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Groups > sci.physics.relativity > #422220
| From | Serg io <invalid@invalid.com> |
|---|---|
| Newsgroups | sci.physics.relativity, sci.physics |
| Subject | Re: GPS Again. |
| Date | 2017-06-10 23:20 -0500 |
| Organization | Aioe.org NNTP Server |
| Message-ID | <ohigf0$ir7$1@gioia.aioe.org> (permalink) |
| References | (7 earlier) <eq0vtmFo6dqU1@mid.individual.net> <ohgidq$1pjn$1@gioia.aioe.org> <eq3jm6Fbp3jU1@mid.individual.net> <ohi9e4$ai1$1@gioia.aioe.org> <9-WdndqChJsuJqHEnZ2dnUU7_83NnZ2d@giganews.com> |
Cross-posted to 2 groups.
On 6/10/2017 10:40 PM, Tom Roberts wrote:
> On 6/10/17 6/10/17 9:20 PM, Serg io wrote:
>> there are relativistic effects that must be backed out, Clocks in
>> orbit appear to run faster (38.3 μsec/day = 11.5 km/day!)
>> ⇒tuned at 10.22999999543 MHz before launching (g.)
>
> Yes, a receiver on earth receives satellite signals with a clock
> frequency of 10.23000000000 MHz, because they were generated at
> 10.22999999543 MHz and relativistic effects bring it to that value, as
> required to keep GPS time in sync with UTC (which is defined on the geoid).
>
> The relativistic effects must NOT be "backed out", as they are essential
> to the operation of the GPS.
it is a identifiable and calculable error term which is removed
>
>> −Clocks speed is a function of orbit eccentricity (45 nsec= 14 m)
>
> Satellite clock tick rate is indeed a function of the satellite's
> orbital eccentricity; its contribution to the error budget is quite small.
>
> Your number is just the vacuum speed of light, unrelated to
> orbital eccentricities.
nope, 14 meter higher is 45 ns longer...
>
>> 1 Measure arrival time of GPS signals from several satellites
>> simultaneously
>
> This can only be done approximately -- their signals do NOT arrive
> simultaneously.
the statement says 'measure' simultaneously, not arrive .....
> The receiver relies on its local clock to determine the
> time differences between the arrivals of the various time markers.
part of it, but the signals are corrolated...
> The
> error introduced by the inaccuracy of the local clock is only
> significant for the overall time offset of the local clock (the local
> clock tick rate is good enough that its error is negligible over these
> short durations).
in some cases
>
>> 2 Decode the GPS signal and figure out the signal propagation time
>> (tr-te), multiply by c= “pseudoranges” (= GPS data, or observables)
>
> Yes. Contrary to claims in this thread, this is where the vacuum speed
> of light enters the calculation.
>
>> 3 Decode the navigation message and convert it into satellite positions
>>
>> 4 Use at least 4 pseudoranges acquired at the same time from 4
>> different satellites to compute a position in an ECEF frame.
>
> No. The pseudoranges determine position in the ECI frame. The
> navigational messages also contain the details of the transform from ECI
> to ECEF.
see #3 above
>
> The key property of the GPS is that each satellite clock always displays
> the GPS time that an ECI coordinate clock at its current location would
> display. Since the vacuum speed of light is isotropically c in the ECI
> coordinates, the calculation of pseudo ranges is straightforward
> (corrections for the effects of propagation in air are generally small).
small errors cause poor resolution,
>
>> 5 Convert ECEF position into latitude-longitude-height in any geodetic
>> system (for instance WGS84).
>>
>> (note the sattilite positions must be known, the ECEF is the
>> intersection of 3 spheres
>
> The ECI position is the intersection of FOUR spheres, or it is the best
> fit among five or more spheres (limited to 12 because that is the
> largest number of GPS satellites visible from any point on earth at any
> given time).
>
> Most receivers require at least four satellites, because
> they must determine 4 values of the position in the ECI:
> {x,y,z,t}. Some specialized receivers have algorithms capable
> of determining position with fewer satellites by using
> additional information (e.g. watching the satellites for a
> long time, or knowing the altitude, time, or previous position
> independently).
