Re: The GPS GR Correction, put to Rest.

From: Myxococcus xanthus (mold-guardian_NO_SPAM_at_comcast.net)
Date: 10/03/04 

Date: Sun, 03 Oct 2004 21:58:29 GMT

"Henri Wilson" <H@..> wrote in message
news:t4s0m05839u29jq7cqulgdufh6e1q6mvbc@4ax.com...
> On Sun, 3 Oct 2004 14:31:27 +0100, John Kennaugh
> <JKNG@kennaugh2435hex.freeserve.co.uk> wrote:
>
> >Randy Poe writes
> >>H@..(Henri Wilson) wrote in message
> >>news:<s4eml09b3qqahi7cjcpsiqc6jn5pqgsb8s@4ax.com>...
> >>> Myxo, you are such a hypocrite.
> >>> You have already assured me that the orbiting clocks are not altered
in any
> >>> way.
> >>
> >>You know that's not true. Everybody has told you, and you have agreed,
> >>that they are hardware altered to run at a different tick rate
> >>(on the ground) than their ground-station counterparts.
> >>
> >>What everyone also tells you is that there is no software rate
> >>control, as you keep pretending there is. There is no capability
> >>to change the tick rate once the satellites are launched, by
> >>software or otherwise.
> >
> >Speaking purely with my electronics consultant hat on, I would find that
> >quite incredible if true.
> >
> >If you have a clock - suppose it is a pendulum clock. You have two ways
> >of adjusting it.
> >
> >Method 1 you can listen to a time signal and set it correct to the time
> >signal (say) once a day. The problem with this method is that if it is
> >12 minutes out one day it will likely be 12 minutes the next etc. ad
> >infinitum.
> >
> >Method 2 is to find the error over 24 Hrs, reset it as method 1 but in
> >addition adjust the length of the pendulum to get rid of the predictable
> >10minute interval.
> >
> >Method 3 is to leave the pendulum as is but to predict that it
> >accumulates 0.5 min error every hour and to move the hands by half a
> >minute every hour.
> >
> >Now I don't know what oscillator is at the heart of a satellite but it
> >doesn't matter. As an engineer I can develop for example a crystal
> >oscillator and do as much as possible to select the most suitable cut of
> >crystal, have it pre aged, check that it will survive the launch
> >mechanically, compensate for temperature variation and circuit voltage
> >variations, and so on but at the end of the day if I was asked the
> >question - "can you guarantee that having been subjected to vibration
> >and G-forces on launch and subjected to temperature cycling every 24
> >hours and bombarded by radiation that it is going to give exactly the
> >same frequency over a 20 year period" I would say "no way but if you can
> >give it a time signal once a day I can compensate for the drift in
> >firmware as well as reset the time".
> >
> >Suppose the oscillator frequency is f and you are producing intervals of
> >n/f where n is the required nominal division from the basic oscillator.
> >You can make a large correction by changing the value of n but that
> >won't do. What is more likely is that you have it so that you can chose
> >between dividing by x which is very slightly less than n or x+1 very
> >slightly more. To get n exactly you might divide by x and x+1
> >alternatively dividing on average by x + 0.5 = n.
> >
> >In order to make a small adjustment i.e. correct errors before they
> >accumulate as per method 3' you can (say) make it divide by x+1 an extra
> >time every (say) y divisions.
> >
> >In principle the same sort of thing as adding a day to make a leap year
> >to synchronise the calendar. 365 is just less than the required n, 366
> >is a bit too much. There are other ways.
> >
> >It would be totally stupid to put something into orbit which is not self
> >adjusting. The bottom line is you cannot send a man up with a
> >screwdriver so you would be damn silly to send something into orbit with
> >no way of correcting for drift. If it drifts off you would have millions
> >of dollars worth of junk up there. Why would you not put in a micro
> >controller with the necessary firmware costing a couple of dollars?
>
> It is no good talking sense to them John.
>
> They WANT to believe the GPS clocks prove GR correct and nothing will sway
> them.
>
> They have all the religious faith and dedication required to become a
suicide
> bomber.
>
> Watch out!

I have been dealing with the FACTS about GPS here, not your stupid
imaginings nor John's idle speculations.

READ THE GPS ICD, both of you.

Myxococcus xanthus

Relevant Pages

  • Re: GPS GR Correction Myth.
    ... >> The first GPS satellite had the ability to turn on or off a hardware ... >> hardware or software adjustment made at the satellite after it is ... The receiver takes the actual clock reading and the correction ... The satellite clock is NOT changed. ...
    (sci.physics.relativity)
  • Re: oscillation stability
    ... You're experiencing one of the biggest limitations of this circuit. ... That means your frequency will temperature drift far ... Let's look first at what to do to to help your existing oscillator. ... Replace your cap with a ceramic NPO or other cap with a ...
    (sci.electronics.basics)
  • Re: Source of accurate frequency
    ... Most low cost digital crystal oscillator packages have 2 ... The other is temperature. ... manufacturing is 1/2 of the spec. ... GPS is a good straw man. ...
    (comp.arch.fpga)
  • Re: GPS Accuracy
    ... If others are going to use the information that you are compiling, those persons will undoubtedly have different GPS units and this will compound the problems that will affect the usefulness of your data. ... Then came the differential beacon that transmits local correction data to an auxiliary receiver that the GPS can use to correct the satellite data. ... Short term repeatability is the capability to indicate the location over an hour or so. ... The bottom line is that no consumer GPS is going to get you close enough to confirm that John's headstone is on Mary's grave, Fred's is on John's, and Mary's is on Fred's if those graves are close to each other. ...
    (rec.outdoors.rv-travel)
  • Re: GPS versus source dependency / ballistic theory
    ... >> That's the theoretical prediction. ... > correction in the clock frequencies. ... applied correction corresponds to the actual error. ... the remaining drift is less than 0.02 microsecond. ...
    (sci.physics)