Re: [time-nuts] GPS interference and history...
lists@rtty.us said:
There's an enormous amount of gear out there that gets timing off of GPS.
That's an interesting claim. Does anybody have any data on the usage of GPS
for timing?
I assume there is one in every cell tower and one in every 911 call center.
Are there other large categories of users?
What would it cost to replace all of it? If you wanted to do something like
that, what would "it" cover? How about people like us running old recycled
gear? (Z3801A, ThunderBolt, ...)
I think I saw one last week. It was on a river level measuring station on
the Sacramento River. It was a small block building. There was an antenna
pointing up into the sky. I assume there is a satellite up there. There was
also a small (~3 inch dia) hemisphere antenna. I assume it was GPS. (They
had power going into the building (no solar panels) so it should have been
simple to get a phone line too.)
I'm not sure why they need GPS at the recording house. They know where it is
so timing is the only use I can think of. But they could also get that at
the receiving end. Millisecond accuracy isn't helpful. Second level
accuracy might be interesting if something breaks and you want to know when
the wave got to downstream stations. The risetime is probably over a second.
--
These are my opinions, not necessarily my employer's. I hate spam.
Some other users of gps timing that I have noted thru observation or have personal knowledge of:
Timing for telecom providers (I have seen loran used in the past, but this option is more or less gone in North America now.)
Timing for power companies
Timing for industrial process control
Timing and frequency control for long range high performance microwave radio links
Timing and frequency control for private mobile radio systems
Timing for computer systems
Sent from my iPad
On 2011-06-10, at 7:01 PM, Hal Murray hmurray@megapathdsl.net wrote:
lists@rtty.us said:
There's an enormous amount of gear out there that gets timing off of GPS.
That's an interesting claim. Does anybody have any data on the usage of GPS
for timing?
I assume there is one in every cell tower and one in every 911 call center.
Are there other large categories of users?
What would it cost to replace all of it? If you wanted to do something like
that, what would "it" cover? How about people like us running old recycled
gear? (Z3801A, ThunderBolt, ...)
I think I saw one last week. It was on a river level measuring station on
the Sacramento River. It was a small block building. There was an antenna
pointing up into the sky. I assume there is a satellite up there. There was
also a small (~3 inch dia) hemisphere antenna. I assume it was GPS. (They
had power going into the building (no solar panels) so it should have been
simple to get a phone line too.)
I'm not sure why they need GPS at the recording house. They know where it is
so timing is the only use I can think of. But they could also get that at
the receiving end. Millisecond accuracy isn't helpful. Second level
accuracy might be interesting if something breaks and you want to know when
the wave got to downstream stations. The risetime is probably over a second.
--
These are my opinions, not necessarily my employer's. I hate spam.
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.
Maybe the site has other sensors, like seizmographs or groundwater level
that are not obvious.
-John
============
lists@rtty.us said:
There's an enormous amount of gear out there that gets timing off of
GPS.
That's an interesting claim. Does anybody have any data on the usage of
GPS
for timing?
I assume there is one in every cell tower and one in every 911 call
center.
Are there other large categories of users?
What would it cost to replace all of it? If you wanted to do something
like
that, what would "it" cover? How about people like us running old
recycled
gear? (Z3801A, ThunderBolt, ...)
I think I saw one last week. It was on a river level measuring station on
the Sacramento River. It was a small block building. There was an
antenna
pointing up into the sky. I assume there is a satellite up there. There
was
also a small (~3 inch dia) hemisphere antenna. I assume it was GPS. (They
had power going into the building (no solar panels) so it should have been
simple to get a phone line too.)
I'm not sure why they need GPS at the recording house. They know where it
is
so timing is the only use I can think of. But they could also get that at
the receiving end. Millisecond accuracy isn't helpful. Second level
accuracy might be interesting if something breaks and you want to know
when
the wave got to downstream stations. The risetime is probably over a
second.
--
These are my opinions, not necessarily my employer's. I hate spam.
