GPS and SR. Do they really constitute a 'proof'?

[RLH]

The problems with translating theory into practice often eludes people.

Things are not so simple as first conceived.

1. The actual velocity that a ground station sees the various satellites is not just pure orbital mechanics. There is an offset for drag for a start. And one for gravitational anomalies.

2. The passage of time for the signals from the satellites to the ground station is one of, a very thin gas to quite a thick gas. This can be minimised by considering that all signals from the satellites used are traveling though a homogeneous gas structure. This is most certainly not true for water vapour as many have found out.

3. The clocks are reset quite frequently. Thus removing the ability to do long time series checks/verification.

4. The above terms dominate any calculations. Any 'corrections' for SR are usually down in the dust, comparatively speaking.

So do GPS satellites 'prove' SR, well maybe, maybe not. It depends on how closely you look (or not).

[Poutnik]

Dne 19.10.2017 v 16:15 RLH napsal(a):

There is no such thing as experimental proof of physical theory.
Theory predictions are confirmed or refuted.

The first your mistake is to relate SR and GPS.

The second your mistake
is trying to outperform the scientists and engineers,
supposing they omitted details,
without verification if they really did so.



--
Poutnik ( The Pilgrim, Der Wanderer )

A wise man guards words he says,
as they say about him more,
than he says about the subject.

[Dono,]

On Thursday, October 19, 2017 at 7:15:05 AM UTC-7, RLH wrote:
>
> So do GPS satellites 'prove' SR, well maybe, maybe not. It depends on how closely you look (or not).

GPS and a slew of experiments CONFIRM GR. There is no such thing as "proving" in physics.

[Thomas 'PointedEars' Lahn]

Poutnik wrote:

> Dne 19.10.2017 v 16:15 RLH napsal(a):

>> [not even wrong]

>> So do GPS satellites 'prove' SR, well maybe, maybe not. It depends on how
>> closely you look (or not).
>
> There is no such thing as experimental proof of physical theory.
> Theory predictions are confirmed or refuted.

ACK.

> The first your mistake is to relate SR and GPS.

No, *that* is _not_ one of the many mistakes he made here. GPS actually
depends on that SR is correct, IOW it confirms SR:

<https://en.wikipedia.org/wiki/Global_Positioning_System#Navigation_equations>

(But that is not the whole picture.)


PointedEars
--
Q: What did the nuclear physicist post on the laboratory door
when he went camping?
A: 'Gone fission'.
(from: WolframAlpha)

[Poutnik]

Dne 19.10.2017 v 17:28 Thomas 'PointedEars' Lahn napsal(a):

> Poutnik wrote:
>
>> Dne 19.10.2017 v 16:15 RLH napsal(a):
>>> [not even wrong]
>>> So do GPS satellites 'prove' SR, well maybe, maybe not. It depends on how
>>> closely you look (or not).
>>
>> There is no such thing as experimental proof of physical theory.
>> Theory predictions are confirmed or refuted.
>
> ACK.
>
>> The first your mistake is to relate SR and GPS.
>
> No, *that* is _not_ one of the many mistakes he made here. GPS actually
> depends on that SR is correct, IOW it confirms SR:
>
> <https://en.wikipedia.org/wiki/Global_Positioning_System#Navigation_equations>

I had in mind that GPS depends on GR being correct
that depends on SR being correct.

SR being correct alone is not sufficient for GPS.

By other words, SR being correct
is the mandatory, but not sufficient condition for GPS.

[Thomas 'PointedEars' Lahn]

Poutnik wrote:
^^^^^^^
It is considered polite to post using your real name here.

> Dne 19.10.2017 v 17:28 Thomas 'PointedEars' Lahn napsal(a):
>> Poutnik wrote:
>>> The first your mistake is to relate SR and GPS.
>>
>> No, *that* is _not_ one of the many mistakes he made here. GPS actually
>> depends on that SR is correct, IOW it confirms SR:
>>
>>
<https://en.wikipedia.org/wiki/Global_Positioning_System#Navigation_equations>
>
> I had in mind that GPS depends on GR being correct
> that depends on SR being correct.
>
> SR being correct alone is not sufficient for GPS.
>
> By other words, SR being correct
> is the mandatory, but not sufficient condition for GPS.

Correct. AISB.


PointedEars
--
Q: Who's on the case when the electricity goes out?
A: Sherlock Ohms.

(from: WolframAlpha)

[RLH]

On Thursday, October 19, 2017 at 4:42:34 PM UTC+1, Poutnik wrote:
> Dne 19.10.2017 v 17:28 Thomas 'PointedEars' Lahn napsal(a):
> > Poutnik wrote:
> >
> >> Dne 19.10.2017 v 16:15 RLH napsal(a):
> >>> [not even wrong]
> >>> So do GPS satellites 'prove' SR, well maybe, maybe not. It depends on how
> >>> closely you look (or not).
> >>
> >> There is no such thing as experimental proof of physical theory.
> >> Theory predictions are confirmed or refuted.
> >
> > ACK.
> >
> >> The first your mistake is to relate SR and GPS.
> >
> > No, *that* is _not_ one of the many mistakes he made here. GPS actually
> > depends on that SR is correct, IOW it confirms SR:
> >
> > <https://en.wikipedia.org/wiki/Global_Positioning_System#Navigation_equations>
>
> I had in mind that GPS depends on GR being correct
> that depends on SR being correct.
>
> SR being correct alone is not sufficient for GPS.
>
> By other words, SR being correct
> is the mandatory, but not sufficient condition for GPS.

Possibly true. The problem is that, as I know from personal experience, the calculations are dominated by many, many, factors other than SR/GR.

Mobile computing GPS (include Satnav and phones) can be quite tricky to get right. The signals are usually converted to position by working out using a map and roads, etc. to get the 'right' position or by multiple samples over time at a single position to average out the errors that occur or by using a local, fixed GPS reference so that you are only looking at differentials between a local A and B.

Definitely not as simple as it looks.

From the Wiki

"GPS error analysis examines error sources in GPS results and the expected size of those errors. GPS makes corrections for receiver clock errors and other effects, but some residual errors remain uncorrected. Error sources include signal arrival time measurements, numerical calculations, atmospheric effects (ionospheric/tropospheric delays), ephemeris and clock data, multipath signals, and natural and artificial interference. Magnitude of residual errors from these sources depends on geometric dilution of precision. Artificial errors may result from jamming devices and threaten ships and aircraft[126] or from intentional signal degradation through selective availability, which limited accuracy to ≈6–12 m, but has been switched off since May 1, 2000"

[RLH]

Semantics. Confirm = proof/success. Refute = failure.

Learn to do the conversions in your head. Otherwise you look like someone who cannot converse, only argue.

Ever thought that I might be using the term to distinguish between those who think and converse to those who quote or attack.

In engineering we 'prove' by success or failure. We do not Refute or Confirm.

[RLH]

On Thursday, October 19, 2017 at 3:27:58 PM UTC+1, Poutnik wrote:
> There is no such thing as experimental proof of physical theory.
> Theory predictions are confirmed or refuted.

OK. Semantics. Does GPS confirm or refute SR.

> The first your mistake is to relate SR and GPS.

Why? Everybody quotes it as a 'proof' all the time(pun).

> The second your mistake
> is trying to outperform the scientists and engineers,
> supposing they omitted details,
> without verification if they really did so.

I was pointing that engineers often have a different view to scientists. Things have to actually work otherwise they are useless.

So do you think that engineers took into account the above. Certainly they did.

The question is, do those terms dominate the calculations or not?

[Libor 'Poutnik' Striz]

Dne 19.10.2017 v 17:59 RLH napsal(a):

>
> Possibly true. The problem is that, as I know from personal experience, the calculations are dominated by many, many, factors other than SR/GR.
>
> Mobile computing GPS (include Satnav and phones) can be quite tricky to get right. The signals are usually converted to position by working out using a map and roads, etc. to get the 'right' position or by multiple samples over time at a single position to average out the errors that occur or by using a local, fixed GPS reference so that you are only looking at differentials between a local A and B.
>
> Definitely not as simple as it looks.
>
> From the Wiki
>
> "GPS error analysis examines error sources in GPS results and the expected size of those errors. GPS makes corrections for receiver clock errors and other effects, but some residual errors remain uncorrected. Error sources include signal arrival time measurements, numerical calculations, atmospheric effects (ionospheric/tropospheric delays), ephemeris and clock data, multipath signals, and natural and artificial interference. Magnitude of residual errors from these sources depends on geometric dilution of precision. Artificial errors may result from jamming devices and threaten ships and aircraft[126] or from intentional signal degradation through selective availability, which limited accuracy to ≈6–12 m, but has been switched off since May 1, 2000"

So what ?
GPS system is well aware of that.
Not all in GPS is about exact atomic time.

[Libor 'Poutnik' Striz]

Dne 19.10.2017 v 17:59 RLH napsal(a):

> On Thursday, October 19, 2017 at 3:27:58 PM UTC+1, Poutnik wrote:
>> There is no such thing as experimental proof of physical theory.
>> Theory predictions are confirmed or refuted.
>
> OK. Semantics. Does GPS confirm or refute SR.

GPS confirm SR and GR.
Rather, validity of GR allows building of working GPS,
otherwise much more frequent empirical corrections
would have to be made.

>
>> The first your mistake is to relate SR and GPS.
>
> Why? Everybody quotes it as a 'proof' all the time(pun).

Everybody ?

>> The second your mistake
>> is trying to outperform the scientists and engineers,
>> supposing they omitted details,
>> without verification if they really did so.
>
> I was pointing that engineers often have a different view to scientists. Things have to actually work otherwise they are useless.
> So do you think that engineers took into account the above. Certainly they did.

Military engineers refused to use GR corrections of satellite atomic
clocks. Fortunately, the correction ON/OFF remote switching was
implemented, and they gladly turned corrections ON,
realizing the GPS does not work well without them.

>
> The question is, do those terms dominate the calculations or not?

This question and answer to it belongs to basic knowledge
as prerequisite to talk about that.
Discussion is very inferior way to gain it.

GR correction of clocks is 38 microseconds per day.
All other corrections are very minor wrt this.

[RLH]

You don't say! And then you ignore it all to 'prove' SR/GR.

[Libor 'Poutnik' Stříž]

Dne 19.10.2017 v 18:19 RLH napsal(a):

You do not know what you talk about.
BTW, What have I recently said about proofs of physical theories ?

[RLH]

The satellite clocks are reset, usually at less than 24 hour periods.

Care to ranges to the factors detailed below/above? To compare to the 38ms that is.