>
> Tom Roberts
>
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GPS Again. "HGW, DSc." <HG@....> - 2017-05-27 06:49 +1000
Re: GPS Again. Ckeho Baùkora <unukn@owyqar.og> - 2017-05-26 21:01 +0000
Re: GPS Again. "David (Lord Kronos Prime) Fuller" <fuller.david@hotmail.com> - 2017-05-26 15:49 -0700
Re: GPS Again. Ckeho Baùkora <unukn@owyqar.og> - 2017-05-27 09:20 +0000
Re: GPS Again. dancouriann@gmail.com - 2017-05-26 15:50 -0700
Re: GPS Again. Odd Bodkin <bodkinodd@gmail.com> - 2017-05-26 17:58 -0500
GPS Again. "David (Lord Kronos Prime) Fuller" <fuller.david@hotmail.com> - 2017-05-26 16:14 -0700
GPS Again. "David (Lord Kronos Prime) Fuller" <fuller.david@hotmail.com> - 2017-05-26 16:38 -0700
Re: GPS Again. xxein1x1@gmail.com - 2017-05-26 16:25 -0700
Re: GPS Again. moroney@world.std.spaamtrap.com (Michael Moroney) - 2017-05-27 00:18 +0000
Re: GPS Again. Tom Roberts <tjroberts137@sbcglobal.net> - 2017-05-26 19:51 -0500
Re: GPS Again. Ckeho Baùkora <unukn@owyqar.og> - 2017-05-27 10:37 +0000
Re: GPS Again. Tom Roberts <tjroberts137@sbcglobal.net> - 2017-05-30 09:57 -0500
Re: GPS Again. Helmut Wabnig <hwabnig@.- --- -.dotat> - 2017-05-30 20:52 +0200
Re: GPS Again. Ernest Rivers <erwm@weicnne.ac> - 2017-05-30 19:17 +0000
Re: GPS Again. Tom Roberts <tjroberts137@sbcglobal.net> - 2017-05-30 15:23 -0500
Re: GPS Again. Helmut Wabnig <hwabnig@.- --- -.dotat> - 2017-05-30 22:53 +0200
Re: GPS Again. Ernest Schwanenflügel <erwm@wanenf.oa> - 2017-05-30 20:59 +0000
Re: GPS Again. Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2017-05-31 00:42 +0200
Re: GPS Again. Tom Roberts <tjroberts137@sbcglobal.net> - 2017-05-30 19:03 -0500
Re: GPS Again. Serg io <invalid@invalid.com> - 2017-05-30 21:30 -0500
Re: GPS Again. Serg io <invalid@invalid.com> - 2017-05-30 19:01 -0500
Re: GPS Again. Ernest Rivers <erwm@weicnne.ac> - 2017-05-30 19:15 +0000
Re: GPS Again. Sylvia Else <sylvia@not.at.this.address> - 2017-06-09 11:37 +1000
Re: GPS Again. Jim Limey <eeug@dnne.ri> - 2017-06-09 14:32 +0000
Re: GPS Again. Serg io <invalid@invalid.com> - 2017-06-09 12:51 -0500
Re: GPS Again. Kitubu Nkyaku <akntuu@buwkau.kk> - 2017-06-09 18:52 +0000
Re: GPS Again. "HGW..." <hgw@....> - 2017-06-10 09:23 +1000
Re: GPS Again. Sylvia Else <sylvia@not.at.this.address> - 2017-06-10 11:23 +1000
Re: GPS Again. Sylvia Else <sylvia@not.at.this.address> - 2017-06-10 11:21 +1000
Re: GPS Again. Kitubu Nkyaku <akntuu@buwkau.kk> - 2017-06-10 10:42 +0000
Re: GPS Again. Serg io <invalid@invalid.com> - 2017-06-10 19:38 -0500
Re: GPS Again. Nými Icelulózy <ejienm@wzsfwe.ul> - 2017-06-16 11:30 +0000
Re: GPS Again. Sегgi о <iinvalid@invalid.com> - 2017-06-16 10:40 -0500
Re: GPS Again. Sylvia Else <sylvia@not.at.this.address> - 2017-06-11 11:11 +1000
Re: GPS Again. Serg io <invalid@invalid.com> - 2017-06-10 21:20 -0500
Re: GPS Again. Sylvia Else <sylvia@not.at.this.address> - 2017-06-11 12:31 +1000
