
Well, we *do* have experience with that. It was called selective availability. Indeed it might get turned back on again. It’s impact on a properly designed GPSDO - not much. It takes a bit longer to get to best stability. System time wise, it still works “good enough”.
A four hour long test format also does basically nothing to a GPSDO based system. You didn’t read anything in the papers about all cell service in three states going away. The devices did what they are supposed to do and everything did it’s boringly normal thing ….. it worked fine.
I still don’t quite understand just what people think could replace satellite based timing in these systems. None of the “radio based” systems are within a factor many thousands to a few million of being adequate.
=====
Now, if this is headed off into a “the government is coming to break down the doors and take away all my toys sort of thing. That’s very much *not* a Time Nuts topic.
Bob
Post by Scott McGrath
And there is the other significant vulnerability since GPS is a MILITARY system the DoD can take it offline for any reason at any time.
Leaving civilian users with nothing,
If its a national security threat its likely the other GNSS systems will be unavailable as well.
Well blow me down. It took some Google Maps fu on the web on my part, but
my time and place does indeed coincide with this “GPS Interference Testing” at
White Sands Missile Range. I just happened to be in my home office watching
several of my GPS-disciplined NTP servers when this occurred. Thanks, Graham!
:John
Post by Graham / KE9H
ZDV DENVER (ARTCC),CO. [Back to Top] !GPS 08/260 (KZDV A0287/18) ZDV NAV
GPS (WSMR GPS 18-20) (INCLUDING WAAS, GBAS, AND ADS-B) MAY NOT BE AVBL WI A
359NM RADIUS CENTERED AT 333345N1063840W (TCS054036) FL400-UNL, 311NM
RADIUS AT FL250, 215NM RADIUS AT 10000FT, 223NM RADIUS AT 4000FT AGL, 169NM
RADIUS AT 50FT AGL DLY 1830-2230 1809031830-1809082230
--
J. L. Sloan Digital Aggregates Corp.
+1 303 940 9064 (O) 3440 Youngfield St. #209
+1 303 489 5178 (M) Wheat Ridge CO 80033 USA
_______________________________________________
To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
and follow the instructions there.
_______________________________________________
To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
and follow the instructions there.
_______________________________________________
To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
and follow the instructions there.
_______________________________________________
To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
and follow the instructions there.
_______________________________________________
time-nuts mailing list -- time-***@lists.febo.com
To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
and follow the instructions there.

_______________________________________________
time-nuts mailing list -- time-***@lists.febo.com
To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
and follow
Bob kb8tq
2018-09-07 21:18:55 UTC
Reply
Permalink
Raw Message
Hi

You are not trying to run a cell system when checking your local oscillator against LORAN.
It’s two completely different things. The timing requirements of the modern systems are indeed
way past what LORAN can deliver. We’re not talking about 1970’s state of the art anymore. You
need a time source that is in the 10 ns range to keep this stuff running. Multiple microseconds of
error in your timing source aren’t good enough for what they have up and are rolling out. Full
end of holdover spec on many of them is below 2 microseconds. Normal operation is under 100 ns.
Give the cell outfits another couple years and that’s all they will have on the air.


Bob
Post by Scott McGrath
As to eLORAN, you can deny positioning but maintain timing service simply by modifying the GRI and since eLORAN is software based thats not a difficult change.
Navigation receivers go into fail but timing receivers only need ONE station. As the users of SRS700’s and Austrons do when Wildwood is active.
With GNSS its a hell of a lot harder and without SA your only option is to turn off all the C/A signals hence denying civillian use of GNSS
I’m pretty sure if a non-state actor was doing weaponized drone attacks with GPS for guidance, GPS for civilian use would be shut down in a NY minute .
Remember govt users would not be affected as they have access to the PPS and the ‘word of the day’ to make it active.
You dont need conspiracies to think of conditions where GPS would be shut down for long periods of time and where reasonable people would agree with the shutdown.
Gee, thats strange especially for those of us who ran the Austron comparitors to check our local standards against the LORSTA’s
Hi
No, eLoran *never* on it’s best day could ever deliver the kind of timing that the vast majority
of these systems require. It simply is not and can not do the job. The world has moved *way*
past the sort of timing it can actually deliver.
Bob
Post by Scott McGrath
Actually we DID have a radio based system that provided sufficient accuracy it was called eLORAN but it was killed by US politicians because they did not want a much more inexpensive to operate system ‘competing’ with GPS. Shutting down LORAN saved 32m dollars annually the NAVSTAR GPS program costs billions annually.
Ironically while LORAN’s absolute accuracy is less than GPS, repeatability was much better so fishermen liked LORAN better.
Once again the empty suits won and the navigation and timing community lost.
Wrt cellsites staying operational i imagine the oscillators in holdover would probably remain sufficiently synchronized for a month or so.
Hi
Well, we *do* have experience with that. It was called selective availability. Indeed it might get turned back on again. It’s impact on a properly designed GPSDO - not much. It takes a bit longer to get to best stability. System time wise, it still works “good enough”.
A four hour long test format also does basically nothing to a GPSDO based system. You didn’t read anything in the papers about all cell service in three states going away. The devices did what they are supposed to do and everything did it’s boringly normal thing ….. it worked fine.
I still don’t quite understand just what people think could replace satellite based timing in these systems. None of the “radio based” systems are within a factor many thousands to a few million of being adequate.
=====
Now, if this is headed off into a “the government is coming to break down the doors and take away all my toys sort of thing. That’s very much *not* a Time Nuts topic.
Bob
Post by Scott McGrath
And there is the other significant vulnerability since GPS is a MILITARY system the DoD can take it offline for any reason at any time.
Leaving civilian users with nothing,
If its a national security threat its likely the other GNSS systems will be unavailable as well.
Well blow me down. It took some Google Maps fu on the web on my part, but
my time and place does indeed coincide with this “GPS Interference Testing” at
White Sands Missile Range. I just happened to be in my home office watching
several of my GPS-disciplined NTP servers when this occurred. Thanks, Graham!
:John
Post by Graham / KE9H
ZDV DENVER (ARTCC),CO. [Back to Top] !GPS 08/260 (KZDV A0287/18) ZDV NAV
GPS (WSMR GPS 18-20) (INCLUDING WAAS, GBAS, AND ADS-B) MAY NOT BE AVBL WI A
359NM RADIUS CENTERED AT 333345N1063840W (TCS054036) FL400-UNL, 311NM
RADIUS AT FL250, 215NM RADIUS AT 10000FT, 223NM RADIUS AT 4000FT AGL, 169NM
RADIUS AT 50FT AGL DLY 1830-2230 1809031830-1809082230
--
J. L. Sloan Digital Aggregates Corp.
+1 303 940 9064 (O) 3440 Youngfield St. #209
+1 303 489 5178 (M) Wheat Ridge CO 80033 USA
_______________________________________________
To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
and follow the instructions there.
_______________________________________________
To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
and follow the instructions there.
_______________________________________________
To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
and follow the instructions there.
_______________________________________________
To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
and follow the instructions there.
_______________________________________________
To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
and follow the instructions there.
_______________________________________________
To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
and follow the instructions there.
_______________________________________________
time-nuts mailing list -- time-***@lists.febo.com
To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
and follo
Scott McGrath
2018-09-07 23:01:08 UTC
Reply
Permalink
Raw Message
You are SO convinced that GPS will ALWAYS be there, I’m NOT (Think Carrington Event) and i’ve been part of a few disaster exercises where both Internet and GPS were considered ‘down’ for the exercise and these exercises are done in conjunction with the military so PPS was also ‘off the table’.