"GPS error analysis examines error sources in GPS results and the expected size of those errors. GPS makes corrections for receiver clock errors and other effects, but some residual errors remain uncorrected. Error sources include signal arrival time measurements, numerical calculations, atmospheric effects (ionospheric/tropospheric delays), ephemeris and clock data, multipath signals, and natural and artificial interference. Magnitude of residual errors from these sources depends on geometric dilution of precision. Artificial errors may result from jamming devices and threaten ships and aircraft[126] or from intentional signal degradation through selective availability, which limited accuracy to ≈6–12 m, but has been switched off since May 1, 2000"

Also

"Synchronization to GPS
GPS satellites (and now other global navigation systems commonly referred to as GNSS) include three or four atomic clocks that are monitored and controlled to be highly synchronized and traceable to national and international standards (known as UTC). So for time synchronization, the GPS signal is received, processed by a local master clock, time server, or primary reference, and passed on to "slaves" and other devices, systems, or networks so their "local clocks" are likewise synchronized to UTC. Typical accuracies range from better than 1 microsecond to a few milliseconds depending on the synchronization protocol. It is the process of synchronization to GPS that can provide atomic clock accuracy without the need for a local atomic clock. Still, local atomic clocks are sometimes desired as a long-term back-up solution to loss-of-GPS, either in the case or a weather-related outage, GPS interference, or other scenarios.

In any case, GPS clock synchronization eliminates the need for manual clock setting (an error-prone process) to establish traceability to national and international standards so various events can be correlated even when they are time-stamped by different clocks. The benefits are numerous and include: legally validated time stamps, regulatory compliance, secure networking, and operational efficiency."

[RLH]

I forgot

"Because an observer on the ground sees the satellites in motion relative to them, Special Relativity predicts that we should see their clocks ticking more slowly (see the Special Relativity lecture). Special Relativity predicts that the on-board atomic clocks on the satellites should fall behind clocks on the ground by about 7 microseconds per day because of the slower ticking rate due to the time dilation effect of their relative motion [2]."

"GR correction of clocks is 38 microseconds per day.
All other corrections are very minor wrt this."

Wrong.

[RLH]

On Thursday, October 19, 2017 at 5:23:09 PM UTC+1, Libor 'Poutnik' Stříž wrote:
> Dne 19.10.2017 v 18:19 RLH napsal(a):
> > On Thursday, October 19, 2017 at 5:11:12 PM UTC+1, Libor 'Poutnik' Striz wrote:
> >>
> >> So what ?
> >> GPS system is well aware of that.
> >> Not all in GPS is about exact atomic time.
> >
> > You don't say! And then you ignore it all to 'prove' SR/GR.
>
> You do not know what you talk about.
> BTW, What have I recently said about proofs of physical theories ?

What have I observed about theory and practice.

[Libor 'Poutnik' Stříž]

Dne 19.10.2017 v 18:29 RLH napsal(a):

As I have said, you have no idea what you are talking about.

[RLH]

On Thursday, October 19, 2017 at 5:18:44 PM UTC+1, Libor 'Poutnik' Stříž wrote:
> Dne 19.10.2017 v 17:59 RLH napsal(a):
> > On Thursday, October 19, 2017 at 3:27:58 PM UTC+1, Poutnik wrote:
> >> There is no such thing as experimental proof of physical theory.
> >> Theory predictions are confirmed or refuted.
> >
> > OK. Semantics. Does GPS confirm or refute SR.
>
> GPS confirm SR and GR.
> Rather, validity of GR allows building of working GPS,
> otherwise much more frequent empirical corrections
> would have to be made.

Empirical corrections are applied for a lot more than SR/GR as I observed.

[RLH]

On Thursday, October 19, 2017 at 5:35:11 PM UTC+1, Libor 'Poutnik' Stříž wrote:
> Dne 19.10.2017 v 18:29 RLH napsal(a):
> > I forgot
> >
> > "Because an observer on the ground sees the satellites in motion relative to them, Special Relativity predicts that we should see their clocks ticking more slowly (see the Special Relativity lecture). Special Relativity predicts that the on-board atomic clocks on the satellites should fall behind clocks on the ground by about 7 microseconds per day because of the slower ticking rate due to the time dilation effect of their relative motion [2]."
> >
> > "GR correction of clocks is 38 microseconds per day.
> > All other corrections are very minor wrt this."
> >
> > Wrong.
> >
> As I have said, you have no idea what you are talking about.

And you have never actually implemented a GPS receiver, rather obviously.

[Libor 'Poutnik' Stříž]

Dne 19.10.2017 v 18:24 RLH napsal(a):

> On Thursday, October 19, 2017 at 5:18:44 PM UTC+1, Libor 'Poutnik' Striz wrote:
>>
>> GR correction of clocks is 38 microseconds per day.
>> All other corrections are very minor wrt this.
>
> The satellite clocks are reset, usually at less than 24 hour periods.
>
> Care to ranges to the factors detailed below/above? To compare to the 38ms that is.

Care to realize value of these corrections during the resets ?
BTW 38 ms is 38 milliseconds, not microseconds.

[Libor 'Poutnik' Stříž]

Dne 19.10.2017 v 18:33 RLH napsal(a):

As you are not a scientist, it may be interesting what it is.

[Libor 'Poutnik' Stříž]

Dne 19.10.2017 v 18:35 RLH napsal(a):

> On Thursday, October 19, 2017 at 5:18:44 PM UTC+1, Libor 'Poutnik' Stříž wrote:
>>
>> GPS confirm SR and GR.
>> Rather, validity of GR allows building of working GPS,
>> otherwise much more frequent empirical corrections
>> would have to be made.
>
> Empirical corrections are applied for a lot more than SR/GR as I observed.

Then you observed a hole in a sock.

[RLH]

On Thursday, October 19, 2017 at 5:35:11 PM UTC+1, Libor 'Poutnik' Stříž wrote:
> Dne 19.10.2017 v 18:29 RLH napsal(a):
> > I forgot
> >
> > "Because an observer on the ground sees the satellites in motion relative to them, Special Relativity predicts that we should see their clocks ticking more slowly (see the Special Relativity lecture). Special Relativity predicts that the on-board atomic clocks on the satellites should fall behind clocks on the ground by about 7 microseconds per day because of the slower ticking rate due to the time dilation effect of their relative motion [2]."
> >
> > "GR correction of clocks is 38 microseconds per day.
> > All other corrections are very minor wrt this."
> >
> > Wrong.
> >
> As I have said, you have no idea what you are talking about.

Well as the actual correction is about 7ms/day you are very obviously wrong. yet again (see above).

[Paparios]

Once again you awoke this morning thinking "I have not completed my daily
task of writing nonsense" and here we are with you doing exactly that.

The official doumentation of the GPS system is freely available at:

https://www.gps.gov/technical/ particularly in the IS-GPS-200 document.

Other aspects are clearly discussed by the paper of Neil Ashby in:

https://link.springer.com/article/10.12942/lrr-2003-1

Please stop spamming this group.

[RLH]

On Thursday, October 19, 2017 at 5:37:51 PM UTC+1, Libor 'Poutnik' Stříž wrote:
> Dne 19.10.2017 v 18:24 RLH napsal(a):
> > On Thursday, October 19, 2017 at 5:18:44 PM UTC+1, Libor 'Poutnik' Striz wrote:
> >>
> >> GR correction of clocks is 38 microseconds per day.
> >> All other corrections are very minor wrt this.
> >
> > The satellite clocks are reset, usually at less than 24 hour periods.
> >
> > Care to ranges to the factors detailed below/above? To compare to the 38ms that is.
>
> Care to realize value of these corrections during the resets ?
> BTW 38 ms is 38 milliseconds, not microseconds.

Yup. Should have use 7us instead. Bite me.

[Libor 'Poutnik' Stříž]

Dne 19.10.2017 v 18:36 RLH napsal(a):

> On Thursday, October 19, 2017 at 5:35:11 PM UTC+1, Libor 'Poutnik' Stříž wrote:
>> Dne 19.10.2017 v 18:29 RLH napsal(a):
>>> I forgot
>>>

>>> "Because an observer on the ground sees the satellites in motion relative to them, Special Relativity predicts that we should see their clocks ticking more slowly (see the Special Relativity lecture). Special Relativity predicts that the on-board atomic clocks on the satellites should fall behind clocks on the ground by about 7 microseconds per day because of the slower ticking rate due to the time dilation effect of their relative motion [2].."

>>>
>>> "GR correction of clocks is 38 microseconds per day.
>>> All other corrections are very minor wrt this."
>>>
>>> Wrong.
>>>
>> As I have said, you have no idea what you are talking about.
>
> And you have never actually implemented a GPS receiver, rather obviously.

Have I pretended I did ?

It is you who pretend to understand theory of Relativity
better than physicists
and GPS system better than its designers.

With crappy knowledge of mathematics and physics.

[RLH]

On Thursday, October 19, 2017 at 5:38:54 PM UTC+1, Libor 'Poutnik' Stříž wrote:
> Dne 19.10.2017 v 18:33 RLH napsal(a):
> > On Thursday, October 19, 2017 at 5:23:09 PM UTC+1, Libor 'Poutnik' Stříž wrote:
> >> Dne 19.10.2017 v 18:19 RLH napsal(a):
> >>> On Thursday, October 19, 2017 at 5:11:12 PM UTC+1, Libor 'Poutnik' Striz wrote:
> >>>>
> >>>> So what ?
> >>>> GPS system is well aware of that.
> >>>> Not all in GPS is about exact atomic time.
> >>>
> >>> You don't say! And then you ignore it all to 'prove' SR/GR.
> >>
> >> You do not know what you talk about.
> >> BTW, What have I recently said about proofs of physical theories ?
> >
> > What have I observed about theory and practice.
>
> As you are not a scientist, it may be interesting what it is.

I am a computer scientist and an engineer. Are those not sciences?

[RLH]

On Thursday, October 19, 2017 at 5:42:57 PM UTC+1, Libor 'Poutnik' Stříž wrote:
> Dne 19.10.2017 v 18:36 RLH napsal(a):
> > On Thursday, October 19, 2017 at 5:35:11 PM UTC+1, Libor 'Poutnik' Stříž wrote:
> >> Dne 19.10.2017 v 18:29 RLH napsal(a):
> >>> I forgot
> >>>
> >>> "Because an observer on the ground sees the satellites in motion relative to them, Special Relativity predicts that we should see their clocks ticking more slowly (see the Special Relativity lecture). Special Relativity predicts that the on-board atomic clocks on the satellites should fall behind clocks on the ground by about 7 microseconds per day because of the slower ticking rate due to the time dilation effect of their relative motion [2].."
> >>>
> >>> "GR correction of clocks is 38 microseconds per day.
> >>> All other corrections are very minor wrt this."
> >>>
> >>> Wrong.
> >>>
> >> As I have said, you have no idea what you are talking about.
> >
> > And you have never actually implemented a GPS receiver, rather obviously.
>
> Have I pretended I did ?
>
> It is you who pretend to understand theory of Relativity
> better than physicists
> and GPS system better than its designers.
>
> With crappy knowledge of mathematics and physics.

