The BIPM Circular-T would be a good place to start. 30s phase data used to
be available from each participating lab IIRC - they just updated their
webpages, so that may have been moved out of the public eye.
BR,
Ole
On Sat, Jul 17, 2021 at 9:17 PM Dwayne
wrote:
>Fellow Time-nuts;
>I am
Hi, All
I am trying to chase down a 2-3-4 ns/day "anomaly" in a gpsdo I am working
on - it could be temperature sensitivity in the antenna (cheap patch
jobbie), or I suspect my sealing of the outside connectors may not be
watertight. I just wanted to ask the list of anyone know of/has an estimate
Hi, All
I am going to give a presentation to non-nuts, and in one of the slides I
touch on Q - not wanting to spend more than a sentence or two on the
subject, I wonder if the following analogy works:
"A quality long-stemmed, thin-walled wine glass will ring for a long time
after we give it a
Better late than never! Happy H-Mas from EFOS-3 as well!
And a happy new year to all!
BR,
Ole
On Thu, Dec 24, 2020 at 6:48 PM Tom Van Baak wrote:
> You can see pendulum clocks swing and hear them tick. On the other hand,
> quartz, cesium, and GPS references are silent and invisible. It's Rb
Michael Wouters
wrote:
> Hello Ole
>
> Have you looked at dynamic Allan variance ? Patrizia Tavella wrote a few
> papers about this.
>
> Cheers
> Michael
>
> On Wed, 16 Sep 2020 at 7:28 pm, Ole Petter Ronningen <
> opronnin...@gmail.com>
> wrote:
>
> >
Just to add one datapoint to the discussion, I am presently looking at a
professional grade receiver ($20k+++), tracking GPS/GLONASS/GALIELO/BEIDOU,
44 sats total as I type this. It reports standard deviation of the XYZ
coordinates of 0.76m, 0.44m and 1.3m respectively. It is not crystal clear
how
> > Other time-nuts that have
> > been at IFCS/EFTF are Ole Petter Ronningen and Javier Serano.
> > Javier usually comes, when he has something to present and Ole if his
> > wife permits it ;-)
>
> Ole comes when I have tricked him to submit something... but now he
Precisely.
On Sun, Sep 15, 2019 at 6:03 PM Alberto di Bene wrote:
> On 2019-09-15 14:12, Forrest Christian (List Account) wrote:
>
> > Most GPS receivers with 1PPS outputs are only able to align the 1PPS to
> the
> > nearest edge of some internal clock. In addition, in most GPS
> receivers,
>
Asked and answered before I think, but as far as I know a new maser is in
the 2-300K euro range, a used one you can perhaps expect to pay about a
tenth of that - if you can find one. Not that many around, but some of the
older ones on VLBI sites are getting a bit long in the tooth. If you are
Just change the bottle, or hydride cartridge, whichever it is. But it is
also very possible that the ion pumps are at the end of their lives, but
these can also be replaced "easily". What type if maser is it?
Ole
On Fri, Jul 5, 2019 at 7:01 PM Luiz Paulo Damaceno <
luizpauloeletric...@gmail.com>
Hi, Dana
My understanding is that all criteria should be met, but the list might be
refined. Dr. Martin Milton, Director of the BIPM gave a talk on the subject
on this years IFCS/EFTF; https://www.youtube.com/watch?v=Qsgl8AHBU7c
(redefinition
of the second at around 33 minutes, but the whole talk
Hi, all
I just stumbled across a nice review paper from last year: (
https://arxiv.org/ftp/arxiv/papers/1803/1803.01585.pdf) that perhaps others
will find interesting.
Primarily geared towards geodesy as the title indicates, but it also looks
at several techniques of interest to time-nuts, such
PPP works on observations - i.e. pseudorange and accumulated doppler range
from the antenna to the satellites - it does not know or care what
position the reciever thinks it is at, so that makes sense.
Ole
On Sun, Apr 7, 2019 at 8:02 PM John Ackermann N8UR wrote:
> I got the NRCan results
this list.
>
> On 10/26/18 11:34 AM, Ole Petter Ronningen wrote:
> > Hi, all
> >
> > I'm simulating some noise to try to improve my somewhat sketchy
> > understanding of what goes on with the various noise types as shown on an
> > ADEV plot. Nothing fancy, ~
Hi, Tom!
I have looked at the pages you link to many times, they really are very
good - my goal here was to get down to the nitty-gritty myself, just
understand the details better.
Regarding possible bias in the Excel RNG, this was my first hunch as well,
but when I repeated the experiment with
Hi, Attila
> I see two issues here: If your random numbers are indeed between 0 and 1,
> as you write, then they are uniformly distributed, and not normally
> distributed. This will give you a slight bias when integrating.
>
You are correct, my statement was imprecise - I generate numbers
Hi, all
I'm simulating some noise to try to improve my somewhat sketchy
understanding of what goes on with the various noise types as shown on an
ADEV plot. Nothing fancy, ~3600 points of gaussian random numbers between 0
and 1 in excel, imported into Timelab as phase data, scaled to ns.
I
On Thu, Oct 4, 2018 at 1:40 PM Magnus Danielson
wrote:
> Who-oh! OK. This means that one should intentionally let a number of
> samples pass before trusting it.
>
Precisely. But, crucially, discard 1-2 samples *since the last INIT* -
which may not be obvious without some investigation. It is a
On Thu, Oct 4, 2018 at 11:00 AM Magnus Danielson
wrote:
> Regardless, the 53230A does a filtered frequency estimation, which is
> great for achieving high precision frequency measures quickly, but not
> good for ADEV measures, as it introduces a bias due to the lower
> bandwidth of the filtering
Somewhat longer answer; I assume you have set up a frequency measurement
(as opposed to time interval)
1. Timelab uses SCPI-command "READ" to fetch readings from the 53230a (and
most other counters *). The 53230a does not return gap free frequency
measurements in this case. There will be deadtime
Corby,
When you write "I.F. Level", I assume you mean the 5.7KHz going to the PLL
- or are you monitoring some other signal?
Re LO; I would expect any issue with the LO would be directly observable on
the output from the Maser - only an isolation amp in between. Have you
measured the EFC on the
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