It was quite an eye opener to see how many networks could not keep time synchronized within 5 minutes much less 5 seconds because of the cheap XO’s used in servers and workstations(NTP will ALWAYS BE AVAILABLE). Just like the old Sun workstations.

It was also fun watching the multimillion dollar Harris radios drift once they no longer had a 10 Mhz input from a GPSDO. One would think the local timebase would be a bit better than it was.

The older ‘Pacer Bounce’ and Falcon series radios did much better because they had good local timebases and made no assumptions of the availability of a external timebase. Whereas the new radios depend upon it.

These exercises are intended to practice restoring government communications after a large scale natural disaster. And without readily available precision time it aint easy.

Its also fun watching executives realizing that their phone during the exercise is a paperweight useful only in weighting down stacks of Form 213’s

Its not for nothing that Symmetricom is building more 5071’s than HP/Agilent ever did.

On Sep 7, 2018, at 5:18 PM, Bob kb8tq <***@n1k.org> wrote:

Hi

You are not trying to run a cell system when checking your local oscillator against LORAN.
It’s two completely different things. The timing requirements of the modern systems are indeed
way past what LORAN can deliver. We’re not talking about 1970’s state of the art anymore. You
need a time source that is in the 10 ns range to keep this stuff running. Multiple microseconds of
error in your timing source aren’t good enough for what they have up and are rolling out. Full
end of holdover spec on many of them is below 2 microseconds. Normal operation is under 100 ns.
Give the cell outfits another couple years and that’s all they will have on the air.


Bob
Post by Scott McGrath
As to eLORAN, you can deny positioning but maintain timing service simply by modifying the GRI and since eLORAN is software based thats not a difficult change.
Navigation receivers go into fail but timing receivers only need ONE station. As the users of SRS700’s and Austrons do when Wildwood is active.
With GNSS its a hell of a lot harder and without SA your only option is to turn off all the C/A signals hence denying civillian use of GNSS
I’m pretty sure if a non-state actor was doing weaponized drone attacks with GPS for guidance, GPS for civilian use would be shut down in a NY minute .
Remember govt users would not be affected as they have access to the PPS and the ‘word of the day’ to make it active.
You dont need conspiracies to think of conditions where GPS would be shut down for long periods of time and where reasonable people would agree with the shutdown.
Gee, thats strange especially for those of us who ran the Austron comparitors to check our local standards against the LORSTA’s
Hi
No, eLoran *never* on it’s best day could ever deliver the kind of timing that the vast majority
of these systems require. It simply is not and can not do the job. The world has moved *way*
past the sort of timing it can actually deliver.
Bob
Post by Scott McGrath
Actually we DID have a radio based system that provided sufficient accuracy it was called eLORAN but it was killed by US politicians because they did not want a much more inexpensive to operate system ‘competing’ with GPS. Shutting down LORAN saved 32m dollars annually the NAVSTAR GPS program costs billions annually.
Ironically while LORAN’s absolute accuracy is less than GPS, repeatability was much better so fishermen liked LORAN better.
Once again the empty suits won and the navigation and timing community lost.
Wrt cellsites staying operational i imagine the oscillators in holdover would probably remain sufficiently synchronized for a month or so.
Hi
Well, we *do* have experience with that. It was called selective availability. Indeed it might get turned back on again. It’s impact on a properly designed GPSDO - not much. It takes a bit longer to get to best stability. System time wise, it still works “good enough”.
A four hour long test format also does basically nothing to a GPSDO based system. You didn’t read anything in the papers about all cell service in three states going away. The devices did what they are supposed to do and everything did it’s boringly normal thing ….. it worked fine.
I still don’t quite understand just what people think could replace satellite based timing in these systems. None of the “radio based” systems are within a factor many thousands to a few million of being adequate.
=====
Now, if this is headed off into a “the government is coming to break down the doors and take away all my toys sort of thing. That’s very much *not* a Time Nuts topic.
Bob
Post by Scott McGrath
And there is the other significant vulnerability since GPS is a MILITARY system the DoD can take it offline for any reason at any time.
Leaving civilian users with nothing,
If its a national security threat its likely the other GNSS systems will be unavailable as well.
Well blow me down. It took some Google Maps fu on the web on my part, but
my time and place does indeed coincide with this “GPS Interference Testing” at
White Sands Missile Range. I just happened to be in my home office watching
several of my GPS-disciplined NTP servers when this occurred. Thanks, Graham!
:John
Post by Graham / KE9H
ZDV DENVER (ARTCC),CO. [Back to Top] !GPS 08/260 (KZDV A0287/18) ZDV NAV
GPS (WSMR GPS 18-20) (INCLUDING WAAS, GBAS, AND ADS-B) MAY NOT BE AVBL WI A
359NM RADIUS CENTERED AT 333345N1063840W (TCS054036) FL400-UNL, 311NM
RADIUS AT FL250, 215NM RADIUS AT 10000FT, 223NM RADIUS AT 4000FT AGL, 169NM
RADIUS AT 50FT AGL DLY 1830-2230 1809031830-1809082230
--
J. L. Sloan Digital Aggregates Corp.
+1 303 940 9064 (O) 3440 Youngfield St. #209
+1 303 489 5178 (M) Wheat Ridge CO 80033 USA
_______________________________________________
To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
and follow the instructions there.
_______________________________________________
To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
and follow the instructions there.
_______________________________________________
To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
and follow the instructions there.
_______________________________________________
To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
and follow the instructions there.
_______________________________________________
To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
and follow the instructions there.
_______________________________________________
To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
and follow the instructions there.
_______________________________________________
time-nuts mailing list -- time-***@lists.febo.com
To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
and follow the instructions there.

_______________________________________________
time-nuts mailing list -- time-***@lists.febo.com
To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts
jimlux
2018-09-07 23:51:17 UTC
Reply
Permalink
Raw Message
Post by Scott McGrath
You are SO convinced that GPS will ALWAYS be there, I’m NOT (Think Carrington Event) and i’ve been part of a few disaster exercises where both Internet and GPS were considered ‘down’ for the exercise and these exercises are done in conjunction with the military so PPS was also ‘off the table’.
It was quite an eye opener to see how many networks could not keep time synchronized within 5 minutes much less 5 seconds because of the cheap XO’s used in servers and workstations(NTP will ALWAYS BE AVAILABLE). Just like the old Sun workstations.
I assume you're using network in the sense of "group of computers that
has to keep common time, but are not physically connected to the same
ethernet", because NTP *will* keep everyone together - *if properly
configured"

I suspect the latter is not always true - people assuming that
time.microsoft.com is always available, for instance.

In which case the exercise where "external internet" goes away is a
valuable one, because it exposes the vulnerability.

But in general, if you've got physical infrastructure to connect the
boxes via network, keeping within "seconds" should be straightforward.
Appropriate failover time sources, etc.