Practical implementation beats theory every day.

[RLH]

Spamming? Who is guilty of spamming. I started this thread.

[Odd Bodkin]

This isn’t an engineering group. It’s a physics group. The language is that
used in physics.

If you visit Cameroon, would you expect the natives to try to translate to
English for you?

--
Odd Bodkin -- maker of fine toys, tools, tables

[Libor 'Poutnik' Stříž]

Dne 19.10.2017 v 18:40 RLH napsal(a):

> On Thursday, October 19, 2017 at 5:35:11 PM UTC+1, Libor 'Poutnik' Stříž wrote:
>> Dne 19.10.2017 v 18:29 RLH napsal(a):
>>> I forgot
>>>

>>> "Because an observer on the ground sees the satellites in motion relative to them, Special Relativity predicts that we should see their clocks ticking more slowly (see the Special Relativity lecture). Special Relativity predicts that the on-board atomic clocks on the satellites should fall behind clocks on the ground by about 7 microseconds per day because of the slower ticking rate due to the time dilation effect of their relative motion [2].."

>>>
>>> "GR correction of clocks is 38 microseconds per day.
>>> All other corrections are very minor wrt this."
>>>
>>> Wrong.
>>>
>> As I have said, you have no idea what you are talking about.
>

> Well as the actual correction is about 7ms/day you are very obviously wrong.. yet again (see above).

As I have said, you have no idea what you are talking about.

The correction is 45-7 = 38 microsecond / day

[Libor 'Poutnik' Stříž]

Dne 19.10.2017 v 18:42 RLH napsal(a):

Should have use 45-7=38 us instead.
Going to bite you soon.

[RLH]

On Thursday, October 19, 2017 at 5:45:26 PM UTC+1, Odd Bodkin wrote:
> This isn’t an engineering group. It’s a physics group. The language is that
> used in physics.
>
> If you visit Cameroon, would you expect the natives to try to translate to
> English for you?

Is this newsgroup only restricted to "SR/GR scientists"?

[Libor 'Poutnik' Stříž]

Dne 19.10.2017 v 18:43 RLH napsal(a):

> On Thursday, October 19, 2017 at 5:38:54 PM UTC+1, Libor 'Poutnik' Stříž wrote:

>>
>> As you are not a scientist, it may be interesting what it is.
>
> I am a computer scientist and an engineer. Are those not sciences?

Not, they are not in the narrower sense..
But this slide to Off topic.

[RLH]

On Thursday, October 19, 2017 at 5:47:53 PM UTC+1, Libor 'Poutnik' Stříž wrote:
> Should have use 45-7=38 us instead.
> Going to bite you soon.

The SR/GR bit is 7us.

"Because an observer on the ground sees the satellites in motion relative to them, Special Relativity predicts that we should see their clocks ticking more slowly (see the Special Relativity lecture). Special Relativity predicts that the on-board atomic clocks on the satellites should fall behind clocks on the ground by about 7 microseconds per day because of the slower ticking rate due to the time dilation effect of their relative motion [2]."

Argue with the source, not me.

[Libor 'Poutnik' Stříž]

Dne 19.10.2017 v 18:44 RLH napsal(a):

Another example of
you do not know what you talk about.

Practical implementation without a theory
is slow, expensive and inefficient naked empirism,

[Libor 'Poutnik' Stříž]

Dne 19.10.2017 v 18:50 RLH napsal(a):

> On Thursday, October 19, 2017 at 5:47:53 PM UTC+1, Libor 'Poutnik' Stříž wrote:
>> Should have use 45-7=38 us instead.
>> Going to bite you soon.
>
> The SR/GR bit is 7us.

> Argue with the source, not me.

Use then better sources, or rather read them properly.

[Odd Bodkin]

No, nor is Cameroon restricted to Cameroon natives. But if you are a
VISITOR to Cameroon, then you are expected to learn and use Cameroon ways.

[Michael Moroney]

RLH <richardli...@gmail.com> writes:

>On Thursday, October 19, 2017 at 3:27:58 PM UTC+1, Poutnik wrote:
>> There is no such thing as experimental proof of physical theory.
>> Theory predictions are confirmed or refuted.

>OK. Semantics. Does GPS confirm or refute SR.

You need GR to deal with the GPS satellites. SR isn't sufficient.

>> The first your mistake is to relate SR and GPS.

>Why? Everybody quotes it as a 'proof' all the time(pun).

Because you need GR to deal with the GPS satellites.

[Paparios]

You are the moron who does not know how to read what you post! Stop the spam!!

[Helmut Wabnig]

On Thu, 19 Oct 2017 18:18:41 +0200, Libor 'Poutnik' Striz
<pou...@privacy.net> wrote:

>Dne 19.10.2017 v 17:59 RLH napsal(a):

>> On Thursday, October 19, 2017 at 3:27:58 PM UTC+1, Poutnik wrote:
>>> There is no such thing as experimental proof of physical theory.
>>> Theory predictions are confirmed or refuted.
>>
>> OK. Semantics. Does GPS confirm or refute SR.
>

>GPS confirm SR and GR.
>Rather, validity of GR allows building of working GPS,
>otherwise much more frequent empirical corrections
>would have to be made.
>>

Wrong. After a time we would have collected
quite a lot of data which allow building predictive models.
Corrections can be based on empiric data only,
no SR or SRT or GR needed.
Same as your broker predicts your stock market loss.
He knows in advance how much you will burn in Wallstreet.

And that's sufficient. Forget relativity regarding GPS.
Well, it's an interesting tidbit, but grossly overrated.

w.

[Dono,]

On Thursday, October 19, 2017 at 9:43:25 AM UTC-7, RLH wrote:
>
> I am a computer scientist and an engineer. Are those not sciences?

You are also severely touched by dementia.

[Poutnik]

Dne 19/10/2017 v 20:19 Helmut Wabnig napsal(a):

> On Thu, 19 Oct 2017 18:18:41 +0200, Libor 'Poutnik' Striz

> Wrong. After a time we would have collected
> quite a lot of data which allow building predictive models.
> Corrections can be based on empiric data only,
> no SR or SRT or GR needed.

There is is a big difference,
if GR is needed for corrections
and if these corrections confirm what GR predicts they would be.

Once these corrections are known,
you need not GR to apply them.

Empirical data have reactive, not predictive power.
First you have to collect them, while theory can predict them.

The above is applicable to any theory versus empirical data.

[Thomas 'PointedEars' Lahn]

Libor 'Poutnik' Striz wrote:

> Dne 19.10.2017 v 17:59 RLH napsal(a):
>> On Thursday, October 19, 2017 at 3:27:58 PM UTC+1, Poutnik wrote:
>>> There is no such thing as experimental proof of physical theory.
>>> Theory predictions are confirmed or refuted.
>> OK. Semantics. Does GPS confirm or refute SR.
>
> GPS confirm SR and GR.
> Rather, validity of GR allows building of working GPS,
> otherwise much more frequent empirical corrections
> would have to be made.

Correct. Greater than zero is more frequent than zero.

> Military engineers refused to use GR corrections of satellite atomic
> clocks. Fortunately, the correction ON/OFF remote switching was
> implemented, and they gladly turned corrections ON,
> realizing the GPS does not work well without them.

Cite evidence.

>> The question is, do those terms dominate the calculations or not?
>
> This question and answer to it belongs to basic knowledge
> as prerequisite to talk about that.
> Discussion is very inferior way to gain it.

>
> GR correction of clocks is 38 microseconds per day.

The clocks are not corrected by that repeatedly, though.

> All other corrections are very minor wrt this.

Because the satellite clocks would be modified to tick at the same rate as
the ground clocks when the satellites would not be moving relative to the
ground, the corrections to the satellite clocks are only made regularly to
keep GPS time in sync with ground time because of special-relativistic
effects. So that GPS provides the correct *time signal* to the users of
*that*.

That atomic clocks would need to be corrected *afterwards* in order to
ensure proper *geopositioning* seems to me to be one of the major
misconceptions people have with GNSSs in general and GPS in particular.

The part that geopositioning has to do with SR is that the speed of light
is invariant, so you can use light travel time to determine distance, and
ultimately location. About GR I am not sure, but ISTM that if all GPS
satellite clocks would go ahead by the same amount, trilateration would
still work because the receiver has to synchronize its time with GPS time
anyway. CMIIW.


PointedEars

P.S. It is agreeable to see you posting using your real name now.
--
Heisenberg is out for a drive when he's stopped by a traffic cop.
The officer asks him "Do you know how fast you were going?"
Heisenberg replies "No, but I know where I am."
(from: WolframAlpha)

[mlwo...@wp.pl]

W dniu czwartek, 19 października 2017 20:43:55 UTC+2 użytkownik Poutnik napisał:
> Dne 19/10/2017 v 20:19 Helmut Wabnig napsal(a):
> > On Thu, 19 Oct 2017 18:18:41 +0200, Libor 'Poutnik' Striz
>
>
> > Wrong. After a time we would have collected
> > quite a lot of data which allow building predictive models.
> > Corrections can be based on empiric data only,
> > no SR or SRT or GR needed.
>
> There is is a big difference,
> if GR is needed for corrections
> and if these corrections confirm what GR predicts they would be.

Unfortunately, the predictions of your Shit
are: no correction is needed. We can leave
clocks unsychronized, as Great Guru told we
should. GPS wouldn't work if we did, of course,
but we would have a beautiful symmetry instead,
so down with the common sense! It's just a
collection of prejudices!

[Libor 'Poutnik' Stříž]

Dne 19/10/2017 v 20:44 Thomas 'PointedEars' Lahn napsal(a):

> Libor 'Poutnik' Striz wrote:
>
>>
>> GPS confirm SR and GR.
>> Rather, validity of GR allows building of working GPS,
>> otherwise much more frequent empirical corrections
>> would have to be made.
>
> Correct. Greater than zero is more frequent than zero.

I had in mind, if 38 us/d adjustment had not been done.

