Re: Evidences for the ether

Sorcerer wrote:
"Paul B. Andersen" <paul.b.andersen@xxxxxxxxxxxxxxxx> wrote in message news:ebqkqg$2mo$1@xxxxxxxxxxxxxxxxxxx
| Sorcerer wrote:
| > "Paul B. Andersen" <paul.b.andersen@xxxxxxxxxxxxxxxx> wrote in message
| > news:ebpiph$1j8$1@xxxxxxxxxxxxxxxxxxx
| > | Sorcerer wrote:
| > | > "Paul B. Andersen" <paul.b.andersen@xxxxxxxxxxxxxxxx> wrote in message
| > | > news:ebo54g$s3s$1@xxxxxxxxxxxxxxxxxxx
| > | > | Sorcerer wrote:
| > | > | >
| > | > | > To find exact position on Earth you need to know the exact position
| > of
| > | > the
| > | > | > satellite, not just it's time.
| > | > | > Satellites are perturbed in their orbit (mostly by the moon, which
| > also
| > | > | > perturbs sea level) but their position is regularly updated from
| > ground
| > | > | > stations so that they can tell you where they are.
| > | > | > No engineer is going to sit at a desk in front of a monitor and ask
| > | > | > where each satellite is or what its time is, the upload is fully
| > | > | > automated.
| > | > | > Their time is also uploaded, they do not correct themselves. The
| > system
| > | > | > works, even though their clocks are damaged, and would still work if
| > | > they
| > | > | > were not damaged.
| > | > |
| > | > | > The correction of the damage, 38 usec per day,
| > | > | > corresponds to 0.4909981824 inches per day, far less than the
| > stated
| > | > | > accuracy of the system. Uncorrected, you'll be 15 feet out of
| > position
| > | > | > in a year.
| > | > |
| > | > | Hilarious, how stupid the engineers who designed the GPS were, isn't
| > it?
| > | > :-)
| > | > | They didn't understand that the clocks could run wrong by
| > | > | 3 ms a day, and the precision of the GPS would still be better than 1
| > m!
| > | > | So why did they put expensive atomic clocks in the satellites when
| > | > | oven controlled crystal clocks could do the job?
| > | >
| > | > To make more money, it was a government contract.
| > | >
| > | > | Probably because they didn't consult the electrical engineer
| > Androcles!
| > | >
| > | > My fees were too low to make a fat profit on. Those guys were not as
| > | > stupid as you imagine, in the USA the dollar is king. Why should they
| > | > consult me anyway?
| > |
| > | Because you know what they - and the rest of the world - don't.
| > | Namely how the GPS works.
| > | I think you should enlighten us, Androcles.
| > | How does a GPS receiver determine it's position?
| >
| > Look up old posts, I'm not repeating myself for a troll and proven liar.
| > It does me no good to even quote references, you'll claim that I fabricated
| > them.
| > You've been enlightened.
| >
| > Androcles.
|
| There are no old posts to look up, because you never explained
| how the GPS works.
|
| You know so much, Androcles, so I would appreciate it very
| much if you explained it to a stupid ignorant troll like me.
| So please help me.

Your snivelling and whining fool nobody.

|
| Let us take one step at the time.
| A GPS satellite emits its time together with data that make
| it possible to know its position when the signal was sent.
| A receiver receives this signal.
| How can the receiver find its distance from the satellite?

Signals are recieved from a minimum of three satellites which
inform the receiver of their position and the time sent.
An algorithm in the receiver then computes position based
on that data. The exact details of the algorithm are not crucial
to the discussion since it depends on the manufacturer of the
reciever.

Let's stop here for a bit.
"An algorithm in the receiver then computes position based
on that data." is no explanation.
I don't need the exact algorithm, the principle will do.

So the receiver knows the position of the satellites
and the time of the satellite clocks when the signals were sent.
So how does the receiver from these data calculate the distance
to each satellite? I am only asking for the basic principle.


The following is no serious attempt to explain how
the GPS works, and was never meant as such.

One would expect to get good altitude information from
a satellite directly overhead, but it turns out this is not the case
for a large number of receivers due to the uncertainty of
a GPS clock which was damaged (Ghost's term) prior to
launch to agree with some idiotic reliance on the foolish idea
that the speed of the signal was to be from A to A in time t'A-tA,
whereas in fact the time of the signal is from A to B in time tB-tA, A
being the satellite and B being the receiver. The direct distance to the
satellite is therefore AB/(tB-tA), tA been sent as part of the data,
the signal is not returned to the satellite with tB being
half (t'A-tB) + tA
because the satellite is MOVING and it does not want to know
where it is because it cannot do anything about it anyway.

This foolishness may be found in
http://www.fourmilab.ch/etexts/einstein/specrel/www/figures/img7.gif

However, GPS is most useful for sailors where altitude is not
a consideration, and aircraft still rely on barometric and radar
altitude. GPS can be used to navigate on land, but this is more
of a gimmick than a necessity unless you happen to be a soldier
in a wilderness. Cell phones could do a better job in those regions
where gimmicks are considered status symbols, and so my
son-in-law (#2) has GPS and a mobile phone, as does my
niece's boyfriend. I too have a mobile phone, but for the simple
reason that it is cheaper than renting a land line and not because it
plays ringtones. I seldom use it.
I navigate by the sun, stars and (predominantly) road signs,
I am always instinctively aware of the direction of North.
Altitude I find rather difficult with instrumentation, but I cannot
rely upon GPS for accuracy.

Could we get back to the issue, please?

| You wouldn't repeat yourself, Androcles, because you never
| explained this.
| But you do know the answer, don't you?

Yes. The details of some of the algorithms I would perhaps need
to check on, I do not recall them in detail, but I'm not going to
because they do not particularly interest me. Were I being paid
as a consultant, I would do so. Are you planning on paying me as
a consultant?
I thought not.

You claim to know how the GPS works, so please explain.
I am not asking for the details of any algorithm, I am
only asking for the basic principle.

You couldn't have written the following about how the clock precision
affects the precision of the positioning if you didn't know the principle
of how that position is determined, could you?
Androcles wrote:
|The correction of the damage, 38 usec per day,
|corresponds to 0.4909981824 inches per day, far less than the stated
|accuracy of the system. Uncorrected, you'll be 15 feet out of position
|in a year.

Or could you?

You can, however, award me an honorary degree from Agder
for services rendered above and beyond the call of duty, to go
alongside my diploma which you were gracious enough to award.
I have it framed, although it is gathering dust somewhere... probably
under my bed. Oh, well...
Androcles.

I will award you another diploma when you have
explained how the GPS works.
But you will have to deserve it.
You have explained nothing so far.

Paul
.

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