Yes, GPSDOs provided an "easy" way to get good time accuracy across a
geographical area without having to think about disaster recovery. It
solves the "simultaneity of database updates" problem for a few thousand
bucks. While hiding the bigger synchronization issue under the rug.
Post by Scott McGrath
It was also fun watching the multimillion dollar Harris radios drift once they no longer had a 10 Mhz input from a GPSDO. One would think the local timebase would be a bit better than it was.
But what sort of requirement is there? Obviously, it's not the NIST HF
SSB of 20Hz (roughly 1 ppm), because I'd find it hard to believe a GPSDO
couldn't hold 1ppm for a year, without a GPS signal.
Post by Scott McGrath
The older ‘Pacer Bounce’ and Falcon series radios did much better because they had good local timebases and made no assumptions of the availability of a external timebase. Whereas the new radios depend upon it.
But nothing says that you can't have a reliable external timebase - an
OCXO and a battery backup, if nothing else.
Post by Scott McGrath
These exercises are intended to practice restoring government communications after a large scale natural disaster. And without readily available precision time it aint easy.
Yes - it's non trivial - it's well out of most people's "I know how to
do that" bucket, and needs a significant amount of network and system
knowledge and "block to block" interaction knowledge that typically
doesn't exist.
Post by Scott McGrath
Its also fun watching executives realizing that their phone during the exercise is a paperweight useful only in weighting down stacks of Form 213’s
Its not for nothing that Symmetricom is building more 5071’s than HP/Agilent ever did.
I wonder if CSAC devices will have significant traction - The CSAC
provides ppb sort of accuracy out of the box without having to think
about it, and doesn't cost anywhere near what a 5071 does.
_______________________________________________
time-nuts mailing list -- time-***@lists.febo.com
To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
and follow the instruc
Bob kb8tq
2018-09-08 00:31:32 UTC
Reply
Permalink
Raw Message
Hi

This is Time Nuts, not end of the world nuts …..

I most certainly did *not* design these systems. The *do* have timing requirements. If those requirements
are not met, they stop working. That’s just the way it goes. Designing these systems at the timing level was
done a decade ago. You can object to what they did, it’s about ten years to late to change anything. Tight timing
gives then more capacity … tough to argue with even if you weren’t to late.

If *you* believe there is an alternative system now in existence that will supply the timing these systems require …
that *is* a Time Nuts topic. So, let’s hear about the numbers on the system you believe will supply what’s needed.
I think we’ve all heard plenty of “the world is ending” stuff.

Bob
Post by Scott McGrath
You are SO convinced that GPS will ALWAYS be there, I’m NOT (Think Carrington Event) and i’ve been part of a few disaster exercises where both Internet and GPS were considered ‘down’ for the exercise and these exercises are done in conjunction with the military so PPS was also ‘off the table’.
It was quite an eye opener to see how many networks could not keep time synchronized within 5 minutes much less 5 seconds because of the cheap XO’s used in servers and workstations(NTP will ALWAYS BE AVAILABLE). Just like the old Sun workstations.
It was also fun watching the multimillion dollar Harris radios drift once they no longer had a 10 Mhz input from a GPSDO. One would think the local timebase would be a bit better than it was.
The older ‘Pacer Bounce’ and Falcon series radios did much better because they had good local timebases and made no assumptions of the availability of a external timebase. Whereas the new radios depend upon it.
These exercises are intended to practice restoring government communications after a large scale natural disaster. And without readily available precision time it aint easy.
Its also fun watching executives realizing that their phone during the exercise is a paperweight useful only in weighting down stacks of Form 213’s
Its not for nothing that Symmetricom is building more 5071’s than HP/Agilent ever did.
Hi
You are not trying to run a cell system when checking your local oscillator against LORAN.
It’s two completely different things. The timing requirements of the modern systems are indeed
way past what LORAN can deliver. We’re not talking about 1970’s state of the art anymore. You
need a time source that is in the 10 ns range to keep this stuff running. Multiple microseconds of
error in your timing source aren’t good enough for what they have up and are rolling out. Full
end of holdover spec on many of them is below 2 microseconds. Normal operation is under 100 ns.
Give the cell outfits another couple years and that’s all they will have on the air.
Bob
Post by Scott McGrath
As to eLORAN, you can deny positioning but maintain timing service simply by modifying the GRI and since eLORAN is software based thats not a difficult change.
Navigation receivers go into fail but timing receivers only need ONE station. As the users of SRS700’s and Austrons do when Wildwood is active.
With GNSS its a hell of a lot harder and without SA your only option is to turn off all the C/A signals hence denying civillian use of GNSS
I’m pretty sure if a non-state actor was doing weaponized drone attacks with GPS for guidance, GPS for civilian use would be shut down in a NY minute .
Remember govt users would not be affected as they have access to the PPS and the ‘word of the day’ to make it active.
You dont need conspiracies to think of conditions where GPS would be shut down for long periods of time and where reasonable people would agree with the shutdown.
Gee, thats strange especially for those of us who ran the Austron comparitors to check our local standards against the LORSTA’s
Hi
No, eLoran *never* on it’s best day could ever deliver the kind of timing that the vast majority
of these systems require. It simply is not and can not do the job. The world has moved *way*
past the sort of timing it can actually deliver.
Bob
Post by Scott McGrath
Actually we DID have a radio based system that provided sufficient accuracy it was called eLORAN but it was killed by US politicians because they did not want a much more inexpensive to operate system ‘competing’ with GPS. Shutting down LORAN saved 32m dollars annually the NAVSTAR GPS program costs billions annually.
Ironically while LORAN’s absolute accuracy is less than GPS, repeatability was much better so fishermen liked LORAN better.
Once again the empty suits won and the navigation and timing community lost.
Wrt cellsites staying operational i imagine the oscillators in holdover would probably remain sufficiently synchronized for a month or so.
Hi
Well, we *do* have experience with that. It was called selective availability. Indeed it might get turned back on again. It’s impact on a properly designed GPSDO - not much. It takes a bit longer to get to best stability. System time wise, it still works “good enough”.
A four hour long test format also does basically nothing to a GPSDO based system. You didn’t read anything in the papers about all cell service in three states going away. The devices did what they are supposed to do and everything did it’s boringly normal thing ….. it worked fine.
I still don’t quite understand just what people think could replace satellite based timing in these systems. None of the “radio based” systems are within a factor many thousands to a few million of being adequate.
=====
Now, if this is headed off into a “the government is coming to break down the doors and take away all my toys sort of thing. That’s very much *not* a Time Nuts topic.
Bob
Post by Scott McGrath
And there is the other significant vulnerability since GPS is a MILITARY system the DoD can take it offline for any reason at any time.
Leaving civilian users with nothing,
If its a national security threat its likely the other GNSS systems will be unavailable as well.
Well blow me down. It took some Google Maps fu on the web on my part, but
my time and place does indeed coincide with this “GPS Interference Testing” at
White Sands Missile Range. I just happened to be in my home office watching
several of my GPS-disciplined NTP servers when this occurred. Thanks, Graham!
:John
Post by Graham / KE9H
ZDV DENVER (ARTCC),CO. [Back to Top] !GPS 08/260 (KZDV A0287/18) ZDV NAV
GPS (WSMR GPS 18-20) (INCLUDING WAAS, GBAS, AND ADS-B) MAY NOT BE AVBL WI A
359NM RADIUS CENTERED AT 333345N1063840W (TCS054036) FL400-UNL, 311NM
RADIUS AT FL250, 215NM RADIUS AT 10000FT, 223NM RADIUS AT 4000FT AGL, 169NM
RADIUS AT 50FT AGL DLY 1830-2230 1809031830-1809082230
--
J. L. Sloan Digital Aggregates Corp.
+1 303 940 9064 (O) 3440 Youngfield St. #209
+1 303 489 5178 (M) Wheat Ridge CO 80033 USA
_______________________________________________
To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
and follow the instructions there.
_______________________________________________
To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
and follow the instructions there.
_______________________________________________
To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
and follow the instructions there.
_______________________________________________
To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
and follow the instructions there.
_______________________________________________
To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
and follow the instructions there.
_______________________________________________
To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
and follow the instructions there.
_______________________________________________
To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
and follow the instructions there.
_______________________________________________
To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
and follow the instructions there.
_______________________________________________
time-nuts mailing list -- time-***@lists.febo.com
To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
and
Ruslan Nabioullin
2018-09-08 22:54:40 UTC
Reply
Permalink
Raw Message
Post by Bob kb8tq
This is Time Nuts, not end of the world nuts …..
...
I think we’ve all heard plenty of “the world is ending” stuff.
But the availability of a T&F service under adverse conditions and the
ability of a system which consumes a T&F reference to gracefully degrade
its functionality upon degradation or absence of reference input(s) are
features/figures of merit---I do not see how discussion of that aspect can
be considered to be offtopic.