>
>> Military engineers refused to use GR corrections of satellite atomic
>> clocks. Fortunately, the correction ON/OFF remote switching was
>> implemented, and they gladly turned corrections ON,
>> realizing the GPS does not work well without them.
>
> Cite evidence.

The evidence circulated around the group multiple times
during the years.

I guess there will be more evidence instances,
by quick search I found this...

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5253894/

Search for Figure 2
Net fractional frequency shift of a clock in a circular orbit.
Wording is different, closer wording is probably possible to find.

>
>>> The question is, do those terms dominate the calculations or not?
>>
>> This question and answer to it belongs to basic knowledge
>> as prerequisite to talk about that.
>> Discussion is very inferior way to gain it.
>>
>> GR correction of clocks is 38 microseconds per day.
>
> The clocks are not corrected by that repeatedly, though.

Sure, as they are adjusted so on the ground in advance.
I considered it as obvious enough not to mention it.
Sorry to create feeling
I suppose this correction is done during the satellite operation.

>
>> All other corrections are very minor wrt this.
>
> Because the satellite clocks would be modified to tick at the same rate as
> the ground clocks when the satellites would not be moving relative to the
> ground, the corrections to the satellite clocks are only made regularly to
> keep GPS time in sync with ground time because of special-relativistic
> effects. So that GPS provides the correct *time signal* to the users of
> *that*.

The satellite clocks are modified to tick at the same rate as
the ground clocks when the satellites are on GPS satellite orbit,
moving by respective orbit speed.

Periodic corrections are due residual errors because of orbit
irregularities, gravity irregularities and clock errors.

> P.S. It is agreeable to see you posting using your real name now.

I am as well glad to see your manners are acceptable for me now.
You were in my killfile for a long time.

[Paul B. Andersen]

Den 19.10.2017 20.19, skrev Helmut Wabnig:
> On Thu, 19 Oct 2017 18:18:41 +0200, Libor 'Poutnik' Striz
> <pou...@privacy.net> wrote:
>
>>
>> GPS confirm SR and GR.
>> Rather, validity of GR allows building of working GPS,
>> otherwise much more frequent empirical corrections
>> would have to be made.
>>>
>
>
> Wrong. After a time we would have collected
> quite a lot of data which allow building predictive models.
> Corrections can be based on empiric data only,
> no SR or SRT or GR needed.

Sure.
They could have done what they did; launch a GPS satellite
with no GR correction, and observe it for a wile to see
how the clock was performing.
When they found that the clock ran too fast, they could
have run the satellite it into the ocean, and built a new
satellite with corrected rate, and tried again.

But fortunately, the designers of the GPS were wiser,
so they didn't have to do that:

http://www.leapsecond.com/history/Ashby-Relativity.htm
<<
At the time of launch of the first NTS-2 satellite
(June 1977), which contained the first Cesium clock
to be placed in orbit, there were some who doubted
that relativistic effects were real. A frequency
synthesizer was built into the satellite clock system
so that after launch, if in fact the rate of the clock
in its final orbit was that predicted by GR, then
the synthesizer could be turned on bringing the clock
to the coordinate rate necessary for operation.
The atomic clock was first operated for about 20 days to
measure its clock rate before turning on the synthesizer.
The frequency measured during that interval was +442.5
parts in 10^12 faster than clocks on the ground; if left
uncorrected this would have resulted in timing errors of
about 38,000 nanoseconds per day. The difference between
predicted and measured values of the frequency shift was
only 3.97 parts in 10^12, well within the accuracy capabilities
of the orbiting clock. This then gave about a 1% validation
of the combined motional and gravitational shifts for a clock
at 4.2 earth radii.
>>

It would be pretty stupid and very costly to launch a number
of satellites to measure what the correction should be, when
it can be calculated before the first satellite is launched.

https://paulba.no/paper/Ashby.pdf
https://paulba.no/paper/Initial_results_of_GPS_satellite_1977.pdf
https://paulba.no/pdf/GPS_clock_rate.pdf

--
Paul

https://paulba.no/

[mlwo...@wp.pl]

W dniu czwartek, 19 października 2017 21:39:52 UTC+2 użytkownik Paul B. Andersen napisał:
> But fortunately, the designers of the GPS were wiser,

So they piss at moronic prophecies of your insane guru
and at his "proven" impossibility to synchronize clocks
and they made clocks indicating t'=t, just like serious
clocks always did.

[Libor 'Poutnik' Stříž]

Dne 19/10/2017 v 21:19 Libor 'Poutnik' Stříž napsal(a):

> Dne 19/10/2017 v 20:44 Thomas 'PointedEars' Lahn napsal(a):
>>

>>> Military engineers refused to use GR corrections of satellite atomic
>>> clocks. Fortunately, the correction ON/OFF remote switching was
>>> implemented, and they gladly turned corrections ON,
>>> realizing the GPS does not work well without them.
>>
>> Cite evidence.
>
> The evidence circulated around the group multiple times
> during the years.
>
> I guess there will be more evidence instances,
> by quick search I found this...
>
> https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5253894/
>
> Search for Figure 2
> Net fractional frequency shift of a clock in a circular orbit.
> Wording is different, closer wording is probably possible to find.

P.S.: See also the Paul's post.

[Helmut Wabnig]

You are hopelessly backoriented and a real physics gump.

Ashby wrote his paper long after GPS (and its predecessors)
were in operation already for many years.
So much for the predictive power of theories.

w.

[Libor 'Poutnik' Stříž]

Dne 19/10/2017 v 22:09 Helmut Wabnig napsal(a):

>>
>
> You are hopelessly backoriented and a real physics gump.
>
> Ashby wrote his paper long after GPS (and its predecessors)
> were in operation already for many years.
> So much for the predictive power of theories.

So much for your understanding
what the scientific theory prediction means.

[Thomas 'PointedEars' Lahn]

Libor 'Poutnik' Stříž wrote:

> Dne 19/10/2017 v 20:44 Thomas 'PointedEars' Lahn napsal(a):
>> Libor 'Poutnik' Striz wrote:
>>> GPS confirm SR and GR.
>>> Rather, validity of GR allows building of working GPS,
>>> otherwise much more frequent empirical corrections
>>> would have to be made.
>> Correct. Greater than zero is more frequent than zero.
>
> I had in mind, if 38 us/d adjustment had not been done.

ACK.

>>> Military engineers refused to use GR corrections of satellite atomic
>>> clocks. Fortunately, the correction ON/OFF remote switching was
>>> implemented, and they gladly turned corrections ON,
>>> realizing the GPS does not work well without them.
>> Cite evidence.
>

> […]

> https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5253894/
>
> Search for Figure 2
> Net fractional frequency shift of a clock in a circular orbit.
> Wording is different, closer wording is probably possible to find.

I do not see evidence there for the colorful “ON/OFF switch” story that you
told.

> The satellite clocks are modified to tick at the same rate as
> the ground clocks when the satellites are on GPS satellite orbit,
> moving by respective orbit speed.

No, AFAIK the only modification to the clocks that has been done, simply
put, is to let the satellite clocks tick slower than normal on the ground so
that they would tick as slow in orbit as the ground clocks if they were
*not* moving relative to the ground. Because the relative motion depends on
the direction in which each satellite is going relative to the GPS ground
clocks, and cannot be known in advance. (Keep in mind that for
geopositioning to work all involved satellites must keep the same time,
*regardless* of their orbit.)

> Periodic corrections are due residual errors because of orbit
> irregularities, gravity irregularities and clock errors.

They are mainly done because the satellite orbits are _not_ geosynchronous
(you would need even more satellites and stronger senders/better receivers
then).


PointedEars
--
Q: What did the nuclear physicist post on the laboratory door
when he went camping?
A: 'Gone fission'.
(from: WolframAlpha)

[Thomas 'PointedEars' Lahn]

Paul B. Andersen wrote:

> http://www.leapsecond.com/history/Ashby-Relativity.htm
> <<
> At the time of launch of the first NTS-2 satellite
> (June 1977), which contained the first Cesium clock
> to be placed in orbit, there were some who doubted
> that relativistic effects were real. A frequency
> synthesizer was built into the satellite clock system
> so that after launch, if in fact the rate of the clock
> in its final orbit was that predicted by GR, then
> the synthesizer could be turned on bringing the clock
> to the coordinate rate necessary for operation.
> The atomic clock was first operated for about 20 days to
> measure its clock rate before turning on the synthesizer.
> The frequency measured during that interval was +442.5
> parts in 10^12 faster than clocks on the ground; if left
> uncorrected this would have resulted in timing errors of
> about 38,000 nanoseconds per day. The difference between
> predicted and measured values of the frequency shift was
> only 3.97 parts in 10^12, well within the accuracy capabilities
> of the orbiting clock. This then gave about a 1% validation
> of the combined motional and gravitational shifts for a clock
> at 4.2 earth radii.
> >>

Fascinating, thank you. This and Google allowed me to find the archived
version of the original document:

<http://www.dtic.mil/dtic/tr/fulltext/u2/a058591.pdf> (9.9M)

> It would be pretty stupid and very costly to launch a number
> of satellites to measure what the correction should be, when
> it can be calculated before the first satellite is launched.

ACK. So I understand that from then on the frequency of the satellite
clocks was already set lower accordingly before launch.

> https://paulba.no/paper/Ashby.pdf
> https://paulba.no/paper/Initial_results_of_GPS_satellite_1977.pdf
> https://paulba.no/pdf/GPS_clock_rate.pdf

I will read that later.


PointedEars
--
Q: Who's on the case when the electricity goes out?
A: Sherlock Ohms.

(from: WolframAlpha)

[Libor 'Poutnik' Stříž]

Dne 19/10/2017 v 22:25 Thomas 'PointedEars' Lahn napsal(a):

> Libor 'Poutnik' Stříž wrote:
>
>>
>> […]
>> https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5253894/
>>
>> Search for Figure 2
>> Net fractional frequency shift of a clock in a circular orbit.
>> Wording is different, closer wording is probably possible to find.
>
> I do not see evidence there for the colorful “ON/OFF switch” story that you
> told.

I was not quoting. Take it as the paraphrase of

"....... there were some who doubted

that relativistic effects were real. A frequency
synthesizer was built into the satellite clock system
so that after launch, if in fact the rate of the clock
in its final orbit was that predicted by GR, then
the synthesizer could be turned on bringing the clock

to the coordinate rate necessary for operation......"

>
>> The satellite clocks are modified to tick at the same rate as
>> the ground clocks when the satellites are on GPS satellite orbit,
>> moving by respective orbit speed.
>
> No, AFAIK the only modification to the clocks that has been done, simply
> put, is to let the satellite clocks tick slower than normal on the ground so
> that they would tick as slow in orbit as the ground clocks if they were

> *not* moving relative to the ground. [...]

