Re: List of Cranks here

From: Tom Potter (tdp_at_earthlink.net)
Date: 03/19/05 

Date: Sat, 19 Mar 2005 21:49:47 +0800

"Sam Wormley" <swormley1@mchsi.com> wrote in message
news:bsC_d.148637$tl3.147050@attbi_s02...
> Tom Potter wrote:
>
>> 9. There is some variation in the time it takes the
>> signal to reach the receiver due to multi paths
>> taken by the radio wave to the GPS receiver,
>> so GPS receivers are programmed to compute out the
>> multi-path variations, and to compute the time,
>> using the most reliable data it gets from
>> several satellites.
>
> Right-hand circular polarization helps, but GPS receivers that
> do an excellent job of multipath mitigation are expensive.
>
>> 10. The GPS satellites broadcast on two carrier frequencies:
>> L1 at 1575.42 MHz and L2 at 1227.6 MHz.
>> They transmit a "coarse acquisition code" at 1.0 bits per nanosecond and
>> a "precision code" at a bit rate of 10.230 bits per nanosecond.
>
> C/A bit rate is 50 bps
>
> CrackPotter should read and *learn* from
> http://www.navcen.uscg.gov/pubs/gps/sigspec/default.htm
>
>> By averaging data from multiple satellites,
>> a receiver can reduce the timing uncertainty
>> due to multipaths, and can reduce the error sphere
>> by only averaging where the error spheres
>> of several satellites overlap.
>
> Not the way it works, Potter. If you want to learn something about GPS,
> start
> with the Interface Control Document (ICD)
> http://www.navcen.uscg.gov/pubs/gps/icd200/default.htm
>
>> In order to measure the time interval most accurately,
>> a quasi-random code is used. The GPS receiver performs
>> a auto-correlation on the quasi-random signal
>> in order to eliminate the jitter in the leading edge
>> of the transmitted signal, caused by transmitter noise,
>> receiver noise, environmental noise, multipath signal combining,
>> jamming, etc.
>
> GPS uses direct sequence spread spectrum. CrackPotter should read
> an *learn* from
> http://www.navcen.uscg.gov/pubs/gps/sigspec/default.htm
>
>> In other words, a segment of the quasi-random signal is
>> incrementally delayed, and multiplied by the signal stream.
>> If two string of random numbers are multiplied,
>> a maximum occur when and if the strings match,
>> otherwise the product tends toward zero.
>
> Correlation receiver
> http://www.navcen.uscg.gov/pubs/gps/gpsuser/gpsuser.pdf
>>
>> The Military can play games with the GPS signals by
>> juggling the "precision code" signals,
>> and thus messing up the accuracy
>> to which a GPS receiver can the time interval.
>
> P code is encrypted creating P(Y) code. The term "juggling" is
> misleading--CrackPotter may have used it as he may not understand
> encryption.
>
>> In summary, the largest contributor
>> to time transfer uncertainty is caused by
>> variations path delay, due to signals reflected
>> off mountains, buildings, etc., and as note,
>> much of the path delay errors can be averaged out,
>> because the satellites are moving, and signals
>> are received from several satellites.
>
> GPS error sources
> http://edu-observatory.org/gps/gps_accuracy.html
>
>> The best GPS receivers can,
>> by using the methods addressed above,
>> reduce the uncertainty in time to about one nanosecond,
>> which amounts to a sphere of uncertainty of about one foot.
>
> Survey instruments routinely achieve a few millimeter relative
> position accuracy making use of GPS signals from space and a fixed
> reference receiver.
> http://edu-observatory.org/gps/dgps.html
>
>> The errors due to GR effects,
>> aren't even a factor in the GPS system.
>
> There are a dozen relativistic corrections incorporated in GPS
> http://www.edu-observatory.org/gps/gps_books.html#Relativity
>
>> It is interesting to see that an oft quoted
>> ( By the GR pushers ) Neil Ashby states:
>> "It is not easy right now to perform relativity tests using GPS
>> because satellite clocks are actively corrected
>> to within 1 microsecond of Universal Coordinated Time."
>
> CrackPotter quotes out of context from:
> http://www.phys.lsu.edu/mog/mog9/node9.html
>
>> As can be seen, the corrections that are sent to
>> the GPS clocks to
>> "actively correct to within 1 microsecond of Universal Coordinated Time."
>
> GPS is, in fact, correct to a few nanoseconds
> http://tycho.usno.navy.mil/gpstt.html
>
>
>> are a clear indication of how the clocks on the ground,
>> and the clocks on the satellites differ,
>> and that an examination of these corrections would
>> clearly show what differential effects were operative.
>>
>> The bottom line is,
>
> ... that CrackPotter doesn't the relativistic effects and correction
> implemented in the Global Positioning System

I am pleased to see that Sam Wormley posted
references that confirm the correctness of my posts,
even though he implies that these references do not.

Perhaps Sam doesn't read, or comprehend
the data put out by his references.

Rather than post references
and make unsubstantiated inferences,
I am looking forward to seeing Sam
join the issue, and discuss the specifics
of his inferences.

It is interesting to see Sam assert:
"There are a dozen relativistic corrections incorporated in GPS."

Using twelve or more hacks of a single model,
smacks more of numerology than of rational thinking.

I dare say that a creative hacker could use twelve hacks
to model most any single fixed situation,
and related it to some model.
I have seen numerous such hacks that yield
the fine structure constant, the mass of the electron, etc.

Secondly, GR not a viable, cost-effective approach
to designing any real world system.
It generates more heat than light,
and wastes time, money and minds
on the pursuit of such fantasies as
worm holes, black holes, time travel, etc.

Its' primary use is by members of the GR industry
to bamboozle politicians out of the taxpayers money,
and by charlatans to try to con folks into thinking
that hey are privy to powerful, esoteric knowledge.

GR is a Tower of Babel,
that wastes an enormous amount of time, money and minds.

Hopefully, Sam will post DETAILS on SPECIFIC circuits,
and programs in the ground stations, birds, and
GPS receivers that use a GTR model.

A wasted mind is a terrible thing!

Disclaimer:
Although Sam's post is basically a flame,
I responded to it in sci.physics,
rather than alt.flame,
as he did raise a couple of points
that needed to be addressed in sci.physics. 

-- 
Tom Potter
http://home.earthlink.net/~tdp
http://photos.yahoo.com/tdp1001

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