SR/GR use absolute time to synchronize the GPS clocks with the ground clock.
in [Relativity]
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From: Sam Wormley on 26 Mar 2010 11:20 On 3/26/10 8:13 AM, kenseto wrote: > On Mar 24, 11:14 am, Sam Wormley<sworml...(a)gmail.com> wrote: >> On 3/24/10 8:27 AM, kenseto wrote: >> >>> Sigh...the discussion was about whether observed doppler shift will >>> effect the rate of a clock. The answer is no. The rate of a moving >>> clock is 1/gamma at all time. >> >>> Ken Seto >> >> Let the clock be a distant pulsar with radial velocity v with >> respect to the observer. The relativistic formula for the Doppler >> shift in pulse arrival time due to an arbitrary velocity is given >> by >> >> t' = (1 + v/c) γ t >> >> where v represents the velocity along the line of sight between >> source and observer and t' and t represent the time between >> pulses at the observer and at the source, respectively. > > Sigh....wormy t' is the cooridnate time. It tis not the rate of an > observed clock. The rate of an observed clock is 1/gamma at all times. > Why don't you study SR before you make a fool of yourself again. In the equation I posted, Seto, t' is the observed time between pulses of the distant pulsar. t' = (1 + v/c) γ t where v represents the velocity along the line of sight between source and observer and t' and t represent the time between pulses at the observer and at the source, respectively.
From: Michael Moroney on 26 Mar 2010 12:43 kenseto <kenseto(a)erinet.com> writes: >On Mar 24, 11:32 am, moro...(a)world.std.spaamtrap.com (Michael Moroney) >wrote: >> kenseto <kens...(a)erinet.com> writes: >> >On Mar 23, 12:51 pm, moro...(a)world.std.spaamtrap.com (Michael Moroney) >> >wrote: >> >> kenseto <kens...(a)erinet.com> writes: >> >> >Hey idiot time dilation got nothing to do with this discussion. >> >> >> Time dilation has *everything* to do with this discussion. Time dilation >> >> would cause the GPS satellite to "transmit" at the wrong frequency (as >> >> far as a terrestial receiver is concerned), so they adjusted the frequency >> >> before launch so it would at the correct frequency on Earth. >> >Sigh...the discussion was about whether observed doppler shift will >> >effect the rate of a clock. The answer is no. >> >> The discussion is about how different physical effects cause a frequency >> shift, and these frequency shifts can be calculated in advance and >> compensated for so that a relatively moving target receives a correct >> frequency. >No idiot...accoridng to SR the rate of a moving clock is always 1/ >gamma and it is independent of the direction of relative motion of the >observed source....in other words, observed doppler shift does not >effect the rate of a moving clcok. The redefined GPS second is make to >synchronize the GPS clock with the ground clock....IOW the passage of >one redefined GPS second will correspond to the passage of one ground >clock second. Are you really too stooopid to understand what's going on? Ground clock senses GPS clock as running too fast due to (mostly) GR effects. If it transmitted an "A" tune, it would be heard as a bit sharp. Designers know of this, can calculate the exact amount, and deliberately detune the clock (make it "flat" by the right amount) so the receiver receives the right tune. No "redefinition" of a second, as far as the GPS designer is concerned, instead of designing a satellite producing 1 pulse per second, for example, it produces 1 pulse per 1.0000000000001 seconds or something. In particular, the onboard frequency standard is 10.22999999543 MHz, which the ground receiver senses as running at 10.23 MHz. >You really need to study SR again before you make a fool of yourself >again. Speak for yourself. Obviously you have little comprehension of SR or GR.
From: Michael Moroney on 26 Mar 2010 12:57 kenseto <kenseto(a)erinet.com> writes: >On Mar 24, 12:02 pm, moro...(a)world.std.spaamtrap.com (Michael Moroney) >wrote: >> There are additional Doppler effects on the GPS signal as the satellites >> approach or recede, but I'm not talking about that. Don't try to confuse >> matters by mixing the Doppler of the GPS signals and the Doppler train >> example. >> >> Consider the signal from a satellite as it passes directly overhead, so >> that it is neither approaching nor receding. Doppler effect is zero. >> However since the satellite is not as deep in the earth's gravity well, >> there are GR effects. In addition the satellite is moving at a decent >> clip so that there are SR (NOT Doppler!) effects. With the cesium clock >> "mis-set" so that the divisor is N+4.15 periods of Cs, the received >> signal on earth's surface is absolutely correct. (remember, no Doppler >> in this case). >Sigh....the title of this thread is SR/GR uses abnsolute time to >synchronize the GPS clocks with the ground clock. Here you are talking >about the corrections to the data received from the GPS. I don't even mention data. It is nothing but a frequency. On board, the clock runs at 10.22999999543 MHz, the ground receiver sees it as 10.23 MHz. There is no such thing as "absolute time" just as there is no such thing as an absolute reference frame. How could there be? Consider a series of identical atomic clocks, one on the ground, the others in rockets directly over the ground clock at different altitudes and not moving relative to it (to eliminate Dopppler (and SR) effects). All of these clocks run at slightly different rates from each other, due to GR. Which one runs at "absolute time" and why?