In such a case, the adjustment would be 45 and not 38 us/d.

[numbernu...@gmail.com]

Specifically What are you trying to prove..in "GPS and SR. Do they really constitute a 'proof'?"


Proof of What?????

[Libor 'Poutnik' Stříž]

Dne 19/10/2017 v 22:53 Libor 'Poutnik' Stříž napsal(a):

> Dne 19/10/2017 v 22:25 Thomas 'PointedEars' Lahn napsal(a):

>>

>> No, AFAIK the only modification to the clocks that has been done, simply
>> put, is to let the satellite clocks tick slower than normal on the ground so
>> that they would tick as slow in orbit as the ground clocks if they were
>> *not* moving relative to the ground. [...]
>
> In such a case, the adjustment would be 45 and not 38 us/d.
>

P.S.: See also https://paulba.no/pdf/GPS_clock_rate.pdf

[Thomas 'PointedEars' Lahn]

Libor 'Poutnik' Stříž wrote:

> Dne 19/10/2017 v 22:53 Libor 'Poutnik' Stříž napsal(a):
>> Dne 19/10/2017 v 22:25 Thomas 'PointedEars' Lahn napsal(a):
>>> No, AFAIK the only modification to the clocks that has been done, simply
>>> put, is to let the satellite clocks tick slower than normal on the
>>> ground so that they would tick as slow in orbit as the ground clocks if
>>> they were *not* moving relative to the ground. [...]
>>
>> In such a case, the adjustment would be 45 and not 38 us/d.

*Which* adjustment? The *one-time* reduction of the clock frequency can
*only* compensate for the general-relativistic effect (gravitational time
dilation on the ground compared to orbit) of ca. +45 µs/d because that *can
be known in advance* as *it only depends on orbital height* (which is known
to be about 20'000 km).

The special-relativistic effect (time dilation due to relative motion) of
at most ca. −7 µs/d is compensated by (AFAIK) daily synchronization of GPS
satellite time with ground station time. It *has to be* because, as I
indicated before, the relative speed of a satellite to the GPS ground
station is _not_ the same for every GPS satellite, so that time dilation
is different for each satellite or, IOW, the elapsed proper times are
different.

<https://en.wikipedia.org/wiki/Global_Positioning_System#/media/File:GPS24goldenSML.gif>

> P.S.: See also https://paulba.no/pdf/GPS_clock_rate.pdf

I see nothing contradicting my statements there. In fact, I have done the
special-relativistic part of that calculation here within the last three
months more than once, using simpler notation.


PointedEars
--
Q: Why is electricity so dangerous?
A: It doesn't conduct itself.

(from: WolframAlpha)

[RLH]

On Thursday, October 19, 2017 at 5:49:44 PM UTC+1, Libor 'Poutnik' Stříž wrote:
> Dne 19.10.2017 v 18:43 RLH napsal(a):
> > On Thursday, October 19, 2017 at 5:38:54 PM UTC+1, Libor 'Poutnik' Stříž wrote:
>
> >>
> >> As you are not a scientist, it may be interesting what it is.
> >
> > I am a computer scientist and an engineer. Are those not sciences?
>
> Not, they are not in the narrower sense..
> But this slide to Off topic.

Not really. It is interesting that you do not consider others 'scientists' outside of you own discipline.

[RLH]

On Thursday, October 19, 2017 at 5:52:40 PM UTC+1, Libor 'Poutnik' Stříž wrote:
> Practical implementation without a theory
> is slow, expensive and inefficient naked empirism,

Practical implementation OF a theory, please.

[RLH]

On Thursday, October 19, 2017 at 6:12:21 PM UTC+1, Michael Moroney wrote:
> Because you need GR to deal with the GPS satellites.

See above about all the corrections that are applied. And it is 7us, not 38us, for SR/GR as Astronomers know even if you don't.

See the url supplied above.

“Mathematics is a language plus reasoning; it is like a language plus logic. Mathematics is a tool for reasoning.”
― Richard Feynman

[RLH]

On Thursday, October 19, 2017 at 5:54:40 PM UTC+1, Libor 'Poutnik' Stříž wrote:
> Dne 19.10.2017 v 18:50 RLH napsal(a):
> > On Thursday, October 19, 2017 at 5:47:53 PM UTC+1, Libor 'Poutnik' Stříž wrote:
> >> Should have use 45-7=38 us instead.
> >> Going to bite you soon.
> >
> > The SR/GR bit is 7us.
> > Argue with the source, not me.
>
> Use then better sources, or rather read them properly.

http://www.astronomy.ohio-state.edu/~pogge/Ast162/Unit5/gps.html

[RLH]

I am a visitor, true. Does that make the maths incorrect?

+ve = Positve, -ve = Negative, as anyone who has read circuit diagrams will tell you.

Read wider to stay informed in reply to Libor (I'm not going to use a separate posting to reply as Google Groups (a near RFC compliant news server), has sensible time limits to prevent spamming even on a thread I started myself)

[RLH]

Wrong, You didn't even try to refer to the source.

First link in a Google search with the quotes.

"Because an observer on the ground sees the satellites in motion relative to them, Special Relativity predicts that we should see their clocks ticking more slowly (see the Special Relativity lecture)."

"11 Mar 2017 - Real-World Relativity:"
About 296 results (0.68 seconds)

Updated: 2017 March 11
Copyright © Richard W. Pogge, All Rights Reserved.

P.S. This is my thread. How can I be spamming?

[RLH]

On Thursday, October 19, 2017 at 5:29:40 PM UTC+1, RLH wrote:
> I forgot

>
> "Because an observer on the ground sees the satellites in motion relative to them, Special Relativity predicts that we should see their clocks ticking more slowly (see the Special Relativity lecture). Special Relativity predicts that the on-board atomic clocks on the satellites should fall behind clocks on the ground by about 7 microseconds per day because of the slower ticking rate due to the time dilation effect of their relative motion [2]."
>

> "GR correction of clocks is 38 microseconds per day.

> All other corrections are very minor wrt this."
>

> Wrong.

I checked with the source (Professor Richard Pogge) and he tells me that it came form the Physics Today article listed in the url I have provided. See, I do take the time(pun) to get my fact correct, Apparently unlike those who can't be bothered.

Shame we had to disturb him.

You might also like to consider that it was his reputation you were trashing, not mine as I also observed.

Silly bunnies.

[Carl Susumu]

Einstein's special relativity (electrodynamics) and general relativity (gravity) are based on Maxwell's equations but altering the coordinate system of Maxwell's equations does not alter the fact that Maxwell's equations are derived using Faraday's induction effect that is not luminous nor is induction an ionization or particle effect. In addition, the determination that light has a constant velocity (simultaneity) likewise does not change the fact that Maxwell's theory is based on Faraday's induction effect is not luminous.

[RLH]

On Thursday, October 19, 2017 at 11:44:32 PM UTC+1, Carl Susumu wrote:
> Einstein's special relativity (electrodynamics) and general relativity...

Go away, you are cluttering up the thread.

[Carl Susumu]

RLH (simultaneity)

[RLH]

Shall I add the obvious irony that you can't even read correctly your own journals!

Visitor indeed.

[Paparios]

El jueves, 19 de octubre de 2017, 19:31:54 (UTC-3), RLH escribió:
> On Thursday, October 19, 2017 at 6:46:56 PM UTC+1, Paparios wrote:
> > El jueves, 19 de octubre de 2017, 13:50:34 (UTC-3), RLH escribió:
> > > On Thursday, October 19, 2017 at 5:47:53 PM UTC+1, Libor 'Poutnik' Stříž wrote:
> > > > Should have use 45-7=38 us instead.
> > > > Going to bite you soon.
> > >
> > > The SR/GR bit is 7us.
> > >
> > > "Because an observer on the ground sees the satellites in motion relative to them, Special Relativity predicts that we should see their clocks ticking more slowly (see the Special Relativity lecture). Special Relativity predicts that the on-board atomic clocks on the satellites should fall behind clocks on the ground by about 7 microseconds per day because of the slower ticking rate due to the time dilation effect of their relative motion [2]."
> > >
> > > Argue with the source, not me.
> >
> > You are the moron who does not know how to read what you post! Stop the spam!!
>
> Wrong, You didn't even try to refer to the source.
>

I gave you thye official references and a paper who discusses all the tiny
details but, of course, you did not even recognize the contribution.
That is a typica troll attitude.

> First link in a Google search with the quotes.
>

Again, the official sources are in the following links:

https://www.gps.gov/technical/ particularly in the IS-GPS-200 document.

Other aspects are clearly discussed by the paper of Neil Ashby in:

https://link.springer.com/article/10.12942/lrr-2003-1

Please stop spamming this group with garbage.

[Paparios]

El jueves, 19 de octubre de 2017, 19:31:54 (UTC-3), RLH escribió:
> On Thursday, October 19, 2017 at 6:46:56 PM UTC+1, Paparios wrote:

Also a very good derivation of the 38 microsecond term is given in the paper
from Paul Andersen, available in https://www.paulba.no/pdf/GPS_clock_rate.pdf

[RLH]

On Friday, October 20, 2017 at 12:07:22 AM UTC+1, Paparios wrote:
> Please stop spamming this group with garbage.

I only needed confirmation that the 7us was correct. I did kinda skip the rest I agree.

You might like to consider that this is MY thread, so the question as to who is spamming who is an interesting one.

All fighting each other on a thread I started.

Shame on you.

[RLH]

On Friday, October 20, 2017 at 12:07:22 AM UTC+1, Paparios wrote:

> I gave you thye official references and a paper who discusses all the tiny
> details but, of course, you did not even recognize the contribution.
> That is a typica troll attitude.

And your reply is more than trolling. It seeks to belittle rather than to acknowledge the accuracy of what I said. Sure it turns out that it is 45-38=7.

You might have least acknowledged that politely rather that rudely.

[Paparios]

Shame on a person who starts a thread entitled "GPS and SR. Do they really
constitute a 'proof'?" with no knowledge whatsoever about the subject.

Then, after been advised of the proper material which demonstrates that the
GPS relativistic corrections are based on GR (see the the Schwarzschild
metric on Paul's paper) you just ignore everything about it and continues to
write nonsense.

[Paparios]

There is nothing to be acknowledge there, as it is all nonsense.