-Ruslan
--
Ruslan Nabioullin
Wittgenstein Laboratories
***@gmail.com
(508) 523-8535
50 Louise Dr.
Hollis, NH 03049
_______________________________________________
time-nuts mailing list -- time-***@lists.febo.com
To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
and follow the instructio
Dana Whitlow
2018-09-08 23:26:47 UTC
Reply
Permalink
Raw Message
I argue that when the "big one" happens, getting back to where we are
technologically
will be in large part a bootstrapping kind of affair. And I believe that
starting off with
WWV* will be a far better starting point than starting with sun clocks and
dripping
water.

Dana
Post by Ruslan Nabioullin
Post by Bob kb8tq
This is Time Nuts, not end of the world nuts …..
...
I think we’ve all heard plenty of “the world is ending” stuff.
But the availability of a T&F service under adverse conditions and the
ability of a system which consumes a T&F reference to gracefully degrade
its functionality upon degradation or absence of reference input(s) are
features/figures of merit---I do not see how discussion of that aspect can
be considered to be offtopic.
-Ruslan
--
Ruslan Nabioullin
Wittgenstein Laboratories
(508) 523-8535
50 Louise Dr.
Hollis, NH 03049
_______________________________________________
To unsubscribe, go to http://lists.febo.com/mailman/
listinfo/time-nuts_lists.febo.com
and follow the instructions there.
_______________________________________________
time-nuts mailing list -- time-***@lists.febo.com
To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
and follow the instru
William H. Fite
2018-09-09 00:11:07 UTC
Reply
Permalink
Raw Message
<Donning asbestos underwear>

Gentlemen, I've found this discussion interesting and informative. This
household works on quantum information theory rather than engineering so
there is much for us to learn.

I must observe that if an event takes out the entire GPS system (which a
Carrington event would not do) we will have issues a great deal more
immediate and pressing than getting hyper-precise timing systems restored.

And speaking of Carrington events, how many of us have our equipment
surrounded by Faraday cages and supplied with off-grid power? Because
without those, we won't have instruments to measure T&F at home or even in
a great many labs and businesses.

Just a thought.....
Post by Dana Whitlow
I argue that when the "big one" happens, getting back to where we are
technologically
will be in large part a bootstrapping kind of affair. And I believe that
starting off with
WWV* will be a far better starting point than starting with sun clocks and
dripping
water.
Dana
Post by Ruslan Nabioullin
Post by Bob kb8tq
This is Time Nuts, not end of the world nuts …..
...
I think we’ve all heard plenty of “the world is ending” stuff.
But the availability of a T&F service under adverse conditions and the
ability of a system which consumes a T&F reference to gracefully degrade
its functionality upon degradation or absence of reference input(s) are
features/figures of merit---I do not see how discussion of that aspect
can
Post by Ruslan Nabioullin
be considered to be offtopic.
-Ruslan
--
Ruslan Nabioullin
Wittgenstein Laboratories
(508) 523-8535
50 Louise Dr.
Hollis, NH 03049
_______________________________________________
To unsubscribe, go to http://lists.febo.com/mailman/
listinfo/time-nuts_lists.febo.com
and follow the instructions there.
_______________________________________________
To unsubscribe, go to http://lists.febo.com/mailman/
listinfo/time-nuts_lists.febo.com
and follow the instructions there.
--
Patriotism is supporting your country all the time, and your government
when it deserves it.
--Mark Twain

We may be surprised at the people we find in heaven. God has a soft spot
for sinners. His standards are quite low.
--Desmond Tutu
_______________________________________________
time-nuts mailing list -- time-***@lists.febo.com
To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
Scott McGrath
2018-09-09 01:30:32 UTC
Reply
Permalink
Raw Message
Actually

I do have much of my equipment inside a shield room, not for tinfoil hat reasons but to keep experimental systems from causing interference and to eliminate existing RF sources in the 800 Mhz to 8 Ghz range as error sources in measurements.

If one is concerned there are lots of old screen rooms coming up for sale on e-bay as WiFi manufacturers prepare to dip their toes into bands above 10 Ghz and many of the old ones were only good to 6-8 Ghz.

As to backup generators I have a modern one and an ‘old school’ mechanically governed one with magneto ignition. I keep that one mainly because i like its Art Deco design. Sometimes bring it to local Ag Fair to display among the gear from that era.

Content by Scott
Typos by Siri

On Sep 8, 2018, at 8:11 PM, William H. Fite <***@gmail.com> wrote:

<Donning asbestos underwear>

Gentlemen, I've found this discussion interesting and informative. This
household works on quantum information theory rather than engineering so
there is much for us to learn.

I must observe that if an event takes out the entire GPS system (which a
Carrington event would not do) we will have issues a great deal more
immediate and pressing than getting hyper-precise timing systems restored.

And speaking of Carrington events, how many of us have our equipment
surrounded by Faraday cages and supplied with off-grid power? Because
without those, we won't have instruments to measure T&F at home or even in
a great many labs and businesses.

Just a thought.....
Post by Dana Whitlow
I argue that when the "big one" happens, getting back to where we are
technologically
will be in large part a bootstrapping kind of affair. And I believe that
starting off with
WWV* will be a far better starting point than starting with sun clocks and
dripping
water.
Dana
Post by Ruslan Nabioullin
Post by Bob kb8tq
This is Time Nuts, not end of the world nuts …..
...
I think we’ve all heard plenty of “the world is ending” stuff.
But the availability of a T&F service under adverse conditions and the
ability of a system which consumes a T&F reference to gracefully degrade
its functionality upon degradation or absence of reference input(s) are
features/figures of merit---I do not see how discussion of that aspect
can
Post by Ruslan Nabioullin
be considered to be offtopic.
-Ruslan
--
Ruslan Nabioullin
Wittgenstein Laboratories
(508) 523-8535
50 Louise Dr.
Hollis, NH 03049
_______________________________________________
To unsubscribe, go to http://lists.febo.com/mailman/
listinfo/time-nuts_lists.febo.com
and follow the instructions there.
_______________________________________________
To unsubscribe, go to http://lists.febo.com/mailman/
listinfo/time-nuts_lists.febo.com
and follow the instructions there.
--
Patriotism is supporting your country all the time, and your government
when it deserves it.
--Mark Twain

We may be surprised at the people we find in heaven. God has a soft spot
for sinners. His standards are quite low.
--Desmond Tutu
_______________________________________________
time-nuts mailing list -- time-***@lists.febo.com
To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
and follow the instructions there.