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to
https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.
That small hemispherical antenna could also have been 900mhz. I have one here @ home that is a combined gps/900mhz antenna from an ambulance tracking system.
On Jun 10, 2011, at 22:01, Hal Murray hmurray@megapathdsl.net wrote:
lists@rtty.us said:
There's an enormous amount of gear out there that gets timing off of GPS.
That's an interesting claim. Does anybody have any data on the usage of GPS
for timing?
I assume there is one in every cell tower and one in every 911 call center.
Are there other large categories of users?
What would it cost to replace all of it? If you wanted to do something like
that, what would "it" cover? How about people like us running old recycled
gear? (Z3801A, ThunderBolt, ...)
I think I saw one last week. It was on a river level measuring station on
the Sacramento River. It was a small block building. There was an antenna
pointing up into the sky. I assume there is a satellite up there. There was
also a small (~3 inch dia) hemisphere antenna. I assume it was GPS. (They
had power going into the building (no solar panels) so it should have been
simple to get a phone line too.)
I'm not sure why they need GPS at the recording house. They know where it is
so timing is the only use I can think of. But they could also get that at
the receiving end. Millisecond accuracy isn't helpful. Second level
accuracy might be interesting if something breaks and you want to know when
the wave got to downstream stations. The risetime is probably over a second.
--
These are my opinions, not necessarily my employer's. I hate spam.
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.
The so called atomic clocks that used to be locked to WWVB have switched
over to GPs for higher reliability. My WWVB clocks loose lock when ever
there is a lightning storm within 50 miles but the GPS clocks stay locked.
No one is going to get hurt or killed because of a disabled GPS clock but
it's going to make a lot of people unhappy along with the manufacturers of
the clocks.
Regards.
Max. K 4 O D S.
Email: max@maxsmusicplace.com
Transistor site http://www.funwithtransistors.net
Vacuum tube site: http://www.funwithtubes.net
Music site: http://www.maxsmusicplace.com
To subscribe to the fun with transistors group send an email to.
funwithtransistors-subscribe@yahoogroups.com
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funwithtubes-subscribe@yahoogroups.com
----- Original Message -----
From: "Hal Murray" hmurray@megapathdsl.net
To: "Discussion of precise time and frequency measurement"
time-nuts@febo.com
Sent: Friday, June 10, 2011 9:01 PM
Subject: Re: [time-nuts] GPS interference and history...
lists@rtty.us said:
There's an enormous amount of gear out there that gets timing off of GPS.
That's an interesting claim. Does anybody have any data on the usage of
GPS
for timing?
I assume there is one in every cell tower and one in every 911 call
center.
Are there other large categories of users?
What would it cost to replace all of it? If you wanted to do something
like
that, what would "it" cover? How about people like us running old
recycled
gear? (Z3801A, ThunderBolt, ...)
I think I saw one last week. It was on a river level measuring station on
the Sacramento River. It was a small block building. There was an
antenna
pointing up into the sky. I assume there is a satellite up there. There
was
also a small (~3 inch dia) hemisphere antenna. I assume it was GPS. (They
had power going into the building (no solar panels) so it should have been
simple to get a phone line too.)
I'm not sure why they need GPS at the recording house. They know where it
is
so timing is the only use I can think of. But they could also get that at
the receiving end. Millisecond accuracy isn't helpful. Second level
accuracy might be interesting if something breaks and you want to know
when
the wave got to downstream stations. The risetime is probably over a
second.
--
These are my opinions, not necessarily my employer's. I hate spam.
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to
https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.
Hi
Best guess - a few million timing receivers are out there. Probably not over
ten million. To replace them at "new" prices, figure $5000 each including
the labor. Lots of variables, might be twenty billion dollars if you did a
straight swap.
Changing out antennas would be cheaper for the hardware and likely more for
the labor if a tower is involved. Might be half the price of doing the
receivers.