Re: GPS Again. Tom Roberts <tjroberts137@sbcglobal.net> - 2017-06-10 22:40 -0500
Re: GPS Again. Serg io <invalid@invalid.com> - 2017-06-10 23:20 -0500
Re: GPS Again. "HGW, DSc." <HG@....> - 2017-06-11 05:14 +1000
Re: GPS Again. "Paul B. Andersen" <relativity@paulba.no> - 2017-06-10 22:16 +0200
Re: GPS Again. "HGW, DSc." <HG@....> - 2017-06-11 07:19 +1000
Re: GPS Again. xxein1x1@gmail.com - 2017-06-10 16:11 -0700
Re: GPS Again. Gary Harnagel <hitlong@yahoo.com> - 2017-06-10 18:32 -0700
Re: GPS Again. "HGW..." <hgw@....> - 2017-06-11 14:43 +1000
Re: GPS Again. Gary Harnagel <hitlong@yahoo.com> - 2017-06-13 07:50 -0700
Re: GPS Again. Lolek Atoru <oitiruc@rwuca.oa> - 2017-06-13 20:56 +0000
Re: GPS Again. "HGW..." <hgw@....> - 2017-06-14 09:25 +1000
Re: GPS Again. Gary Harnagel <hitlong@yahoo.com> - 2017-06-13 17:02 -0700
Re: GPS Again. "HGW..." <hgw@....> - 2017-06-14 12:36 +1000
Re: GPS Again. Gary Harnagel <hitlong@yahoo.com> - 2017-06-13 20:04 -0700
Re: GPS Again. moroney@world.std.spaamtrap.com (Michael Moroney) - 2017-06-14 04:43 +0000
Re: GPS Again. "HGW, DSc." <HG@....> - 2017-06-14 20:11 +1000
Re: GPS Again. moroney@world.std.spaamtrap.com (Michael Moroney) - 2017-06-14 14:47 +0000
Re: GPS Again. "Paul B. Andersen" <relativity@paulba.no> - 2017-06-11 22:35 +0200
Re: GPS Again. Serg io <invalid@invalid.com> - 2017-06-11 15:44 -0500
Re: GPS Again. Serg io <invalid@invalid.com> - 2017-06-11 18:03 -0500
Re: GPS Again. Serg io <invalid@invalid.com> - 2017-06-11 19:00 -0500
Re: GPS Again. "HGW..." <hgw@....> - 2017-06-12 11:39 +1000
Re: GPS Again. moroney@world.std.spaamtrap.com (Michael Moroney) - 2017-06-12 02:33 +0000
Re: GPS Again. Tom Roberts <tjroberts137@sbcglobal.net> - 2017-06-11 22:42 -0500
Re: GPS Again. Serg io <invalid@invalid.com> - 2017-06-11 23:27 -0500
Re: GPS Again. jimp@specsol.spam.sux.com - 2017-06-12 04:47 +0000
Re: GPS Again. Serg io <invalid@invalid.com> - 2017-06-12 08:20 -0500
Re: GPS Again. jimp@specsol.spam.sux.com - 2017-06-12 17:18 +0000
Re: GPS Again. Prokaryotic Caspase Homolog <prokaryotic.caspase.homolog@gmail.com> - 2017-06-15 10:06 -0700
Re: GPS Again. Kotovanich Nzerovu <ivhvruo@wovewvw.ev> - 2017-06-15 17:30 +0000
Re: GPS Again. benj <benj@nobody.net> - 2017-06-12 18:15 -0400
Re: GPS Again. jimp@specsol.spam.sux.com - 2017-06-12 22:32 +0000
Re: GPS Again. benj <benj@nobody.net> - 2017-06-12 20:48 -0400
Re: GPS Again. jimp@specsol.spam.sux.com - 2017-06-13 01:52 +0000
Re: GPS Again. benj <benj@nobody.net> - 2017-06-13 19:57 -0400
Re: GPS Again. jimp@specsol.spam.sux.com - 2017-06-14 00:46 +0000
Re: GPS Again. Tom Roberts <tjroberts137@sbcglobal.net> - 2017-06-12 09:58 -0500
Re: GPS Again. Selina Dieter <uiueeits@wlwtwstd.ci> - 2017-06-12 15:08 +0000
Re: GPS Again. Serg io <invalid@invalid.com> - 2017-06-12 10:37 -0500