_______________________________________________
time-nuts mailing list -- time-***@lists.febo.com
To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.
William H. Fite
2018-09-09 01:48:43 UTC
Reply
Permalink
Raw Message
We sound like we could be cousins, Scott. When we bought our current house,
I discovered that the previous owner had built a Faraday cage in a small
room off the basement. I put all my stuff in there. I also have a generator
with magneto ignition so I should be good to go when the end-of-the-world
arrives.
Post by Scott McGrath
Actually
I do have much of my equipment inside a shield room, not for tinfoil hat
reasons but to keep experimental systems from causing interference and to
eliminate existing RF sources in the 800 Mhz to 8 Ghz range as error
sources in measurements.
If one is concerned there are lots of old screen rooms coming up for sale
on e-bay as WiFi manufacturers prepare to dip their toes into bands above
10 Ghz and many of the old ones were only good to 6-8 Ghz.
As to backup generators I have a modern one and an ‘old school’
mechanically governed one with magneto ignition. I keep that one mainly
because i like its Art Deco design. Sometimes bring it to local Ag Fair
to display among the gear from that era.
Content by Scott
Typos by Siri
<Donning asbestos underwear>
Gentlemen, I've found this discussion interesting and informative. This
household works on quantum information theory rather than engineering so
there is much for us to learn.
I must observe that if an event takes out the entire GPS system (which a
Carrington event would not do) we will have issues a great deal more
immediate and pressing than getting hyper-precise timing systems restored.
And speaking of Carrington events, how many of us have our equipment
surrounded by Faraday cages and supplied with off-grid power? Because
without those, we won't have instruments to measure T&F at home or even in
a great many labs and businesses.
Just a thought.....
Post by Dana Whitlow
I argue that when the "big one" happens, getting back to where we are
technologically
will be in large part a bootstrapping kind of affair. And I believe that
starting off with
WWV* will be a far better starting point than starting with sun clocks
and
Post by Dana Whitlow
dripping
water.
Dana
Post by Ruslan Nabioullin
Post by Bob kb8tq
This is Time Nuts, not end of the world nuts …..
...
I think we’ve all heard plenty of “the world is ending” stuff.
But the availability of a T&F service under adverse conditions and the
ability of a system which consumes a T&F reference to gracefully degrade
its functionality upon degradation or absence of reference input(s) are
features/figures of merit---I do not see how discussion of that aspect
can
Post by Ruslan Nabioullin
be considered to be offtopic.
-Ruslan
--
Ruslan Nabioullin
Wittgenstein Laboratories
(508) 523-8535
50 Louise Dr.
Hollis, NH 03049
_______________________________________________
To unsubscribe, go to http://lists.febo.com/mailman/
listinfo/time-nuts_lists.febo.com
and follow the instructions there.
_______________________________________________
To unsubscribe, go to http://lists.febo.com/mailman/
listinfo/time-nuts_lists.febo.com
and follow the instructions there.
--
Patriotism is supporting your country all the time, and your government
when it deserves it.
--Mark Twain
We may be surprised at the people we find in heaven. God has a soft spot
for sinners. His standards are quite low.
--Desmond Tutu
_______________________________________________
To unsubscribe, go to http://lists.febo.com/mailman/
listinfo/time-nuts_lists.febo.com
and follow the instructions there.
_______________________________________________
To unsubscribe, go to http://lists.febo.com/mailman/
listinfo/time-nuts_lists.febo.com
and follow the instructions there.
--
Patriotism is supporting your country all the time, and your government
when it deserves it.
--Mark Twain

We may be surprised at the people we find in heaven. God has a soft spot
for sinners. His standards are quite low.
--Desmond Tutu
_______________________________________________
time-nuts mailing list -- time-***@lists.febo.com
To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
and follow the instru
Scott McGrath
2018-09-09 13:08:45 UTC
Reply
Permalink
Raw Message
My company paid for my shield room the real trick was getting the door in which weighed 600-800 pounds.

As to the old generator I restore old machinery as another hobby for the times I want to disengage brain. But photoetched brass id plates show so much more thought than thermal printed labels

Content by Scott
Typos by Siri

On Sep 8, 2018, at 9:48 PM, William H. Fite <***@gmail.com> wrote:

We sound like we could be cousins, Scott. When we bought our current house,
I discovered that the previous owner had built a Faraday cage in a small
room off the basement. I put all my stuff in there. I also have a generator
with magneto ignition so I should be good to go when the end-of-the-world
arrives.
Post by Scott McGrath
Actually
I do have much of my equipment inside a shield room, not for tinfoil hat
reasons but to keep experimental systems from causing interference and to
eliminate existing RF sources in the 800 Mhz to 8 Ghz range as error
sources in measurements.
If one is concerned there are lots of old screen rooms coming up for sale
on e-bay as WiFi manufacturers prepare to dip their toes into bands above
10 Ghz and many of the old ones were only good to 6-8 Ghz.
As to backup generators I have a modern one and an ‘old school’
mechanically governed one with magneto ignition. I keep that one mainly
because i like its Art Deco design. Sometimes bring it to local Ag Fair
to display among the gear from that era.
Content by Scott
Typos by Siri
<Donning asbestos underwear>
Gentlemen, I've found this discussion interesting and informative. This
household works on quantum information theory rather than engineering so
there is much for us to learn.
I must observe that if an event takes out the entire GPS system (which a
Carrington event would not do) we will have issues a great deal more
immediate and pressing than getting hyper-precise timing systems restored.
And speaking of Carrington events, how many of us have our equipment
surrounded by Faraday cages and supplied with off-grid power? Because
without those, we won't have instruments to measure T&F at home or even in
a great many labs and businesses.
Just a thought.....
Post by Dana Whitlow
I argue that when the "big one" happens, getting back to where we are
technologically
will be in large part a bootstrapping kind of affair. And I believe that
starting off with
WWV* will be a far better starting point than starting with sun clocks
and
Post by Dana Whitlow
dripping
water.
Dana
Post by Ruslan Nabioullin
Post by Bob kb8tq
This is Time Nuts, not end of the world nuts …..
...
I think we’ve all heard plenty of “the world is ending” stuff.
But the availability of a T&F service under adverse conditions and the
ability of a system which consumes a T&F reference to gracefully degrade
its functionality upon degradation or absence of reference input(s) are
features/figures of merit---I do not see how discussion of that aspect
can
Post by Ruslan Nabioullin
be considered to be offtopic.
-Ruslan
--
Ruslan Nabioullin
Wittgenstein Laboratories
(508) 523-8535
50 Louise Dr.
Hollis, NH 03049
_______________________________________________
To unsubscribe, go to http://lists.febo.com/mailman/
listinfo/time-nuts_lists.febo.com
and follow the instructions there.
_______________________________________________
To unsubscribe, go to http://lists.febo.com/mailman/
listinfo/time-nuts_lists.febo.com
and follow the instructions there.
--
Patriotism is supporting your country all the time, and your government
when it deserves it.
--Mark Twain
We may be surprised at the people we find in heaven. God has a soft spot
for sinners. His standards are quite low.
--Desmond Tutu
_______________________________________________
To unsubscribe, go to http://lists.febo.com/mailman/
listinfo/time-nuts_lists.febo.com
and follow the instructions there.
_______________________________________________
To unsubscribe, go to http://lists.febo.com/mailman/
listinfo/time-nuts_lists.febo.com
and follow the instructions there.
--
Patriotism is supporting your country all the time, and your government
when it deserves it.
--Mark Twain

We may be surprised at the people we find in heaven. God has a soft spot
for sinners. His standards are quite low.
--Desmond Tutu
_______________________________________________
time-nuts mailing list -- time-***@lists.febo.com
To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
and follow the instructions there.

_______________________________________________
time-nuts mailing list -- time-***@lists.febo.com
To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nu
Bob Martin
2018-09-07 22:42:25 UTC
Reply
Permalink
Raw Message
Here is an interesting and fairly recent link regarding eloran and
telecom.

https://rntfnd.org/2017/09/17/telecom-organization-recommends-eloran-system/

The report is here:
https://access.atis.org/apps/group_public/download.php/36304/ATIS-0900005.pdf

Page 11 has an nice table called "Time and phase end application
synchronization requirements. It then really gets interesting
starting on page 14.