The proper information is the following (which you are unable to find and read even when provided with the link to the information):

"The carrier frequencies for the L1 and L2 signals shall be coherently
derived from a common frequency source within the SV. The nominal frequency of
this source -- as it appears to an observer on the ground -- is 10.23 MHz.
The SV carrier frequency and clock rates -- as they would appear
to an observer located in the SV -- are offset to compensate for
relativistic effects. The clock rates are offset by ∆f/f =-4.4647E-10,
equivalent to a change in the P-code chipping rate of 10.23 MHz offset by a
∆f =-4.5674E-3 Hz. This is equal to 10.2299999954326 MHz."

This is the official information on the IS-GPS-200H document, section 3.3.1.1

So the GPS is NOT reset everyday NOR it is adjusted 38 microseconds per day
and NOR it is adjusted 7 microseconds per day.

Each GPS satellite atomic clock is, before launch adjusted to tick at a
frequency of 10.2299999954326 MHz and that tick rate does not change through
the life of the satellite.

Do you understand why you are providing erroneous information which I categorize
as pure SPAM.

[Carl Susumu]

Einstein special relativity (electrodynamics) and general relativity (gravity) are based on Maxwell's equations but altering the coordinate system of Maxwell's equations does not alter the fact that Maxwell's equations are derived using Faraday's induction effect that is not luminous nor is induction an ionization or particle effect. In addition, the determination that light has a constant velocity (simultaneity) likewise does not change the fact that Maxwell's theory is based on Faraday induction effect is not luminous.

[numbernu...@gmail.com]

Einstein special relativity (electrodynamics) is based on Maxwell's equations but altering the coordinate system of Maxwell's equations does not alter the fact that Maxwell's equations are derived using Faraday's induction effect that is not luminous nor is induction an ionization or particle effect. In addition, the determination that light has a constant velocity (simultaneity) or a laser range finder likewise do not change the fact that Maxwell's theory is based on Faraday induction effect is not luminous.

[Carl Susumu]

During the determination of simultaneity, what are you using to determine simultaneity. What experiment apparatus? Check.

[RLH]

On Friday, October 20, 2017 at 12:57:18 AM UTC+1, Carl Susumu wrote:
> Einstein special relativity (electrodynamics) and general relativity (gravity) are based on Maxwell's equations but altering the coordinate system of Maxwell's equations does not alter the fact that Maxwell's equations are derived using Faraday's induction effect that is not luminous nor is induction an ionization or particle effect. In addition, the determination that light has a constant velocity (simultaneity) likewise does not change the fact that Maxwell's theory is based on Faraday induction effect is not luminous.

Go away please.

[RLH]

On Friday, October 20, 2017 at 2:14:59 AM UTC+1, numbernu...@gmail.com wrote:
> Einstein special relativity (electrodynamics) is based on Maxwell's equations but altering the coordinate system of Maxwell's equations does not alter the fact that Maxwell's equations are derived using Faraday's induction effect that is not luminous nor is induction an ionization or particle effect. In addition, the determination that light has a constant velocity (simultaneity) or a laser range finder likewise do not change the fact that Maxwell's theory is based on Faraday induction effect is not luminous.

Go away please.

[mlwo...@wp.pl]

W dniu czwartek, 19 października 2017 22:25:33 UTC+2 użytkownik Thomas 'PointedEars' Lahn napisał:

> No, AFAIK the only modification to the clocks that has been done, simply
> put, is to let the satellite clocks tick slower than normal on the ground so
> that they would tick as slow in orbit as the ground clocks if they were

> *not* moving relative to the ground. Because the relative motion depends on
> the direction in which each satellite is going relative to the GPS ground
> clocks, and cannot be known in advance. (Keep in mind that for
> geopositioning to work all involved satellites must keep the same time,
> *regardless* of their orbit.)

And thus time (as defined by your idiot guru
himself) is galilean with the precision of
an acceptable error.

[mlwo...@wp.pl]

A very good, indeed, with just one "insignificant"
difference: your papers and your Shit predicts
TIME DILATION (i.e difference in clock indications)
not a CLOCK ERROR (i.e. correction).

[mlwo...@wp.pl]

W dniu piątek, 20 października 2017 01:24:07 UTC+2 użytkownik Paparios napisał:

> Then, after been advised of the proper material which demonstrates that the
> GPS relativistic corrections are based on GR (see the the Schwarzschild

A lie, as expected from fanatic trash.
Your Shit doesn't predict any correction.
It predicts time dilation.
And corrections made for GPS clocks are
directly FORBIDDEN by your idiotic
"standards".

[mlwo...@wp.pl]

W dniu piątek, 20 października 2017 01:41:43 UTC+2 użytkownik Paparios napisał:

> "The carrier frequencies for the L1 and L2 signals shall be coherently
> derived from a common frequency source within the SV. The nominal frequency of
> this source -- as it appears to an observer on the ground -- is 10.23 MHz.
> The SV carrier frequency and clock rates -- as they would appear
> to an observer located in the SV -- are offset to compensate for
> relativistic effects. The clock rates are offset by ∆f/f =-4.4647E-10,
> equivalent to a change in the P-code chipping rate of 10.23 MHz offset by a
> ∆f =-4.5674E-3 Hz. This is equal to 10.2299999954326 MHz."

"would appear". That's what a mad ideology can
do with a technical documentation.

[Ned Latham]

Poutnik wrote:
>
> There is no such thing as experimental proof of physical theory.
> Theory predictions are confirmed or refuted.

Contradicted.

[Libor 'Poutnik' Stříž]

Dne 20/10/2017 v 00:27 Thomas 'PointedEars' Lahn napsal(a):
> Libor 'Poutnik' Stříž wrote:
>
>> Dne 19/10/2017 v 22:53 Libor 'Poutnik' Stříž napsal(a):
>>> Dne 19/10/2017 v 22:25 Thomas 'PointedEars' Lahn napsal(a):

>>>> No, AFAIK the only modification to the clocks that has been done, simply
>>>> put, is to let the satellite clocks tick slower than normal on the
>>>> ground so that they would tick as slow in orbit as the ground clocks if

>>>> they were *not* moving relative to the ground. [...]
>>>
>>> In such a case, the adjustment would be 45 and not 38 us/d.
>
> *Which* adjustment? The *one-time* reduction of the clock frequency can
> *only* compensate for the general-relativistic effect (gravitational time
> dilation on the ground compared to orbit) of ca. +45 µs/d because that *can
> be known in advance* as *it only depends on orbital height* (which is known
> to be about 20'000 km).

The one time adjustment 38 and not 45 us/d
for the tweaking the clock rate.
>
> The special-relativistic effect (time dilation due to relative motion) of
> at most ca. −7 µs/d is compensated by (AFAIK) daily synchronization of GPS
> satellite time with ground station time. It *has to be* because, as I
> indicated before, the relative speed of a satellite to the GPS ground
> station is _not_ the same for every GPS satellite, so that time dilation
> is different for each satellite or, IOW, the elapsed proper times are
> different.

As I was corrected by Tom Roberts sometime ago,
-7 us/day is NOT SR correction, but GR correction,
as SR does not apply here.

It is not caused by the orbit speed itself,
not by relative speed satellite versus ground clock.

Notice there are only speed values,
nothing about relative velocities.


> <https://en.wikipedia.org/wiki/Global_Positioning_System#/media/File:GPS24goldenSML.gif>
>
>> P.S.: See also https://paulba.no/pdf/GPS_clock_rate.pdf
>
> I see nothing contradicting my statements there. In fact, I have done the
> special-relativistic part of that calculation here within the last three
> months more than once, using simpler notation.

I have done the special-relativistic part of that calculation
more than once as well, until I got corrected.

--
Poutnik ( The Pilgrim, Der Wanderer )

A wise man guards words he says,
as they say about him more,
than he says about the subject.

[Libor 'Poutnik' Stříž]

Dne 20/10/2017 v 00:31 RLH napsal(a):
> On Thursday, October 19, 2017 at 5:52:40 PM UTC+1, Libor 'Poutnik' Stříž wrote:
>> Practical implementation without a theory
>> is slow, expensive and inefficient naked empirism,
>
> Practical implementation OF a theory, please.

So nothing about beating of the theory.

[Libor 'Poutnik' Stříž]

Dne 20/10/2017 v 00:31 RLH napsal(a):

> On Thursday, October 19, 2017 at 5:54:40 PM UTC+1, Libor 'Poutnik' Stříž wrote:
>> Dne 19.10.2017 v 18:50 RLH napsal(a):

>>> On Thursday, October 19, 2017 at 5:47:53 PM UTC+1, Libor 'Poutnik' Stříž wrote:
>>>> Should have use 45-7=38 us instead.
>>>> Going to bite you soon.
>>>
>>> The SR/GR bit is 7us.

>>> Argue with the source, not me.
>>

>> Use then better sources, or rather read them properly.
>
> http://www.astronomy.ohio-state.edu/~pogge/Ast162/Unit5/gps.html
>
"The combination of these two relativistic effects means that the clocks
on-board each satellite should tick faster than identical clocks on the
ground by about 38 microseconds per day (45-7=38)! This sounds small,
but the high-precision required of the GPS system requires nanosecond
accuracy, and 38 microseconds is 38,000 nanoseconds. If these effects
were not properly taken into account, a navigational fix based on the
GPS constellation would be false after only 2 minutes, and errors in
global positions would continue to accumulate at a rate of about 10
kilometers each day! The whole system would be utterly worthless for
navigation in a very short time. "

...., or rather read them properly.

[Libor 'Poutnik' Stříž]

Dne 20/10/2017 v 01:12 RLH napsal(a):

> On Friday, October 20, 2017 at 12:07:22 AM UTC+1, Paparios wrote:
>> Please stop spamming this group with garbage.
>
> I only needed confirmation that the 7us was correct. I did kinda skip the rest I agree.

Why have you decided to ignore General Relativity
and gravitational time dilation ?

[mlwo...@wp.pl]

W dniu piątek, 20 października 2017 06:25:44 UTC+2 użytkownik Libor 'Poutnik' Stříž napisał:

> As I was corrected by Tom Roberts sometime ago,
> -7 us/day is NOT SR correction, but GR correction,

A lie, as expected from relativistic trash. It's
neither. It's a common sense correction, directly
FORBIDDEN by your insane Shit.

[Michael Moroney]

RLH <richardli...@gmail.com> writes:

>On Thursday, October 19, 2017 at 6:12:21 PM UTC+1, Michael Moroney wrote:
>> Because you need GR to deal with the GPS satellites.

>See above about all the corrections that are applied. And it is 7us, not 38
>us, for SR/GR as Astronomers know even if you don't.

>See the url supplied above.

So why did you stop reading after the explanation of the 7us part?
Did you even read the next two paragraphs of
http://www.astronomy.ohio-state.edu/~pogge/Ast162/Unit5/gps.html ?