Quick math:
Take a tower count (say 250,000). Assume each system on the tower has doubly
redundant GPS. Take a reasonable number of systems per tower (at least 1
likely >4). That gets you to a million pretty quick. Add to that the
non-cell tower telcom stuff and you likely double or triple the number.
Bob
-----Original Message-----
From: Hal Murray
Sent: Friday, June 10, 2011 10:01 PM
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] GPS interference and history...
lists@rtty.us said:
There's an enormous amount of gear out there that gets timing off of GPS.
That's an interesting claim. Does anybody have any data on the usage of GPS
for timing?
I assume there is one in every cell tower and one in every 911 call center.
Are there other large categories of users?
What would it cost to replace all of it? If you wanted to do something like
that, what would "it" cover? How about people like us running old recycled
gear? (Z3801A, ThunderBolt, ...)
I think I saw one last week. It was on a river level measuring station on
the Sacramento River. It was a small block building. There was an antenna
pointing up into the sky. I assume there is a satellite up there. There
was
also a small (~3 inch dia) hemisphere antenna. I assume it was GPS. (They
had power going into the building (no solar panels) so it should have been
simple to get a phone line too.)
I'm not sure why they need GPS at the recording house. They know where it
is
so timing is the only use I can think of. But they could also get that at
the receiving end. Millisecond accuracy isn't helpful. Second level
accuracy might be interesting if something breaks and you want to know when
the wave got to downstream stations. The risetime is probably over a
second.
--
These are my opinions, not necessarily my employer's. I hate spam.
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to
https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.
On 6/10/11 7:01 PM, Hal Murray wrote:
lists@rtty.us said:
There's an enormous amount of gear out there that gets timing off of GPS.
That's an interesting claim. Does anybody have any data on the usage of GPS
for timing?
I assume there is one in every cell tower and one in every 911 call center.
Are there other large categories of users?
GPS timing antennas are sprouting like mushrooms in a lawn all over JPL.
(that's what they look like... you'll be walking around, and you'll
notice that there's 2 or 3 new stalks sticking up with a little antenna
on the top, and conduit running down the side of the building)
While we have masers and cesium sources at JPL, they're not distributed
everywhere. So, usually, the "easy" solution is to just get yourself a
Symmetricom or Fluke box, have facilities install the antenna, and your
lab is set.
I think I saw one last week. It was on a river level measuring station on
the Sacramento River. It was a small block building. There was an antenna
pointing up into the sky. I assume there is a satellite up there. There was
also a small (~3 inch dia) hemisphere antenna. I assume it was GPS. (They
had power going into the building (no solar panels) so it should have been
simple to get a phone line too.)
I'm not sure why they need GPS at the recording house. They know where it is
so timing is the only use I can think of. But they could also get that at
the receiving end. Millisecond accuracy isn't helpful. Second level
accuracy might be interesting if something breaks and you want to know when
the wave got to downstream stations. The risetime is probably over a second.
GPS is easy, that's why. It's under YOUR control. You spend a few
thousand bucks (including installation labor) and you have something
that works now and for the foreseeable future that you don't have to
worry about a comm line dropping, or resetting a clock or any of a
multitude of things.
Think about it.. what other totally off the shelf approach is there to
get time to 1 second accuracy over a span of years and temperatures that
does not require periodic "setting the clock"
bob-
you coming to greylock?
-Brian, WA1ZMS
On Jun 11, 2011, at 12:13 AM, bownes bownes@gmail.com wrote:
That small hemispherical antenna could also have been 900mhz. I have
one here @ home that is a combined gps/900mhz antenna from an
ambulance tracking system.
On Jun 10, 2011, at 22:01, Hal Murray hmurray@megapathdsl.net wrote:
lists@rtty.us said:
There's an enormous amount of gear out there that gets timing off
of GPS.
That's an interesting claim. Does anybody have any data on the
usage of GPS
for timing?
I assume there is one in every cell tower and one in every 911 call
center.
Are there other large categories of users?
