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BBC News Blunder



 
 
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  #11  
Old July 30th 17, 03:43 PM posted to uk.telecom.broadband,uk.tech.digital-tv,alt.satellite.tv.europe
Tony van der Hoff
external usenet poster
 
Posts: 1
Default BBC News Blunder

On 30/07/17 15:39, NY wrote:

Yes. I think GPS satellites are still in orbits about the centre of the
earth but at a lower altitude so they move relative to the earth's
surface, so a give point on the earth will see various satellites
rising, travelling across the sky and setting at different times of day.
I'm not sure how long a given satellite is above the horizon, or whether
all satellites are at the same altitude and so have the same orbit time.
I imagine that GPS satellites have orbits that are at various angles to
the equator.


He
https://en.wikipedia.org/wiki/Global...4goldenSML.gif
  #12  
Old July 30th 17, 04:45 PM posted to uk.telecom.broadband,uk.tech.digital-tv,alt.satellite.tv.europe
Bill Wright[_3_]
external usenet poster
 
Posts: 1,756
Default BBC News Blunder

On 30/07/2017 11:28, Java Jive wrote:
"Powys man gets broadband via satellite over Africa"

http://www.bbc.co.uk/news/uk-wales-mid-wales-40745533

"[It is the same satellite companies like Sky use to broadcast their
TV signal and] they are positioned above the equator to maximise
coverage."

Oh dear! Actually, they are positioned over the equator because that
is the only place you can obtain a geo-stationary orbit, enabling
fixed dishes to work. Satellites that aren't in geo-stationary orbit
require movable dishes that can track an orbit to communicate with
them ...

http://www.macfh.co.uk/JavaJive/Audi...sisClarke.html


They've rewritten it now. But it's still largely ********.

Bill
  #13  
Old July 30th 17, 04:47 PM posted to uk.telecom.broadband,uk.tech.digital-tv,alt.satellite.tv.europe
Bill Wright[_3_]
external usenet poster
 
Posts: 1,756
Default BBC News Blunder

On 30/07/2017 14:33, 7 wrote:

Could you not have a satellite in a geostationary orbit above another line
of latitude than the equator


No because Earth is a slight doughnut shape with the bulge through
the equator, and the Moon is also orbiting around the equator
which means orbits other than equator are not stationary or stable.


********

Bill
  #14  
Old July 30th 17, 04:48 PM posted to uk.telecom.broadband,uk.tech.digital-tv,alt.satellite.tv.europe
Bill Wright[_3_]
external usenet poster
 
Posts: 1,756
Default BBC News Blunder

On 30/07/2017 15:39, NY wrote:

Yes. I think GPS satellites are still in orbits about the centre of the
earth but at a lower altitude so they move relative to the earth's
surface, so a give point on the earth will see various satellites
rising, travelling across the sky and setting at different times of day.
I'm not sure how long a given satellite is above the horizon, or whether
all satellites are at the same altitude and so have the same orbit time.
I imagine that GPS satellites have orbits that are at various angles to
the equator.


Weather satellites orbit over the poles.

Bill
  #15  
Old July 30th 17, 04:49 PM posted to uk.telecom.broadband,uk.tech.digital-tv,alt.satellite.tv.europe
NY
external usenet poster
 
Posts: 1,124
Default BBC News Blunder

"Bill Wright" wrote in message
news
On 30/07/2017 14:33, 7 wrote:

Could you not have a satellite in a geostationary orbit above another
line
of latitude than the equator


No because Earth is a slight doughnut shape with the bulge through
the equator, and the Moon is also orbiting around the equator
which means orbits other than equator are not stationary or stable.


