Am 01.09.2018 um 20:40 schrieb Magnus Danielson:
One should first know that there is a lot of papers now on frequency
transfer over fiber. The stability achieved on the best ones so far
greatly below that of the optical clocks that they want to compare.
Please, in a nutshell: what are the
Hi Bob,
Thanks for the paper.
One should first know that there is a lot of papers now on frequency
transfer over fiber. The stability achieved on the best ones so far
greatly below that of the optical clocks that they want to compare.
Then, for those links able to transfer phase/time, most of
There was a paper published when NASA did something similar for LC39 and the
VAB.Anyone have a copy because the link i have is dead.
As I recall it was some trick and compensating for thermal effects on the fiber
itself was a large part of the effort.
On Sep 1, 2018, at 5:29 AM, Magnus
Hi,
It was very telling when I crashed a research group into the reality of
phase/time transfer over fiber compared to frequency transfer. Armed
with a whiteboard and pens, I derived the forumulas and showed how they
worked and not worked. It's a completely different ball-game and their
"known
al Message-
> From: time-nuts On Behalf Of Bob kb8tq
> Sent: Friday, August 31, 2018 11:16 AM
> To: Martin VE3OAT ; Discussion of precise time and frequency
> measurement
> Subject: Re: [time-nuts] WWV and legal issues
>
> Hi
>
> That works fine if you are doing
: time-nuts On Behalf Of Bob kb8tq
Sent: Friday, August 31, 2018 11:16 AM
To: Martin VE3OAT ; Discussion of precise time and frequency
measurement
Subject: Re: [time-nuts] WWV and legal issues
Hi
That works fine if you are doing things manual to check a local standard. If
you are trying
; Discussion of precise time and frequency
measurement
Subject: Re: [time-nuts] WWV and legal issues
Hi
That works fine if you are doing things manual to check a local standard. If
you are trying to
disipline a few thousand cell towers 24 hours a day … not so much. It also
works
Hi
That works fine if you are doing things manual to check a local standard. If
you are trying to
disipline a few thousand cell towers 24 hours a day … not so much. It also
works for
checking frequency. What modern systems need is time. That gets you into a
whole
world of resolving and
Hi
Same basic problem with WWVB. If you were using it as a reference, you timed
your
data collection to avoid the transition periods. You got both phase shifting
and the
amplitude took a dive. Neither one was going to help you make a precision
measurement.
In addition there are various
>> WWVB goes off the air what is the replacement for the 60KHz standard?
>>
>> Mike
>>
>> -Original Message-
>> From: time-nuts [mailto:time-nuts-boun...@lists.febo.com] On Behalf Of Perry
>> Sandeen via time-nuts
>> Sent: Wednesday, Augus
at is the replacement for the 60KHz standard?
>
> Mike
>
> -Original Message-
> From: time-nuts [mailto:time-nuts-boun...@lists.febo.com] On Behalf Of Perry
> Sandeen via time-nuts
> Sent: Wednesday, August 29, 2018 6:34 PM
> To: time-nuts@lists.febo.com
> Cc: Pe
or the 60KHz standard?
>
> Mike
>
> -Original Message-
> From: time-nuts [mailto:time-nuts-boun...@lists.febo.com] On Behalf Of Perry
> Sandeen via time-nuts
> Sent: Wednesday, August 29, 2018 6:34 PM
> To: time-nuts@lists.febo.com
> Cc: Perry Sandeen
> Subj
ecise time and frequency measurement
Subject: Re: [time-nuts] WWV and legal issues
Bingo - we have a a Winner!!!
In a prior life as an architect at a northeastern we had Cs clocks, multiple
GPS based NTP servers and CDMA NTP servers as TIME was the public key for all
the crypto systems the Cs c
-nuts] WWV and legal issues
Um no
Will the internet continue to route packets without precision timing yes it
will, Yes the lambdas will stay lit on fiber but the ATM transport that runs
on the lambdas will fail (note DSL is simply an ATM VC over copper). and other
timing dependent services
Hi
This is not so much a GPS issue as a system design issue. GPSDO’s are used to
“smooth over” bumps in a lot
of systems out there. At the timing levels required by ATM or authentication
setups, you can go a *long* time
running on a GPSDO. It’s not a matter of GPS, it’s a matter of doing
of precise time and frequency measurement
Subject: Re: [time-nuts] WWV and legal issues
Um no
Will the internet continue to route packets without precision timing yes it
will, Yes the lambdas will stay lit on fiber but the ATM transport that runs
on the lambdas will fail (note DSL is simply an ATM VC
On Thu, Aug 30, 2018 at 9:42 AM, Scott McGrath wrote:
> Um no
>
> Will the internet continue to route packets without precision timing yes
> it will, Yes the lambdas will stay lit on fiber but the ATM transport that
> runs on the lambdas will fail (note DSL is simply an ATM VC over copper).
>
Um no
Will the internet continue to route packets without precision timing yes it
will, Yes the lambdas will stay lit on fiber but the ATM transport that runs
on the lambdas will fail (note DSL is simply an ATM VC over copper). and other
timing dependent services will fail
Will many
Hi
One of the basic disconnects here seems to be the idea that radio was the “best
thing” before
GPS came along. In fact that’s not really how it worked. Time was traced /
coordinated by hauling
atomic clocks on airplanes as the “best thing” before satellite systems came
along….That was true
Hi
The same sort of massive solar flare that fiddles with sat systems also makes a
mess of HF and VLF
systems. You have a high level of correlation in the impact. That makes them a
poor “backup” in this case.
Bob
> On Aug 29, 2018, at 7:52 PM, Scott McGrath wrote:
>
> Excellent point on
A DIY radio distribution system is not secure and traceable to NIST/USNO even
if the source is GPS.
On Aug 29, 2018, at 7:52 PM, Scott McGrath wrote:
Excellent point on LEGAL time, The problem is as always is GPS is the new
shiny object.
You mentioned earth based hostile actors. But a
Excellent point on LEGAL time, The problem is as always is GPS is the new
shiny object.
You mentioned earth based hostile actors. But a really large solar flare or
CME has the potential to take out or severely degrade ALL the GNSS systems.
Something on the order of the ‘Carrington Event’
Yo Dudes!
WWV and all its variations distribute what in the USA is the legal standard of
time (from USNO) and frequency (NIST).
If one is running a freq cal service IIRC it is a legal requirement to be able
to have traceability to WWV.
If one was to rely on other sources, one has no guarantee
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