I read in the New Scientist today the satellites required for GPS calculations are getting old. Something like 24 satellites are required to make reasonably accurate calculations. Currently there are around 30 up there but a number are going to fail within two years and bring the numbers down towards 24.
The American Airforce apparently has difficulty building and launching new satellites.
I wonder if this is a bit of scare mongering by the American government in the hope of some other countries contributing towards the cost of the GPS system.
From University of Nottingham source:
GPS Status Summary September 2008
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19 sats were past design life
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15 sats were past pre-launch mean life estimate (MLE)
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18 sats were one component away from nav failure
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8 sats were one component away from bus failure.
Whoops!
GPS Modernisation Schedule
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Second civil signal L2C
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Designed to meet commercial / scientific needs
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Higher accuracy through ionospheric correction
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1st launch: Sep 2006 (IIR-M); 24 satellites: ~2016
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Third civil signal L5
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Designed to meet demanding requirements for safety-of-life
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1st launch: Mar 2009 (IIR-M / IIF); 24 satellites: ~2018
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Fourth civil signal “L1C”
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Designed with partners for GNSS interoperability
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Begins with Block III
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1st launch: ~2014; 24 satellites: ~2021
"Galileo:In orbit validation. 4 operational satellites and ground infrastructure.
Full operational capability 2013. 26 operational satellites and complete ground infrastructure."
They say it will be more accurate and have better reliability than GPS.
Would it prove a point if the original image came from NASA?
I'm a little dubious of Galileo being finished by 2013... its taken them two years to put 4 birds up - I'm not confident they can do another 2 0 in the remaining 4 years.
hey look , iam a fairly basic kind of guy.
very basic on the computer.
Should i go and unfold sum cash for GT31 or not.
