"Blunkett u-turn on data privacy plans"

[Fearghas McKay]

At 14:37 +0000 3/3/03, Roland Perry wrote:

>
> >Don't forget specialised GPS receiving
> >stations are used to track minute movements (down to the order of 100
> >microns) in e.g. earthquake research.
>
>I have never heard of such a thing. Most claim even differential GPS is
>only good to a metre.

it is differential movement that is being measured not absolute
positioning. You have two antenna and you measure where thwy are in
relation to each other. Similar tricks have been used on ships for years as
it allows the replacement of gyroscopes for measuring roll and yaw.

	f