What would it cost to replace all of it? If you wanted to do
something like
that, what would "it" cover? How about people like us running old
recycled
gear? (Z3801A, ThunderBolt, ...)
I think I saw one last week. It was on a river level measuring
station on
the Sacramento River. It was a small block building. There was an
antenna
pointing up into the sky. I assume there is a satellite up there.
There was
also a small (~3 inch dia) hemisphere antenna. I assume it was
GPS. (They
had power going into the building (no solar panels) so it should
have been
simple to get a phone line too.)
I'm not sure why they need GPS at the recording house. They know
where it is
so timing is the only use I can think of. But they could also get
that at
the receiving end. Millisecond accuracy isn't helpful. Second level
accuracy might be interesting if something breaks and you want to
know when
the wave got to downstream stations. The risetime is probably over
a second.
--
These are my opinions, not necessarily my employer's. I hate spam.
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.
Any enterprise large enough to have an IT deparment needs
precise timing. The cheapest stratum one source is GPS.
I work at a Research II university and have several in our network.
The time is the public key for our routers that send encrypted
routing table updates to each other.
There are several "mushrooms" over the EE wing of the College of
Engineering, and at least one over the ME neighborhood for some
laser measurement equipment...
One EE lab that is doing some GPS signal analysis has at least one
16 way splitter...
Jim Cotton
n8qoh
----- Original Message -----
From: "Jim Lux" jimlux@earthlink.net
To: time-nuts@febo.com
Sent: Saturday, June 11, 2011 10:08:18 AM
Subject: Re: [time-nuts] GPS interference and history...
On 6/10/11 7:01 PM, Hal Murray wrote:
lists@rtty.us said:
There's an enormous amount of gear out there that gets timing off
of GPS.
That's an interesting claim. Does anybody have any data on the usage
of GPS
for timing?
I assume there is one in every cell tower and one in every 911 call
center.
Are there other large categories of users?
GPS timing antennas are sprouting like mushrooms in a lawn all over
JPL.
(that's what they look like... you'll be walking around, and you'll
notice that there's 2 or 3 new stalks sticking up with a little
antenna
on the top, and conduit running down the side of the building)
While we have masers and cesium sources at JPL, they're not
distributed
everywhere. So, usually, the "easy" solution is to just get yourself a
Symmetricom or Fluke box, have facilities install the antenna, and
your
lab is set.
I think I saw one last week. It was on a river level measuring
station on
the Sacramento River. It was a small block building. There was an
antenna
pointing up into the sky. I assume there is a satellite up there.
There was
also a small (~3 inch dia) hemisphere antenna. I assume it was GPS.
(They
had power going into the building (no solar panels) so it should
have been
simple to get a phone line too.)
I'm not sure why they need GPS at the recording house. They know
where it is
so timing is the only use I can think of. But they could also get
that at
the receiving end. Millisecond accuracy isn't helpful. Second level
accuracy might be interesting if something breaks and you want to
know when
the wave got to downstream stations. The risetime is probably over a
second.
GPS is easy, that's why. It's under YOUR control. You spend a few
thousand bucks (including installation labor) and you have something
that works now and for the foreseeable future that you don't have to
worry about a comm line dropping, or resetting a clock or any of a
multitude of things.
Think about it.. what other totally off the shelf approach is there to
get time to 1 second accuracy over a span of years and temperatures
that
does not require periodic "setting the clock"
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to
https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.
I remember a professor at the University of Wisconsin Madison
who postulated the advancement of Man could be measured by
man's advancing technology of measuring time. We have come
a long way to get down to nanoseconds, LigutSquared notwithstanding.
I suppose the next advance will be to some soft of star date system.
--
Chuck Forsberg WA7KGX N2469R caf@omen.com www.omen.com
Developer of Industrial ZMODEM(Tm) for Embedded Applications
Omen Technology Inc "The High Reliability Software"
10255 NW Old Cornelius Pass Portland OR 97231 503-614-0430