Again, I have no skin in this discussion other than it would be neat
if that old gear I designed were to be resurrected! It does appear
that poor old Loran has it's share of lovers and haters. I wonder if
the numbers and assertions in this document truly reflect reality?

As I said before, all this Time Nut debating over GPS dependency
appears to be raging at many levels of government and industry.

Best,

Bob Martin
Post by Bob kb8tq
Hi
You are not trying to run a cell system when checking your local oscillator against LORAN.
It’s two completely different things. The timing requirements of the modern systems are indeed
way past what LORAN can deliver. We’re not talking about 1970’s state of the art anymore. You
need a time source that is in the 10 ns range to keep this stuff running. Multiple microseconds of
error in your timing source aren’t good enough for what they have up and are rolling out. Full
end of holdover spec on many of them is below 2 microseconds. Normal operation is under 100 ns.
Give the cell outfits another couple years and that’s all they will have on the air.
Bob
Post by Scott McGrath
As to eLORAN, you can deny positioning but maintain timing service simply by modifying the GRI and since eLORAN is software based thats not a difficult change.
Navigation receivers go into fail but timing receivers only need ONE station. As the users of SRS700’s and Austrons do when Wildwood is active.
With GNSS its a hell of a lot harder and without SA your only option is to turn off all the C/A signals hence denying civillian use of GNSS
I’m pretty sure if a non-state actor was doing weaponized drone attacks with GPS for guidance, GPS for civilian use would be shut down in a NY minute .
Remember govt users would not be affected as they have access to the PPS and the ‘word of the day’ to make it active.
You dont need conspiracies to think of conditions where GPS would be shut down for long periods of time and where reasonable people would agree with the shutdown.
Gee, thats strange especially for those of us who ran the Austron comparitors to check our local standards against the LORSTA’s
Hi
No, eLoran *never* on it’s best day could ever deliver the kind of timing that the vast majority
of these systems require. It simply is not and can not do the job. The world has moved *way*
past the sort of timing it can actually deliver.
Bob
Post by Scott McGrath
Actually we DID have a radio based system that provided sufficient accuracy it was called eLORAN but it was killed by US politicians because they did not want a much more inexpensive to operate system ‘competing’ with GPS. Shutting down LORAN saved 32m dollars annually the NAVSTAR GPS program costs billions annually.
Ironically while LORAN’s absolute accuracy is less than GPS, repeatability was much better so fishermen liked LORAN better.
Once again the empty suits won and the navigation and timing community lost.
Wrt cellsites staying operational i imagine the oscillators in holdover would probably remain sufficiently synchronized for a month or so.
Hi
Well, we *do* have experience with that. It was called selective availability. Indeed it might get turned back on again. It’s impact on a properly designed GPSDO - not much. It takes a bit longer to get to best stability. System time wise, it still works “good enough”.
A four hour long test format also does basically nothing to a GPSDO based system. You didn’t read anything in the papers about all cell service in three states going away. The devices did what they are supposed to do and everything did it’s boringly normal thing ….. it worked fine.
I still don’t quite understand just what people think could replace satellite based timing in these systems. None of the “radio based” systems are within a factor many thousands to a few million of being adequate.
=====
Now, if this is headed off into a “the government is coming to break down the doors and take away all my toys sort of thing. That’s very much *not* a Time Nuts topic.
Bob
Post by Scott McGrath
And there is the other significant vulnerability since GPS is a MILITARY system the DoD can take it offline for any reason at any time.
Leaving civilian users with nothing,
If its a national security threat its likely the other GNSS systems will be unavailable as well.
Well blow me down. It took some Google Maps fu on the web on my part, but
my time and place does indeed coincide with this “GPS Interference Testing” at
White Sands Missile Range. I just happened to be in my home office watching
several of my GPS-disciplined NTP servers when this occurred. Thanks, Graham!
:John
Post by Graham / KE9H
ZDV DENVER (ARTCC),CO. [Back to Top] !GPS 08/260 (KZDV A0287/18) ZDV NAV
GPS (WSMR GPS 18-20) (INCLUDING WAAS, GBAS, AND ADS-B) MAY NOT BE AVBL WI A
359NM RADIUS CENTERED AT 333345N1063840W (TCS054036) FL400-UNL, 311NM
RADIUS AT FL250, 215NM RADIUS AT 10000FT, 223NM RADIUS AT 4000FT AGL, 169NM
RADIUS AT 50FT AGL DLY 1830-2230 1809031830-1809082230
--
J. L. Sloan Digital Aggregates Corp.
+1 303 940 9064 (O) 3440 Youngfield St. #209
+1 303 489 5178 (M) Wheat Ridge CO 80033 USA
_______________________________________________
To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
and follow the instructions there.
_______________________________________________
To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
and follow the instructions there.
_______________________________________________
To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
and follow the instructions there.
_______________________________________________
To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
and follow the instructions there.
_______________________________________________
To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
and follow the instructions there.
_______________________________________________
To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
and follow the instructions there.
_______________________________________________
To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
and follow the instructions there.
_______________________________________________
time-nuts mailing list -- time-***@lists.febo.com
To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
and follo
Bob Martin
2018-09-07 00:25:24 UTC
Reply
Permalink
Raw Message
Hi,

This is so not my area of interest but I did come across the
following quote from the link listed below.

"A backup system is also a possible element. The British have
demonstrated that eLoran can deliver time with 50 nanoseconds
accuracy or better “pretty much anywhere you want to,” said Dana
Goward, president of the Resilient Navigation and Timing Foundation."

http://insidegnss.com/broad-effort-underway-on-assured-accurate-time-for-critical-infrastructure/

I'm sure someone will identify some hidden "but" in the above claim.

I designed the timing hardware for the Loran upgrade well over 10
years ago and haven't thought about it until now. It is fascinating
to me that it is still alive and twitching even after it was killed off.

It is also interesting to see that the Time-Nut concern about GPS
vulnerability is shared by many organizations and governments.