Re: GPS Again. jimp@specsol.spam.sux.com - 2017-06-12 17:21 +0000
Re: GPS Again. Selina Dieter <uiueeits@wlwtwstd.ci> - 2017-06-12 17:40 +0000
Re: GPS Again. jimp@specsol.spam.sux.com - 2017-06-12 18:05 +0000
Re: GPS Again. Selina Dieter <uiueeits@wlwtwstd.ci> - 2017-06-12 18:19 +0000
Re: GPS Again. jimp@specsol.spam.sux.com - 2017-06-12 19:16 +0000
Re: GPS Again. moroney@world.std.spaamtrap.com (Michael Moroney) - 2017-06-12 19:43 +0000
Re: GPS Again. benj <benj@nobody.net> - 2017-06-12 18:25 -0400
Re: GPS Again. Serg io <invalid@invalid.com> - 2017-06-12 18:45 -0500
Re: GPS Again. "HGW..." <hgw@....> - 2017-06-12 10:35 +1000
Re: GPS Again. Sylvia Else <sylvia@not.at.this.address> - 2017-06-12 11:05 +1000
Re: GPS Again. Serg io <invalid@invalid.com> - 2017-06-11 23:29 -0500
Re: GPS Again. "HGW..." <hgw@....> - 2017-06-12 20:12 +1000
Re: GPS Again. Poutnik <poutnik4nntp@gmail.com> - 2017-06-12 13:54 +0200
Re: GPS Again. Selina Dieter <uiueeits@wlwtwstd.ci> - 2017-06-12 12:47 +0000
Re: GPS Again. "HGW, DSc." <HG@....> - 2017-06-13 04:13 +1000
Re: GPS Again. Sylvia Else <sylvia@not.at.this.address> - 2017-06-13 12:59 +1000
Re: GPS Again. mlwozniak@wp.pl - 2017-06-12 23:03 -0700
Re: GPS Again. "HGW, DSc." <HG@....> - 2017-06-13 04:22 +1000
Re: GPS Again. Sylvia Else <sylvia@not.at.this.address> - 2017-06-13 13:00 +1000
Re: GPS Again. Tom Roberts <tjroberts137@sbcglobal.net> - 2017-06-13 13:32 -0500
Re: GPS Again. "HGW..." <hgw@....> - 2017-06-14 10:09 +1000
Re: GPS Again. "HGW..." <hgw@....> - 2017-06-14 09:34 +1000
Re: GPS Again. Серг ио <invalid@invalid.com> - 2017-06-13 18:42 -0500
Re: GPS Again. "HGW..." <hgw@....> - 2017-06-14 12:40 +1000
Re: GPS Again. moroney@world.std.spaamtrap.com (Michael Moroney) - 2017-06-14 04:06 +0000
Re: GPS Again. mlwozniak@wp.pl - 2017-06-14 01:20 -0700
Re: GPS Again. Sегg iо <invalid@invalid.com> - 2017-06-13 23:19 -0500
Re: GPS Again. Sегg iо <invalid@invalid.com> - 2017-06-13 23:46 -0500
Re: GPS Again. "HGW, DSc." <HG@....> - 2017-06-14 20:07 +1000
Re: GPS Again. Sегg iо <invalid@invalid.com> - 2017-06-14 09:17 -0500
Re: GPS Again. "HGW..." <hgw@....> - 2017-06-17 08:26 +1000
Re: GPS Again. benj <benj@nobody.net> - 2017-06-16 20:40 -0400
Re: GPS Again. Ecembre Abin <umueuu@eibbwaw.ee> - 2017-06-17 08:05 +0000
Re: GPS Again. "HGW, DSc." <HG@....> - 2017-06-17 22:20 +1000
Re: GPS Again. Sегgi о <iinvalid@invalid.com> - 2017-06-17 07:58 -0500
Re: GPS Again. benj <benj@nobody.net> - 2017-06-14 17:06 -0400
Re: GPS Again. "HGW..." <hgw@....> - 2017-05-31 09:58 +1000
Re: GPS Again. "Paul B. Andersen" <relativity@paulba.no> - 2017-05-27 07:36 +0200
Re: GPS Again. "HGW... DSc." <hgw@....> - 2017-05-28 10:57 +1000
Re: GPS Again. Rafael Valls Hidalgo-Gato <rvalls162@gmail.com> - 2017-05-31 07:02 -0700
Re: GPS Again. "HGW..." <hgw@....> - 2017-06-01 09:00 +1000
Re: GPS Again. Odd Bodkin <bodkinodd@gmail.com> - 2017-05-31 23:42 +0000
