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