"Further, the satellites are in orbits high above the Earth, where the
curvature of spacetime due to the Earth's mass is less than it is at the
Earth's surface. A prediction of General Relativity is that clocks closer
to a massive object will seem to tick more slowly than those located
further away (see the Black Holes lecture). As such, when viewed from the
surface of the Earth, the clocks on the satellites appear to be ticking
faster than identical clocks on the ground. A calculation using General
Relativity predicts that the clocks in each GPS satellite should get ahead
of ground-based clocks by 45 microseconds per day.

The combination of these two relativitic effects means that the clocks

[mlwo...@wp.pl]

W dniu piątek, 20 października 2017 06:52:20 UTC+2 użytkownik Michael Moroney napisał:

> The combination of these two relativitic effects means that the clocks
> on-board each satellite should tick faster than identical clocks on the
> ground by about 38 microseconds per day (45-7=38)!

Ask your fellow idiot Tom - he will tell you you're
writing nonsenses.

[Thomas 'PointedEars' Lahn]

Libor 'Poutnik' Stříž wrote:

> Dne 20/10/2017 v 00:27 Thomas 'PointedEars' Lahn napsal(a):
>> Libor 'Poutnik' Stříž wrote:
>>> Dne 19/10/2017 v 22:53 Libor 'Poutnik' Stříž napsal(a):
>>>> Dne 19/10/2017 v 22:25 Thomas 'PointedEars' Lahn napsal(a):
>>>>> No, AFAIK the only modification to the clocks that has been done,
>>>>> simply put, is to let the satellite clocks tick slower than normal on
>>>>> the ground so that they would tick as slow in orbit as the ground
>>>>> clocks if
>>>>> they were *not* moving relative to the ground. [...]
>>>> In such a case, the adjustment would be 45 and not 38 us/d.
>>
>> *Which* adjustment? The *one-time* reduction of the clock frequency can
>> *only* compensate for the general-relativistic effect (gravitational time
>> dilation on the ground compared to orbit) of ca. +45 µs/d because that
>> *can be known in advance* as *it only depends on orbital height* (which
>> is known to be about 20'000 km).
>
> The one time adjustment 38 and not 45 us/d
> for the tweaking the clock rate.

It is possible that this was done for NTS-2, but it would not be wise to do
for all GPS satellites. *Think* about it.

>> The special-relativistic effect (time dilation due to relative motion) of
>> at most ca. −7 µs/d is compensated by (AFAIK) daily synchronization of
>> GPS satellite time with ground station time. It *has to be* because, as
>> I indicated before, the relative speed of a satellite to the GPS ground
>> station is _not_ the same for every GPS satellite, so that time dilation
>> is different for each satellite or, IOW, the elapsed proper times are
>> different.
>
> As I was corrected by Tom Roberts sometime ago,
> -7 us/day is NOT SR correction, but GR correction,
> as SR does not apply here.

You have it completely backwards. Gravitational time dilation lets the
clocks on the ground tick *slower* on the ground than in orbit, so *faster*
in orbit than on the ground. *That* is where the 45 µs/d advance of the
satellite clocks *would* come from (and *did* come from in the NTS-2 test
run), and that is why the satellite clocks were made to tick *slower* than
normal from then on.

> It is not caused by the orbit speed itself,
> not by relative speed satellite versus ground clock.

Nonsense. The *maximum* 7 µs less per day come from the fact that the
maximum ground speed of a GPS satellite is

v_S ≈ 2π × (6'371 km + 20'000 km)/(12 h) ≈ 3.84 km/s

when the satellite is moving against the direction of rotation of Terra.

That gives γ = 1∕√(1 − {v_S}²∕c²) ≈ 1.00000000008203346334 and

∆T = ∆T'∕γ ≈ (86400 s)∕γ ≈ 86399.999993 s

for each day that passes on the ground, or

∆T − ∆T' ≈ −7 µs

(7 µs less) elapsed proper time per day in this orbit than on the ground
*if GR is _not_ considered*. As GR *was* considered by reducing the clock
frequency, *only* the −7 µs have to be corrected regularly so that GPS time
keeps in sync with ground time (which is important especially for one-way
clock synchronization).

> Notice there are only speed values,
> nothing about relative velocities.

You are very confused. Speed is nothing but the magnitude of velocity.

>>
<https://en.wikipedia.org/wiki/Global_Positioning_System#/media/File:GPS24goldenSML.gif>
>>
>>> P.S.: See also https://paulba.no/pdf/GPS_clock_rate.pdf
>> I see nothing contradicting my statements there. In fact, I have done
>> the special-relativistic part of that calculation here within the last
>> three months more than once, using simpler notation.
>
> I have done the special-relativistic part of that calculation
> more than once as well, until I got corrected.

Either you have misunderstood the correction, as what I just said is
*confirmed* by Paul’s calculation that *you* have cited, or you should
just not believe blindly everything that you read.

<http://www.astronomy.ohio-state.edu/~pogge/Ast162/Unit5/gps.html>


PointedEars
--
Q: What did the nuclear physicist post on the laboratory door
when he went camping?
A: 'Gone fission'.
(from: WolframAlpha)

[Libor 'Poutnik' Stříž]

Dne 20/10/2017 v 07:46 Thomas 'PointedEars' Lahn napsal(a):

This I know well.

>
>> It is not caused by the orbit speed itself,
>> not by relative speed satellite versus ground clock.

I have not said it is.

>
> Nonsense. The *maximum* 7 µs less per day come from the fact that the
> maximum ground speed of a GPS satellite is
>
> v_S ≈ 2π × (6'371 km + 20'000 km)/(12 h) ≈ 3.84 km/s

I know this speed.

>
> when the satellite is moving against the direction of rotation of Terra.
>
> That gives γ = 1∕√(1 − {v_S}²∕c²) ≈ 1.00000000008203346334 and
>
> ∆T = ∆T'∕γ ≈ (86400 s)∕γ ≈ 86399.999993 s
>
> for each day that passes on the ground, or
>
> ∆T − ∆T' ≈ −7 µs

> (7 µs less) elapsed proper time per day in this orbit than on the ground
> *if GR is _not_ considered*. As GR *was* considered by reducing the clock
> frequency, *only* the −7 µs have to be corrected regularly so that GPS time
> keeps in sync with ground time (which is important especially for one-way
> clock synchronization).

The point is, it is not SR time dilation,
but GR kinematic time dilation.

With periodic correctios in order of microseconds per days
the GPS system would be unusable.

>> Notice there are only speed values,
>> nothing about relative velocities.
>
> You are very confused. Speed is nothing but the magnitude of velocity.

Or, you are very confused about what I already know.
Speed is obviously the magnitude of velocity.

>
> Either you have misunderstood the correction, as what I just said is
> *confirmed* by Paul’s calculation that *you* have cited, or you should
> just not believe blindly everything that you read.
>
> <http://www.astronomy.ohio-state.edu/~pogge/Ast162/Unit5/gps.html>
>
>

You do not consider your mistake option, do you ?
Everywhere where I have read about the applied clock rate correction
was mentioned value 38 and not 45 us/d.

[mlwo...@wp.pl]

W dniu piątek, 20 października 2017 08:11:00 UTC+2 użytkownik Libor 'Poutnik' Stříž napisał:

> The point is, it is not SR time dilation,
> but GR kinematic time dilation.

No, poor idiot. Time dilation is when
clocks unsynchronize. When you correct
them to keep them synchronized it's
a clock error.

[Thomas 'PointedEars' Lahn]

Libor 'Poutnik' Stříž wrote:

> Dne 20/10/2017 v 00:31 RLH napsal(a):
>> On Thursday, October 19, 2017 at 5:54:40 PM UTC+1, Libor 'Poutnik' Stříž
>> wrote:
>>> Dne 19.10.2017 v 18:50 RLH napsal(a):
>>>> On Thursday, October 19, 2017 at 5:47:53 PM UTC+1, Libor 'Poutnik'
>>>> Stříž wrote:
>>>>> Should have use 45-7=38 us instead.
>>>>> Going to bite you soon.
>>>> The SR/GR bit is 7us.
>>>> Argue with the source, not me.
>>> Use then better sources, or rather read them properly.
>> http://www.astronomy.ohio-state.edu/~pogge/Ast162/Unit5/gps.html
>>
> "The combination of these two relativistic effects means that the clocks
> on-board each satellite should tick faster than identical clocks on the
> ground by about 38 microseconds per day (45-7=38)! This sounds small,
> but the high-precision required of the GPS system requires nanosecond
> accuracy, and 38 microseconds is 38,000 nanoseconds. If these effects
> were not properly taken into account, a navigational fix based on the
> GPS constellation would be false after only 2 minutes, and errors in
> global positions would continue to accumulate at a rate of about 10
> kilometers each day! The whole system would be utterly worthless for
> navigation in a very short time. "
>
> ...., or rather read them properly.

For once *he* is right and *you* are wrong; you need to *read on*.

However, I think that Pogge’s claim that geopositioning would be wrong if
the effects would not be corrected is also wrong, at least regarding the
correction of the SR effect; as that effect is so small (−7 µs *per day*,
divide that by 86'400 [seconds] to find that the difference is in the
millimeters range from one signal to the next, not kilometers) that it can
be easily solved by one-way clock synchronization with one satellite before
processing subsequent GPS signals containing satellite ID, time signal and,
if necessary, additional ephemerides data from at least four satellites.
If I am not very much mistaken, the distance between any GPS satellite and
any receiver on the planet that can see it, should be at most about
√(26'371² + 6'371²) km ≈ 27129.675 km, which light travels in 0.09 s; in
that time, the satellite clock would have fallen behind the receiver’s clock
only about 7 ps, which is irrelevant to any receiver as the precision of
their clocks is already much less.


PointedEars
--
Q: Who's on the case when the electricity goes out?
A: Sherlock Ohms.

(from: WolframAlpha)

[Thomas 'PointedEars' Lahn]

Libor 'Poutnik' Stříž wrote:

> Dne 20/10/2017 v 01:12 RLH napsal(a):
>> On Friday, October 20, 2017 at 12:07:22 AM UTC+1, Paparios wrote:
>>> Please stop spamming this group with garbage.
>> I only needed confirmation that the 7us was correct. I did kinda skip the
>> rest I agree.
>
> Why have you decided to ignore General Relativity
> and gravitational time dilation ?

Because the engineers of GPS knew general relativity, and after confirming
that with NTS-2, they set all satellite clocks to tick slower than normal
on the ground, so that they would tick in orbit as fast/slow as the ground
clocks when not considering *SR* time dilation.


