Re: [time-nuts] Q/noise of Earth as an oscillator

I still claim that there is no natural frequency associated with the rotation of a body. The periodic nature of the rotating body motion is confusing you. The choice of a coordinate system is what is confusing. As I pointed out, what's the difference between an inertial body moving in a straight

Re: [time-nuts] Q/noise of Earth as an oscillator

On Sat, Jul 30, 2016 at 1:19 AM, Tom Van Baak wrote: > The remaining question in this thread is if earth Q measurement has actual > meaning, that is, if the concept of Q is valid for a slowly decaying rotating > object, as it is for a slowly decaying simple harmonic oscillator. And that's >

Re: [time-nuts] Commercial software defined radio for clockmetrology

Hi Kevin, Sorry for jumping into the thread somewhat late, but I am away on a music festival, spending my vacation working. I think some of what I would like to point out has already been covered, somewhat indirectly. When you measure ADEV, white phase modulation and flicker phase

Re: [time-nuts] Q/noise of Earth as an oscillator

Hi Tom, You said: "you need energy; you need energy loss; you need cycles over which that loss repeatedly occurs." With regard to the earth, where is the first one? Sure it was there at the start when the solar system formed, but where is it now? Jim On 1 August 2016 at 12:16, Tom Van Baak

Re: [time-nuts] Commercial software defined radio for clockmetrology

Hi Tom, Thanks for your thoughts. I had looked at your helpful page when I started researching the effects of averaging. Currently, I’m experimenting with the dual receivers in the SDR using cross-correlation to reduce the noise floor. Kevin > On Jul 30, 2016, at 5:08 PM, Tom Van Baak

[time-nuts] Another arrival time histogram: SiRF III

It was setup to only send GPRMC sentences. http://users.megapathdsl.net/~hmurray/time-nuts/RMC-hist.png Here is what it looks like over time: http://users.megapathdsl.net/~hmurray/time-nuts/RMC-offset.png There are interesting glitches at 3 hours and 23 hours. Anybody have any ideas about

Re: [time-nuts] Q/noise of Earth as an oscillator

t...@radio.sent.com said: > As I pointed out, what's the difference between an inertial body moving in a > straight line and a rotating body? The rotating body has a natural unit of time so there is a convenient way to make Q dimensionless. For linear motion, the natural unit of decay would be

Re: [time-nuts] Q/noise of Earth as an oscillator

At the risk of boring everyone, here is an "Alice and Bob" thought experiment concerning linear and circular movement: Condition A: Let's say that Alice is in her spacecraft in inertial straight line travel through nearly free space containing a thin gas which creates a slight friction to

Re: [time-nuts] Q/noise of Earth as an oscillator

Hal: > Is there a term other than Q that is used to describe the rate of energy loss > for things that aren't oscillators? Jim: > cooling (as in hot things) > discharge (as in capacitors and batteries) > leakage (as in pressure vessels) > loss Scott: > An irreversible process would be a better

Re: [time-nuts] Adafruit Ultimate GPS timing message arrival times

From: Mark Sims A couple of people have asked about the poor message arrival time performance of the popular Adafruit Ultimate GPS receiver. I modified Lady Heather to analyze the message arrival times using a histogram instead of a simple average. When I looked at the histogram data (.01

Re: [time-nuts] Short-term frequency stability symposium 1964

That NASA SP-80 is a classic! Your upload looks like the 17.5 MB version at: https://archive.org/details/nasa_techdoc_19660001092 There's also a (cleaner?) 9.7 MB copy here: http://www.ieee-uffc.org/main/history/short-term_f_stab.pdf which is part of the excellent collection of historical

[time-nuts] GPSDO design articles

Finally for today, I posted two white papers from PTF, Inc. that discuss the basics of GPSDO design. These are the best accessible discussions of "how it's done" at the professional level that I'm aware of, and (IMO) should be required reading for anyone attempting a DIY GPSDO design. Note

Re: [time-nuts] Short-term frequency stability symposium 1964

On 7/31/16 3:40 AM, Charles Steinmetz wrote: I was looking through my files and found a 1965 NASA publication that contains the papers presented at a 1964 IEEE-NASA symposium on the short-term stability of oscillators. It's a wonderful collection of seminal papers by most of the usual suspects

[time-nuts] Adafruit Ultimate GPS timing message arrival times

As mentioned in the post the times reported are the time stamp in the receiver packet minus the system clock time when it was received... negative value indicate the message arrives after the PPS. The polarity of the reported value is consistent with how Lady Heather makes use of the

[time-nuts] Diophantine frequency synthesis articles

I also posted six files pertaining to Diophantine frequency synthesis on Didier's site. Four are papers dating to 2006-2007 by Sotiriadis, one is a paper of the same era by Stork, and one is a patent granted to Wilke in 1993. These are also still in quarantine, but will be searchable when

Re: [time-nuts] Q/noise of Earth as an oscillator

I agree with those who repudiate the use of "Q" with respect to the length of an Earth day, and I feel that the statement about the Earth near the end of "The Story of Q" is incorrect when viewed from a modern perspective. I base my arguments on: (1) The existing use of Q to describe the tidal

Re: [time-nuts] Q/noise of Earth as an oscillator

Ron Ott wrote: > There might be two Qs: one relating to the axil rotation and another > concerning the volume behavior Hi Ron, Chris, and now also Bill, I was thinking this tangent wouldn't come up, but yes, in the fields of Seismology or Earth Science, you will also see "quality factor" and

Re: [time-nuts] Q/noise of Earth as an oscillator

t...@radio.sent.com said: > So loss effects frequency in one situation and amplitude in the other. How > can Q relate to both situations? It's energy loss in both cases. Is there a term other than Q that is used to describe the rate of energy loss for things that aren't oscillators? --

Re: [time-nuts] Q/noise of Earth as an oscillator

On 7/31/16 5:19 PM, Hal Murray wrote: t...@radio.sent.com said: So loss effects frequency in one situation and amplitude in the other. How can Q relate to both situations? It's energy loss in both cases. Is there a term other than Q that is used to describe the rate of energy loss for

Re: [time-nuts] Q/noise of Earth as an oscillator

An irreversible process would be a better description versus energy loss. Like joule heating (resistance, friction). On Sunday, 31 July 2016, Hal Murray wrote: > > t...@radio.sent.com said: > > So loss effects frequency in one situation and amplitude in

Re: [time-nuts] Q/noise of Earth as an oscillator

Hi > On Jul 31, 2016, at 8:19 PM, Hal Murray wrote: > > > t...@radio.sent.com said: >> So loss effects frequency in one situation and amplitude in the other. How >> can Q relate to both situations? > > It's energy loss in both cases. > > Is there a term other than Q

Re: [time-nuts] Q/noise of Earth as an oscillator

Hal Murray wrote: > It's energy loss in both cases. > > Is there a term other than Q that is used to describe the rate of energy loss > for things that aren't oscillators? I've seen "energy dissipation" or "energy decrement". Before Q was used to describe line width of atomic and optical