From: kenseto on 26 Mar 2010 16:29 On Mar 26, 12:57 pm, moro...(a)world.std.spaamtrap.com (Michael Moroney) wrote: > kenseto <kens...(a)erinet.com> writes: > >On Mar 24, 12:02 pm, moro...(a)world.std.spaamtrap.com (Michael Moroney) > >wrote: > >> There are additional Doppler effects on the GPS signal as the satellites > >> approach or recede, but I'm not talking about that. Don't try to confuse > >> matters by mixing the Doppler of the GPS signals and the Doppler train > >> example. > > >> Consider the signal from a satellite as it passes directly overhead, so > >> that it is neither approaching nor receding. Doppler effect is zero.. > >> However since the satellite is not as deep in the earth's gravity well, > >> there are GR effects. In addition the satellite is moving at a decent > >> clip so that there are SR (NOT Doppler!) effects. With the cesium clock > >> "mis-set" so that the divisor is N+4.15 periods of Cs, the received > >> signal on earth's surface is absolutely correct. (remember, no Doppler > >> in this case). > >Sigh....the title of this thread is SR/GR uses abnsolute time to > >synchronize the GPS clocks with the ground clock. Here you are talking > >about the corrections to the data received from the GPS. > > I don't even mention data. It is nothing but a frequency. On board, the > clock runs at 10.22999999543 MHz, the ground receiver sees it as 10.23 MHz. > > There is no such thing as "absolute time" just as there is no such thing > as an absolute reference frame. How could there be? Consider a series of > identical atomic clocks, one on the ground, the others in rockets directly > over the ground clock at different altitudes and not moving relative to it > (to eliminate Dopppler (and SR) effects). All of these clocks run at > slightly different rates from each other, due to GR. Which one runs at > "absolute time" and why? Sigh......absolute time is the only time that exists. A clock second in the observer's frame represents a specific amount of absolute time. This amount of absolute time is represented by different clock readings on the observed clocks. Ken Seto
From: kenseto on 26 Mar 2010 16:41
On Mar 26, 12:43 pm, moro...(a)world.std.spaamtrap.com (Michael Moroney) wrote: > kenseto <kens...(a)erinet.com> writes: > >On Mar 24, 11:32 am, moro...(a)world.std.spaamtrap.com (Michael Moroney) > >wrote: > >> kenseto <kens...(a)erinet.com> writes: > >> >On Mar 23, 12:51 pm, moro...(a)world.std.spaamtrap.com (Michael Moroney) > >> >wrote: > >> >> kenseto <kens...(a)erinet.com> writes: > >> >> >Hey idiot time dilation got nothing to do with this discussion. > > >> >> Time dilation has *everything* to do with this discussion. Time dilation > >> >> would cause the GPS satellite to "transmit" at the wrong frequency (as > >> >> far as a terrestial receiver is concerned), so they adjusted the frequency > >> >> before launch so it would at the correct frequency on Earth. > >> >Sigh...the discussion was about whether observed doppler shift will > >> >effect the rate of a clock. The answer is no. > > >> The discussion is about how different physical effects cause a frequency > >> shift, and these frequency shifts can be calculated in advance and > >> compensated for so that a relatively moving target receives a correct > >> frequency. > >No idiot...accoridng to SR the rate of a moving clock is always 1/ > >gamma and it is independent of the direction of relative motion of the > >observed source....in other words, observed doppler shift does not > >effect the rate of a moving clcok. The redefined GPS second is make to > >synchronize the GPS clock with the ground clock....IOW the passage of > >one redefined GPS second will correspond to the passage of one ground > >clock second. > > Are you really too stooopid to understand what's going on? ROTFLOL....Pot calling the kettle black. > Ground clock senses GPS clock as running too fast due to (mostly) GR > effects. If it transmitted an "A" tune, it would be heard as a bit > sharp. Designers know of this, can calculate the exact amount, and > deliberately detune the clock (make it "flat" by the right amount) > so the receiver receives the right tune. No "redefinition" of a second, > as far as the GPS designer is concerned, instead of designing a satellite > producing 1 pulse per second, for example, it produces 1 pulse per > 1.0000000000001 seconds or something. Hey idiot....the GPS second is redefined have N+4.15 periods of Cs 133 radiation. This redefined GPS second contains the same amount of absolute time as a ground clock second which is represented by N periods of Cs 133 radiation. The reason why the GPS clock is in synch with the Ground clock at all time is because the rate of passage of absolute time is frame independent. ..Ken Seto > In particular, the onboard > frequency standard is 10.22999999543 MHz, which the ground receiver senses > as running at 10.23 MHz. > > >You really need to study SR again before you make a fool of yourself > >again. > > Speak for yourself. Obviously you have little comprehension of SR or GR.- Hide quoted text - > > - Show quoted text - |