********


Are you saying that what 7 said is ********, or that your ******** are "a
slight doughnut shape with the bulge through the equator"? :-)

  #16  
Old July 30th 17, 05:01 PM posted to uk.telecom.broadband,uk.tech.digital-tv,alt.satellite.tv.europe
charles[_2_]
external usenet poster
 
Posts: 559
Default BBC News Blunder

In article ,
AnthonyL wrote:
On Sun, 30 Jul 2017 11:28:58 +0100, Java Jive
wrote:


"Powys man gets broadband via satellite over Africa"

http://www.bbc.co.uk/news/uk-wales-mid-wales-40745533

"[It is the same satellite companies like Sky use to broadcast their
TV signal and] they are positioned above the equator to maximise
coverage."

Oh dear! Actually, they are positioned over the equator because that
is the only place you can obtain a geo-stationary orbit, enabling
fixed dishes to work. Satellites that aren't in geo-stationary orbit
require movable dishes that can track an orbit to communicate with
them ...

http://www.macfh.co.uk/JavaJive/Audi...sisClarke.html


What would the BBC know about programme transmission? It's like
expecting BT to understand the internet.


even worse, the BBC hasn't had transmitters for about 20 years.

--
from KT24 in Surrey, England
  #17  
Old July 30th 17, 05:38 PM posted to uk.telecom.broadband,uk.tech.digital-tv,alt.satellite.tv.europe
Graham.[_12_]
external usenet poster
 
Posts: 389
Default BBC News Blunder

On Sun, 30 Jul 2017 17:49:33 +0100, "NY" wrote:

"Bill Wright" wrote in message
news
On 30/07/2017 14:33, 7 wrote:

Could you not have a satellite in a geostationary orbit above another
line
of latitude than the equator

No because Earth is a slight doughnut shape with the bulge through
the equator, and the Moon is also orbiting around the equator
which means orbits other than equator are not stationary or stable.


********


Are you saying that what 7 said is ********, or that your ******** are "a
slight doughnut shape with the bulge through the equator"? :-)


The doughnut bit is largely the correct, it's the moon orbiting the
equator that's ********, it orbits the ecliptic plane.
--

Graham.
%Profound_observation%
  #19  
Old July 30th 17, 06:03 PM posted to uk.telecom.broadband,uk.tech.digital-tv,alt.satellite.tv.europe
Alan White[_3_]
external usenet poster
 
Posts: 71
Default BBC News Blunder

On Sun, 30 Jul 2017 15:39:17 +0100, "NY" wrote:

Yes. I think GPS satellites are still in orbits about the centre of the
earth but at a lower altitude so they move relative to the earth's surface,
so a give point on the earth will see various satellites rising, travelling
across the sky and setting at different times of day. I'm not sure how long
a given satellite is above the horizon, or whether all satellites are at the
same altitude and so have the same orbit time. I imagine that GPS satellites
have orbits that are at various angles to the equator.


The GPS satellites are in 55 degree, semi-sidereal orbits. This means
that their orbits are inclined at 55 degrees to the equator and that the
orbital period is 11h 58m. The last time I checked there were 27 active
satellites. Reception from three satellites is required for a 2D fix,
four satellites for a 3D fix. The horizontal position will have a
typical accuracy of better than 15 metres anywhere on the globe for 95%
of the time over a 30 day period. The 3D position altitude error is
roughly twice the horizontal error.

--
Alan White
Mozilla Firefox and Forte Agent.
By Loch Long, twenty-eight miles NW of Glasgow, Scotland.
Webcam and weather:- http://windycroft.co.uk/weather
  #20  
Old July 30th 17, 08:22 PM posted to uk.telecom.broadband,uk.tech.digital-tv,alt.satellite.tv.europe
Robin[_8_]
external usenet poster
 
Posts: 428
Default BBC News Blunder

On 30/07/2017 18:38, Graham. wrote:


The doughnut bit is largely the correct, it's the moon orbiting the
equator that's ********, it orbits the ecliptic plane.

I think you dropped "at roughly 5 degrees to" from in front of "the
ecliptic plane". (That's why solar eclipses don't happen every lunar
month. Most "new moons" are above or below the ecliptic.)

--
Robin
reply-to address is (intended to be) valid
 




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