Best,


Bob Martin
Post by Bob kb8tq
Hi
No, eLoran *never* on it’s best day could ever deliver the kind of timing that the vast majority
of these systems require. It simply is not and can not do the job. The world has moved *way*
past the sort of timing it can actually deliver.
Bob
Post by Scott McGrath
Actually we DID have a radio based system that provided sufficient accuracy it was called eLORAN but it was killed by US politicians because they did not want a much more inexpensive to operate system ‘competing’ with GPS. Shutting down LORAN saved 32m dollars annually the NAVSTAR GPS program costs billions annually.
Ironically while LORAN’s absolute accuracy is less than GPS, repeatability was much better so fishermen liked LORAN better.
Once again the empty suits won and the navigation and timing community lost.
Wrt cellsites staying operational i imagine the oscillators in holdover would probably remain sufficiently synchronized for a month or so.
Hi
Well, we *do* have experience with that. It was called selective availability. Indeed it might get turned back on again. It’s impact on a properly designed GPSDO - not much. It takes a bit longer to get to best stability. System time wise, it still works “good enough”.
A four hour long test format also does basically nothing to a GPSDO based system. You didn’t read anything in the papers about all cell service in three states going away. The devices did what they are supposed to do and everything did it’s boringly normal thing ….. it worked fine.
I still don’t quite understand just what people think could replace satellite based timing in these systems. None of the “radio based” systems are within a factor many thousands to a few million of being adequate.
=====
Now, if this is headed off into a “the government is coming to break down the doors and take away all my toys sort of thing. That’s very much *not* a Time Nuts topic.
Bob
Post by Scott McGrath
And there is the other significant vulnerability since GPS is a MILITARY system the DoD can take it offline for any reason at any time.
Leaving civilian users with nothing,
If its a national security threat its likely the other GNSS systems will be unavailable as well.
Well blow me down. It took some Google Maps fu on the web on my part, but
my time and place does indeed coincide with this “GPS Interference Testing” at
White Sands Missile Range. I just happened to be in my home office watching
several of my GPS-disciplined NTP servers when this occurred. Thanks, Graham!
:John
Post by Graham / KE9H
ZDV DENVER (ARTCC),CO. [Back to Top] !GPS 08/260 (KZDV A0287/18) ZDV NAV
GPS (WSMR GPS 18-20) (INCLUDING WAAS, GBAS, AND ADS-B) MAY NOT BE AVBL WI A
359NM RADIUS CENTERED AT 333345N1063840W (TCS054036) FL400-UNL, 311NM
RADIUS AT FL250, 215NM RADIUS AT 10000FT, 223NM RADIUS AT 4000FT AGL, 169NM
RADIUS AT 50FT AGL DLY 1830-2230 1809031830-1809082230
--
J. L. Sloan Digital Aggregates Corp.
+1 303 940 9064 (O) 3440 Youngfield St. #209
+1 303 489 5178 (M) Wheat Ridge CO 80033 USA
_______________________________________________
To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
and follow the instructions there.
_______________________________________________
To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
and follow the instructions there.
_______________________________________________
To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
and follow the instructions there.
_______________________________________________
To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
and follow the instructions there.
_______________________________________________
To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
and follow the instructions there.
_______________________________________________
time-nuts mailing list -- time-***@lists.febo.com
To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
and follow the instructions the
Dr. David Kirkby
2018-09-06 15:30:38 UTC
Reply
Permalink
Raw Message
Post by John Sloan
Yesterday (2018-09-03) afternoon (about 22:00UTC, 16:00MDT) I noticed one
of my three home-made GPS-disciplined NTP servers had lost its GPS lock.
After some forensics on my part, this (2018-09-04) morning (about 16:00UTC,
10:00MDT) I replaced the amplified antenna, and the device reacquired its
lock. I figured it was just an antenna failures; this is an amplified
filtered antenna so it has active electronics.
Then just an hour or so later, I noticed one of my commercial
GPS-disciplined NTP servers (TimeMachines) had lost the GPS 1PPS timing
signal, but indicated it still had GPS lock. (I
No clue what's going on in my suburb near Golden Colorado. But I’m a
little freaked out. Trying to figure out which rule, [1] It’s something
stupid I’ve done, or [2] I am not unique, to apply.
:John
I know someone else who had a similar problem. It turned out to be a fault
in one of the active antennas which went into self-oscillation, which
jammed the other GPS receivers.



Dave.
_______________________________________________
time-nuts mailing list -- time-***@lists.febo.com
To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
and follow the instructio
Mark Sims
2018-09-06 21:58:38 UTC
Reply
Permalink
Raw Message
I read that the latest GPS sats don't even have the ability to implement selective availability... seems a dubious claim to me, though.

---------------------
Post by Bob kb8tq
Indeed it might get turned back on again.
_______________________________________________
time-nuts mailing list -- time-***@lists.febo.com
To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
and follow the instructions there.
Bob Martin
2018-09-06 23:05:01 UTC
Reply
Permalink
Raw Message
GPS.gov: Selective Availability
https://www.gps.gov/systems/gps/modernization/sa/
Sep 23, 2016 - The United States has no intent to ever use Selective
Availability again. In September 2007, the U.S. government announced
its decision to procure the future generation of GPS satellites,
known as GPS III, without the SA feature.

Navstar: GPS Satellite Network - Space.com
https://www.space.com › Science & Astronomy
Apr 26, 2018 - GPS III's new L1C civil signal also will make it the
first GPS satellite ... With selective availability not included on
the latest GPS satellites, the ...

Hopefully this won't devolve into a discussion about whether one can
trust the US Government.

Bob Martin
Post by Mark Sims
I read that the latest GPS sats don't even have the ability to implement selective availability... seems a dubious claim to me, though.
---------------------
Post by Bob kb8tq
Indeed it might get turned back on again.
_______________________________________________
To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
and follow the instructions there.
_______________________________________________
time-nuts mailing list -- time-***@lists.febo.com
To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.c
John Reid
2018-09-08 05:05:10 UTC
Reply
Permalink
Raw Message
Hi all,


discussion of how to keep accurate time without access to GPS seems very
on topic to me.


These people involved in major catastrophe ('end of the world' as you
put it) scenarios have a wealth of experience in other ways of keeping
accurate time.


My 2c worth.


John
Message: 10
Date: Fri, 7 Sep 2018 20:31:32 -0400
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] Lost GPS lock or 1PPS recently?
Content-Type: text/plain; charset=utf-8
Hi
This is Time Nuts, not end of the world nuts ?..
<snip>
Bob
You are SO convinced that GPS will ALWAYS be there, I?m NOT (Think Carrington Event) and i?ve been part of a few disaster exercises where both Internet and GPS were considered ?down? for the exercise and these exercises are done in conjunction with the military so PPS was also ?off the table?.
<snip>

_______________________________________________
time-nuts mailing list -- time-***@lists.febo.com
To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
and follow the instructions there.
jimlux
2018-09-08 14:25:30 UTC
Reply
Permalink
Raw Message
Post by John Reid
Hi all,
discussion of how to keep accurate time without access to GPS seems very
on topic to me.
These people involved in major catastrophe ('end of the world' as you
put it) scenarios have a wealth of experience in other ways of keeping
accurate time.
Actually, they don't necessarily have a wealth of experience, because
they may have marched themselves down a path where they have a
*requirement* for much better timing than they realize, because it is so
easy and cheap to get good time today.

Imagine this scenario - you're a bank, and you batch process checks and
deposits in one physical location, so you don't much care about when the
check was written or the deposit made. Then you move to a distributed
system across the US, where the reconciliation is done on the basis of
the date of the transaction - still probably ok, because there are no
transactions during non-business hours, so as long as you reconcile at
1AM, if transaction time stamps are off by 5 minutes, it doesn't matter.


Now say "we're going to charge you, the customer a fee, if your balance
goes negative" and go to 24/7 operations, where transactions are
journaled immediately, rather than batch processed at night If a
deposit that was made at 12:00 (but timestamped 12:05) is followed by a
withdrawal made at 12:03 (but timestamped 12:00), you get unfairly
charged the overdraft fee.

For small problems, banks have ways to "unwind" errors. But if it
becomes a systemic thing that's a problem.

So the bank sets up GPSDOs at each transaction point - problem solved.

Until GPS fails.



_______________________________________________
time-nuts mailing list -- time-***@lists.febo.com
To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
and follow the instructions there.
Scott McGrath
2018-09-08 17:53:34 UTC
Reply
Permalink
Raw Message
This is precisely the scenario even a short GPS blackout of 1-2 weeks would cause. Its not that GPS is not the finest time transfer system ever devised. Its that with the loss of legacy systems we’ve lost the ability to degrade gracefully.

With a eLORAN system cell networks during a prolonged outage would probably degrade to 3G, but they would still be up. No you cant stream HD video or play GTA Online X, but talk,text email and Facebook would still work Time transfer for most applications would still work. The HFT boyos on Wall St would be SOL. Not sure how to evaluate that eventuality.


People like US need to educate political and business leadership on the need for BACKUPS to GPS mainly because things like the Carrington Event have happened before and WILL happen again.

