In article ,
"Brian G" writes:
Gizmo wrote:
"Brian G" wrote in message
...
BTW, if you have a mobile phone, you can be tracked by GPS to within
a few metres - even with it turned off.

Incorrect.
We can track a mobile, but not that accurately ... and it has to be
switched on.

That's not the information that I have read, but I stand to be corrected.
As far as I have found out, even when switched off, a mobile phone emits a
carrier wave that can be detected.

If it's on but idle, it can be `tracked' by the timing-advance method, but
this a) has nothing to do with GPS (GPS involves signals sent _from_
satellites, _to_ special-purpose receivers, that's all) and b) can be wildly
inaccurate in less-than-perfect circumstances. GPS isn't a tracking system.

There are websites you can sign up to to look at this stuff. I tried it out
once, and was promptly told that the phone dangling from my belt was actually
in a back street 14 miles distant, and I promptly decided that I wasn't going
to take that on as a service.

If your phone is switched off, it isn't trackable by any means I'm aware of.
--
SAm.