"Tim" wrote in message .. .
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?

Never mind that , GPS is easily blocked by obstructions such as trees ,
embankments , bridges etc. And as for tunnels... Still , on the bright side
that means LU won't be using it for the doors anytime soon

B2003