And having terrestrial systems mean that you can get techs onsite to repair by horse if necessary unlike a space based system where some idiot retired the fleet of repair trucks. So the only remaining option is to launch new ones.
Post by John Reid
Hi all,
discussion of how to keep accurate time without access to GPS seems very
on topic to me.
These people involved in major catastrophe ('end of the world' as you
put it) scenarios have a wealth of experience in other ways of keeping
accurate time.
Actually, they don't necessarily have a wealth of experience, because they may have marched themselves down a path where they have a *requirement* for much better timing than they realize, because it is so easy and cheap to get good time today.

Imagine this scenario - you're a bank, and you batch process checks and deposits in one physical location, so you don't much care about when the check was written or the deposit made. Then you move to a distributed system across the US, where the reconciliation is done on the basis of the date of the transaction - still probably ok, because there are no transactions during non-business hours, so as long as you reconcile at 1AM, if transaction time stamps are off by 5 minutes, it doesn't matter.


Now say "we're going to charge you, the customer a fee, if your balance goes negative" and go to 24/7 operations, where transactions are journaled immediately, rather than batch processed at night If a deposit that was made at 12:00 (but timestamped 12:05) is followed by a withdrawal made at 12:03 (but timestamped 12:00), you get unfairly charged the overdraft fee.

For small problems, banks have ways to "unwind" errors. But if it becomes a systemic thing that's a problem.

So the bank sets up GPSDOs at each transaction point - problem solved.

Until GPS fails.



_______________________________________________
time-nuts mailing list -- time-***@lists.febo.com
To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
and follow the instructions there.

_______________________________________________
time-nuts mailing list -- time-***@lists.febo.com
To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.c
Bob kb8tq
2018-09-08 18:25:30 UTC
Reply
Permalink
Raw Message
Hi
Post by Scott McGrath
This is precisely the scenario even a short GPS blackout of 1-2 weeks would cause. Its not that GPS is not the finest time transfer system ever devised. Its that with the loss of legacy systems we’ve lost the ability to degrade gracefully.
How will the presence of a “backup” system that in no way at all interconnects with a cell tower have any
effect at all on it’s performance with loss of GPS ??? The legacy system (which does not even exist)
has *zero* impact in this case.
Post by Scott McGrath
With a eLORAN system cell networks during a prolonged outage would probably degrade to 3G,
Except that they have no way at all to do that. They simply are not designed that way and can not function
that way. The systems that *could* function at lower timing tolerance all got scrapped out long ago. That
of course *assumes* that eLoran can deliver < 100 ns timing. Is there any data to support that ?

Do any members have data on the 1 second timing out of eLoran? We’re about as deep into it as any
group not working for the eLoran people. If we haven’t seen any performance data …. I kinda doubt
anybody else has.
Post by Scott McGrath
but they would still be up. No you cant stream HD video or play GTA Online X, but talk,text email and Facebook would still work Time transfer for most applications would still work. The HFT boyos on Wall St would be SOL. Not sure how to evaluate that eventuality.
People like US need to educate political and business leadership on the need for BACKUPS to GPS
The reason the systems are designed just with GPS is *not* because “nobody mentioned the need
for a backup”. There are indeed people out there who spent a lot of time talking about this with the
guys who designed and spec’d these systems. The very simple answer *always* came back:

1) There is no alternative out there

2) There is not FCC requirement to do so = cost is not justified

3) There is absolutely zero demonstrated need

That’s very much three strikes you’re out.

Bob
Post by Scott McGrath
mainly because things like the Carrington Event have happened before and WILL happen again.
And having terrestrial systems mean that you can get techs onsite to repair by horse if necessary unlike a space based system where some idiot retired the fleet of repair trucks. So the only remaining option is to launch new ones.
Post by John Reid
Hi all,
discussion of how to keep accurate time without access to GPS seems very
on topic to me.
These people involved in major catastrophe ('end of the world' as you
put it) scenarios have a wealth of experience in other ways of keeping
accurate time.
Actually, they don't necessarily have a wealth of experience, because they may have marched themselves down a path where they have a *requirement* for much better timing than they realize, because it is so easy and cheap to get good time today.
Imagine this scenario - you're a bank, and you batch process checks and deposits in one physical location, so you don't much care about when the check was written or the deposit made. Then you move to a distributed system across the US, where the reconciliation is done on the basis of the date of the transaction - still probably ok, because there are no transactions during non-business hours, so as long as you reconcile at 1AM, if transaction time stamps are off by 5 minutes, it doesn't matter.
Now say "we're going to charge you, the customer a fee, if your balance goes negative" and go to 24/7 operations, where transactions are journaled immediately, rather than batch processed at night If a deposit that was made at 12:00 (but timestamped 12:05) is followed by a withdrawal made at 12:03 (but timestamped 12:00), you get unfairly charged the overdraft fee.
For small problems, banks have ways to "unwind" errors. But if it becomes a systemic thing that's a problem.
So the bank sets up GPSDOs at each transaction point - problem solved.
Until GPS fails.
_______________________________________________
To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
and follow the instructions there.
_______________________________________________
To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
and follow the instructions there.
_______________________________________________
time-nuts mailing list -- time-***@lists.febo.com
To unsubscribe, go to http://lists.febo.com/mailman/listinfo/tim
Didier Juges
2018-09-10 02:41:12 UTC
Reply
Permalink
Raw Message
Not a time-nut issue but most banks that batch process will process the
debits before the credit so that they get to charge you no matter what.
They probably don't all do it but some definitely do. I had one bank even
charge me multiple overdraft fees because they processed the largest checks
first, before the smaller ones in order to get my balance negative before
processing the smaller checks in order to maximize the fees. If the
transactions had been processed in the actual order, there would have been
no overdraft fee.
When I asked, they said the debits were processed electronically
(immediately) but the deposits (which I made by cash at the front desk)
were sent to a central office across the state BY MAIL for reconciliation,
and therefore processed (and credited to my account) several days later. I
did not remain a customer very long after that.
They closed in the 90s when it was revealed they were laundering money for
major drug traffickers.

But I see your point :)
Post by John Reid
Hi all,
discussion of how to keep accurate time without access to GPS seems very
on topic to me.
These people involved in major catastrophe ('end of the world' as you
put it) scenarios have a wealth of experience in other ways of keeping
accurate time.
Actually, they don't necessarily have a wealth of experience, because
they may have marched themselves down a path where they have a
*requirement* for much better timing than they realize, because it is so
easy and cheap to get good time today.

Imagine this scenario - you're a bank, and you batch process checks and
deposits in one physical location, so you don't much care about when the
check was written or the deposit made. Then you move to a distributed
system across the US, where the reconciliation is done on the basis of
the date of the transaction - still probably ok, because there are no
transactions during non-business hours, so as long as you reconcile at
1AM, if transaction time stamps are off by 5 minutes, it doesn't matter.


Now say "we're going to charge you, the customer a fee, if your balance
goes negative" and go to 24/7 operations, where transactions are
journaled immediately, rather than batch processed at night If a
deposit that was made at 12:00 (but timestamped 12:05) is followed by a
withdrawal made at 12:03 (but timestamped 12:00), you get unfairly
charged the overdraft fee.

For small problems, banks have ways to "unwind" errors. But if it
becomes a systemic thing that's a problem.

So the bank sets up GPSDOs at each transaction point - problem solved.

Until GPS fails.




_______________________________________________
time-nuts mailing list -- time-***@lists.febo.com
To unsubscribe, go to
http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
and follow the instructions there.
_______________________________________________
time-nuts mailing list -- time-***@lists.febo.com
To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
and follow the instructions there.

Loading...