Re: GPS Again. "HGW..." <hgw@....> - 2017-06-01 19:36 +1000
Re: GPS Again. Gary Harnagel <hitlong@yahoo.com> - 2017-06-01 05:33 -0700
Re: GPS Again. "HGW, DSc." <HG@....> - 2017-06-02 19:51 +1000
Re: GPS Again. Gary Harnagel <hitlong@yahoo.com> - 2017-06-03 05:10 -0700
Re: GPS Again. "HGW..." <hgw@....> - 2017-06-04 08:08 +1000
Re: GPS Again. Gary Harnagel <hitlong@yahoo.com> - 2017-06-03 15:27 -0700
Re: GPS Again. "HGW..." <hgw@....> - 2017-06-04 08:50 +1000
Re: GPS Again. pnalsing@gmail.com - 2017-06-03 19:37 -0700
Re: GPS Again. Poutnik <poutnik4nntp@gmail.com> - 2017-06-04 07:09 +0200
Re: GPS Again. "HGW..." <hgw@....> - 2017-06-04 16:06 +1000
Re: GPS Again. Prudence Youngs <usue@weuem.ge> - 2017-06-04 11:11 +0000
Re: GPS Again. Poutnik <poutnik4nntp@gmail.com> - 2017-06-04 14:23 +0200
Re: GPS Again. Prudence Youngs <usue@weuem.ge> - 2017-06-04 12:33 +0000
Re: GPS Again. moroney@world.std.spaamtrap.com (Michael Moroney) - 2017-06-04 18:17 +0000
Re: GPS Again. Gary Harnagel <hitlong@yahoo.com> - 2017-06-04 05:06 -0700
Re: GPS Again. Prudence Youngs <usue@weuem.ge> - 2017-06-04 12:12 +0000
Re: GPS Again. anne <0140519@gmail.com> - 2017-06-04 05:32 -0700
Re: GPS Again. "HGW..." <hgw@....> - 2017-06-05 08:48 +1000
Re: GPS Again. Gary Harnagel <hitlong@yahoo.com> - 2017-06-04 16:09 -0700
Re: GPS Again. "HGW..." <hgw@....> - 2017-06-05 11:12 +1000
Re: GPS Again. Gary Harnagel <hitlong@yahoo.com> - 2017-06-04 19:24 -0700
Re: GPS Again. "HGW..." <hgw@....> - 2017-06-05 16:38 +1000
Re: GPS Again. Gary Harnagel <hitlong@yahoo.com> - 2017-06-05 04:49 -0700
Re: GPS Again. mlwozniak@wp.pl - 2017-06-05 05:53 -0700
Re: GPS Again. "HGW..." <hgw@....> - 2017-06-06 08:38 +1000
Re: GPS Again. Gary Harnagel <hitlong@yahoo.com> - 2017-06-05 20:30 -0700
Re: GPS Again. Poutnik <poutnik4nntp@gmail.com> - 2017-06-04 15:00 +0200
Re: GPS Again. Prudence Youngs <usue@weuem.ge> - 2017-06-04 11:10 +0000
Re: GPS Again. Odd Bodkin <bodkinodd@gmail.com> - 2017-06-04 13:25 +0000
Re: GPS Again. "HGW..." <hgw@....> - 2017-06-05 08:46 +1000
Re: GPS Again. Odd Bodkin <bodkinodd@gmail.com> - 2017-06-04 23:13 +0000
Re: GPS Again. "HGW..." <hgw@....> - 2017-06-05 11:16 +1000
Re: GPS Again. Odd Bodkin <bodkinodd@gmail.com> - 2017-06-05 09:26 -0500
Re: GPS Again. "HGW..." <hgw@....> - 2017-06-06 08:46 +1000
Re: GPS Again. Odd Bodkin <bodkinodd@gmail.com> - 2017-06-05 23:17 +0000
Re: GPS Again. "HGW..." <hgw@....> - 2017-06-07 10:11 +1000
Re: GPS Again. Odd Bodkin <bodkinodd@gmail.com> - 2017-06-07 03:04 +0000
Re: GPS Again. "HGW..." <hgw@....> - 2017-06-07 14:58 +1000
Re: GPS Again. Odd Bodkin <bodkinodd@gmail.com> - 2017-06-07 12:17 -0500
Re: GPS Again. "HGW..." <hgw@....> - 2017-06-08 09:06 +1000
Re: GPS Again. moroney@world.std.spaamtrap.com (Michael Moroney) - 2017-06-05 00:49 +0000
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