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)?

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

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

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

Timbo

In message , Tim
writes
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)?

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

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

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

Timbo

The European system is already being deployed, the first satellite is
already up (of course you need at least 4 for a good position),
forgotten the name of the system though..
The Russians have their own system called GLASNOSS and the Chinese have
also started sending up satellites so they have their own version as
well.
--
Regards,

James Christie

"In the beginning the Universe was created. This has made a lot of people very
angry and been widely regarded as a bad move."
- Douglas Adams

In message , James Christie
writes
In message , Tim
writes
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)?

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

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

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

Timbo

The European system is already being deployed, the first satellite is
already up (of course you need at least 4 for a good position),
forgotten the name of the system though..
The Russians have their own system called GLASNOSS and the Chinese have
also started sending up satellites so they have their own version as
well.

********, its GLONASS, I ALWAYS get that the wrong way round......
--
Regards,

James Christie

"In the beginning the Universe was created. This has made a lot of people very
angry and been widely regarded as a bad move."
- Douglas Adams

"James Christie" wrote in message
...

********, its GLONASS, I ALWAYS get that the wrong way round......

Your gonads are inverted???!!! :-)

--
MatSav

James Christie wrote:

The Russians have their own system called GLASNOSS


You have to be joking.

In article ,
TP wrote:
James Christie wrote:

The Russians have their own system called GLASNOSS

You have to be joking.


GLONASS. Can't recall off-hand how many satellites are in the
constellation at the moment, but they've been keeping it topped up.
In general GPS is better for accuracy at low latitudes, GLONASS
better at high latitudes. A high proportion of "GPS" receivers
are actually dual GPS/GLONASS.

--
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 Thu, 23 Sep 2004 22:32:22 UTC, TP wrote:

: James Christie wrote:
:
: The Russians have their own system called GLASNOSS

: You have to be joking.

Maybe he is. I think it's called GLONASS.

Ian

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