PointedEars
--
I heard that entropy isn't what it used to be.

(from: WolframAlpha)

[Libor 'Poutnik' Stříž]

Dne 20/10/2017 v 08:33 Thomas 'PointedEars' Lahn napsal(a):

> Libor 'Poutnik' Stříž wrote:
>

> For once *he* is right and *you* are wrong; you need to *read on*.
>
> However, I think that Pogge’s claim that geopositioning would be wrong if
> the effects would not be corrected is also wrong, at least regarding the
> correction of the SR effect; as that effect is so small (−7 µs *per day*,
> divide that by 86'400 [seconds] to find that the difference is in the
> millimeters range from one signal to the next, not kilometers) that it can
> be easily solved by one-way clock synchronization with one satellite before
> processing subsequent GPS signals containing satellite ID, time signal and,
> if necessary, additional ephemerides data from at least four satellites.
> If I am not very much mistaken, the distance between any GPS satellite and
> any receiver on the planet that can see it, should be at most about
> √(26'371² + 6'371²) km ≈ 27129.675 km, which light travels in 0.09 s; in
> that time, the satellite clock would have fallen behind the receiver’s clock
> only about 7 ps, which is irrelevant to any receiver as the precision of
> their clocks is already much less.
>
>

I am aware about the trilateration and satellite position aspects.

But as modern GPS methods with the terrestrial aid
have sub centimeter accuracy....


BTW see https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5253894/

Equation 36 legend:

" The negative sign in this result means that the standard clock in
orbit is beating too fast, primarily because its frequency is
gravitationally blueshifted. In order for the satellite clock to appear
to an observer on the geoid to beat at the chosen frequency of 10.23
MHz, the satellite clocks are adjusted lower in frequency so that the
proper frequency is: ( formula ) This adjustment is accomplished on
the ground before the clock is placed in orbit."

The correction factor is 4.4647e-10
If multiplied by sideric day 86164 s...

..you get 38.47 us/day

Not 45...

[Thomas 'PointedEars' Lahn]

Libor 'Poutnik' Stříž wrote:

> Dne 20/10/2017 v 07:46 Thomas 'PointedEars' Lahn napsal(a):
>> Libor 'Poutnik' Stříž wrote:
>>> Dne 20/10/2017 v 00:27 Thomas 'PointedEars' Lahn napsal(a):
>>>> Libor 'Poutnik' Stříž wrote:
>>>>> Dne 19/10/2017 v 22:53 Libor 'Poutnik' Stříž napsal(a):
>>>>>> Dne 19/10/2017 v 22:25 Thomas 'PointedEars' Lahn napsal(a):

>>>> The special-relativistic effect (time dilation due to relative motion)
>>>> of at most ca. −7 µs/d is compensated by (AFAIK) daily synchronization
>>>> of
>>>> GPS satellite time with ground station time. It *has to be* because,
>>>> as I indicated before, the relative speed of a satellite to the GPS
>>>> ground station is _not_ the same for every GPS satellite, so that time
>>>> dilation is different for each satellite or, IOW, the elapsed proper
>>>> times are different.
>>>
>>> As I was corrected by Tom Roberts sometime ago,
>>> -7 us/day is NOT SR correction, but GR correction,
>>> as SR does not apply here.
>>
>> You have it completely backwards. Gravitational time dilation lets the
>> clocks on the ground tick *slower* on the ground than in orbit, so
>> *faster* in orbit than on the ground.
>> *That* is where the 45 µs/d advance of the
>> satellite clocks *would* come from (and *did* come from in the NTS-2 test
>> run), and that is why the satellite clocks were made to tick *slower*
>> than normal from then on.
>
> This I know well.

Then I do not understand why it is not obvious to you that the gravitational
time dilation, the general-relativistic effect, already *has been corrected*
by letting the satellite clocks tick slower. What is left to correct
regularly for timekeeping is only the time dilation due to relative motion,
the −7 µs/d.

>>> It is not caused by the orbit speed itself,
>>> not by relative speed satellite versus ground clock.
>
> I have not said it is.

Are you kidding me? You are quoting your own statement there.

> The point is, it is not SR time dilation,

Yes, it is.

> but GR kinematic time dilation.

How did you get the idea that there would be such a thing? Gravitational
time dilation is a general-relativitistic effect because of differences in
spacetime curvature. Time passes slower at greater spacetime curvature than
at less; slower closer to the center of mass than far away from it; slower
near the surface of a planet than in its orbit. No motion whatsoever has
anything to do with that. (Time dilation due to relative motion is a
*special*-relativistic effect.)

General relativity is mainly a theory of gravitation that describes
gravitation only as an apparent force, the observable effect of the
curvature of spacetime in a region of spacetime, that corresponds to
the density of stress, energy, and momentum there.

> With periodic correctios in order of microseconds per days

Rather _tens_ of microseconds per _day_.

> the GPS system would be unusable.

It would be unusuable as a *time* reference, but I doubt it would be
unusuable for geopositioning, as I just laid out in the other thread.

>>> Notice there are only speed values,
>>> nothing about relative velocities.
>> You are very confused. Speed is nothing but the magnitude of velocity.
>
> Or, you are very confused about what I already know.
> Speed is obviously the magnitude of velocity.

Then why are you talking about a difference between “speed values” and
“relative velocities”?

>> Either you have misunderstood the correction, as what I just said is
>> *confirmed* by Paul’s calculation that *you* have cited, or you should
>> just not believe blindly everything that you read.
>>
>> <http://www.astronomy.ohio-state.edu/~pogge/Ast162/Unit5/gps.html>
>
> You do not consider your mistake option, do you ?

I do. Therefore I have done the calculation *again*, compared my result
with Paul’s result that *you* cited, and Pogge’s description that *you*
cited (to RLH) and I cited, and found that our results approximately match.
From this I have to conclude that I must have done at least something right
there.

If you do not think that Paul’s calculation and results are correct, if you
are now saying the opposite that he says, then why have you cited it to make
a point? Likewise, why are you citing Pogge when your claims contradict his
explanation?

> Everywhere where I have read about the applied clock rate correction
> was mentioned value 38 and not 45 us/d.

You have not read properly what you have cited. In particular, as I just
pointed out in the other thread, you have not read Pogge’s explanation,
that you had cited too, *to the end*.


HTH

PointedEars
--
Q: What happens when electrons lose their energy?
A: They get Bohr'ed.

(from: WolframAlpha)

[Libor 'Poutnik' Stříž]

Dne 20/10/2017 v 09:10 Thomas 'PointedEars' Lahn napsal(a):

> Libor 'Poutnik' Stříž wrote:
>

>>
>> This I know well.
>
> Then I do not understand why it is not obvious to you that the gravitational
> time dilation, the general-relativistic effect, already *has been corrected*
> by letting the satellite clocks tick slower. What is left to correct
> regularly for timekeeping is only the time dilation due to relative motion,
> the −7 µs/d.

By quick check you can realize the applied relative clock rate offset
4.4647e-10 relates to 38 us/d and not 45 us/d,
what would be purely gravitational GR effect.

In my understanding, GR calculation based on SS metric
involves both potential an kinetic energy of the clocks.
That is why speeds and not relative velocities.

>
>>>> It is not caused by the orbit speed itself,
>>>> not by relative speed satellite versus ground clock.
>>
>> I have not said it is.
>
> Are you kidding me? You are quoting your own statement there.

This was error. I had to be responding to or thinking about something
else. I stand with it ( with corrected typo )
"It is caused by the orbit speed itself,

not by relative speed satellite versus ground clock."

>> but GR kinematic time dilation.
>
> How did you get the idea that there would be such a thing? Gravitational
> time dilation is a general-relativitistic effect because of differences in
> spacetime curvature. Time passes slower at greater spacetime curvature than
> at less; slower closer to the center of mass than far away from it; slower
> near the surface of a planet than in its orbit. No motion whatsoever has
> anything to do with that. (Time dilation due to relative motion is a
> *special*-relativistic effect.)

Unless it is due kinetic energy. In such a case,
the kinematic part is constant and applied to the clock, as is done.

4.4647e-10 relates to 38 us/d and not 45 us/d,
what would be purely gravitational GR effect.

[Thomas 'PointedEars' Lahn]

Libor 'Poutnik' Stříž wrote:

> Dne 20/10/2017 v 08:33 Thomas 'PointedEars' Lahn napsal(a):

>> However, I think that Pogge’s claim that geopositioning would be wrong if
>> the effects would not be corrected is also wrong, at least regarding the
>> correction of the SR effect; as that effect is so small (−7 µs *per day*,
>> divide that by 86'400 [seconds] to find that the difference is in the
>> millimeters range from one signal to the next, not kilometers) that it
>> can be easily solved by one-way clock synchronization with one satellite

>> before processing subsequent GPS signals […]

>
> I am aware about the trilateration and satellite position aspects.
>
> But as modern GPS methods with the terrestrial aid
> have sub centimeter accuracy....

Cite evidence.

> BTW see https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5253894/

The publication on the Web site of the US National Library of *Medicine*
does not fill me with confidence, but the credentials of the author do.

> Equation 36 legend:
>
> " The negative sign in this result means that the standard clock in
> orbit is beating too fast, primarily because its frequency is
> gravitationally blueshifted. In order for the satellite clock to appear
> to an observer on the geoid to beat at the chosen frequency of 10.23
> MHz, the satellite clocks are adjusted lower in frequency so that the
> proper frequency is: ( formula ) This adjustment is accomplished on
> the ground before the clock is placed in orbit."
>
> The correction factor is 4.4647e-10

Apparently.

> If multiplied by sideric day 86164 s...

Why you think the sideric day would be relevant here?

> ..you get 38.47 us/day
>
> Not 45...

One gets approximately the same value using the civil day (86400 s).

AISB, it is possible that the normal clock correction already includes the
SR *worst case*. Maybe this is then done because the majority of satellites
would travel against the rotation direction of Terra, and the correction
would reduce the frequency of clock synchronization to compensate SR time
dilation. Who knows. (Ashby does not seem to explain why; indeed, he
provides no explicit references to substantiate his claims in that regard.)

That does not change the fact that there *is* SR time dilation, contrary to
what you claimed.

And if you agree with Ashby:

Why have you cited Paul B. Andersen to me who contradicts Ashby there?
Why have you cited and quoted Pogge incompletely to RLH who contradicts
Ashby there?
Why are you talking about fantasies like “GR kinetic time dilation”?


PointedEars
--
Q: What did the nuclear physicist order for lunch?
A: Fission chips.

(from: WolframAlpha)