In article ,
Tim wrote:
On Thu, 23 Sep 2004 15:57:55 +0000, Peter Masson wrote:

(Can GPS identify which line the train is on if adjoining
platforms are different lengths?)

Not with any certainty.

Of course, what happens if the Pentagon decided to turn off GPS for
civilian use without warning (which they've always stated they have the
right to do)?

Galileo. And, indeed, Glonass (which we have now - and most receivers are
dual GPS/Glonass)

Or worse, they have a war and introduce deliberate errors into the system
designed to confuse the enemy?

Galileo. And, indeed, Glonass.

I can see it now on the 9:24 from Tonbridge: "We will shortly be arriving
at Copenhagen, please mind the step"

Galileo. And, indeed, Glonass.

I know that Europe is going to deploy it's own GPS sats, but I don't know
when that will be.

Galileo, not GPS. A much better system (it'll have to be if it's to do a
fraction of what they're wanting it to do). The programme is being pushed
ahead hard and should be delivering in the next 3-5 years (depends how
fast the constellation goes up, which in turn depends on who'll be
launching). In the meantime there's Glonass, which the Pentagon certainly
doesn't have a veto over.

--
Andy Breen ~ Interplanetary Scintillation Research Group
http://users.aber.ac.uk/azb/
"Time has stopped, says the Black Lion clock
and eternity has begun" (Dylan Thomas)

In article ,
ANDREW ROBERT BREEN wrote:

/GPS-replacement/

Galileo, not GPS. A much better system (it'll have to be if it's to do a
fraction of what they're wanting it to do). The programme is being pushed
ahead hard and should be delivering in the next 3-5 years (depends how

Should have added - first satellite is up, more coming. Not checked in the
last few months on the launch schedule for the rest of it, and the best
accuracy will depend on other stuff in the pipeline - but that's for
things like landing airliners under Galileo control..

--
Andy Breen ~ Interplanetary Scintillation Research Group
http://users.aber.ac.uk/azb/
"Who dies with the most toys wins" (Gary Barnes)

ANDREW ROBERT BREEN wrote:

In article ,
ANDREW ROBERT BREEN wrote:

/GPS-replacement/

Galileo, not GPS. A much better system (it'll have to be if it's to do a
fraction of what they're wanting it to do). The programme is being pushed
ahead hard and should be delivering in the next 3-5 years (depends how

Should have added - first satellite is up, more coming. Not checked in the
last few months on the launch schedule for the rest of it, and the best
accuracy will depend on other stuff in the pipeline - but that's for
things like landing airliners under Galileo control..

I though Surrey Satellite Technology and, IIRC, Astrium had only recently
got contracts to build some development satellites. As it is, they've only
just agreed the frequencies they're going to use as the USAians were
complaining that the main signal would sit right on their military band and
they wouldn't be able to locally degrade Galileo without doing the same to
their own military.

Matthew
--
Matthew Wild Tel.: +44 (0)1235 445173
URL http://www.wdc.rl.ac.uk/
World Data Centre - Solar-Terrestrial Physics, Chilton
Rutherford Appleton Laboratory, Chilton, Didcot, Oxon, OX11 0QX

In article ,
Matthew Wild wrote:
ANDREW ROBERT BREEN wrote:
Galileo, not GPS. A much better system (it'll have to be if it's to do a
fraction of what they're wanting it to do). The programme is being pushed
ahead hard and should be delivering in the next 3-5 years (depends how

Should have added - first satellite is up, more coming. Not checked in the
last few months on the launch schedule for the rest of it, and the best

I though Surrey Satellite Technology and, IIRC, Astrium had only recently
got contracts to build some development satellites. As it is, they've only
just agreed the frequencies they're going to use as the USAians were
complaining that the main signal would sit right on their military band and
they wouldn't be able to locally degrade Galileo without doing the same to
their own military.

You've got the better information there - I must have mixed up something
else with a Galileo launch.

Aha! Got it. First structual model of the Galileo satellite rolled out,
first launches planned for next year:

http://www.esa.int/esaNA/SEMVDX0XDYD_index_0.html

Have to say that fits in better with where I thought they were up to than
launched-already, which did puzzle me.

--
Andy Breen ~ Interplanetary Scintillation Research Group
http://users.aber.ac.uk/azb/
"Time has stopped, says the Black Lion clock
and eternity has begun" (Dylan Thomas)

On Fri, 24 Sep 2004 10:37:17 +0100, Matthew Wild
said:

the USAians were
complaining that the main signal would sit right on their military band and
they wouldn't be able to locally degrade Galileo without doing the same to
their own military.

Sounds like a feature, not a bug.

--
David Cantrell | http://www.cantrell.org.uk/david