[Discuss] GPS feature in cellphones?

[Richard Pieri]

Rich Braun wrote:
> But anyone
> who has ever fiddled with a handheld GPS or wifi-enabled device knows how much
> of a power-suck those technologies are.  Just because Ed Snowden found a
> document that claims otherwise doesn't mean it's true.

You're assuming that the GPS receiver in the device has anything to do
with it. All that a device needs to do is send a chirp every few
minutes. This requires very little power. A single tower can calculate
fairly accurate locations from the chirps (Doppler effect); two towers
can triangulate precise locations.

This is basic radio. There's nothing fancy here.

> The average common-crook can get away from the cops by turning off his
> cellphone and driving faster/cleverer than they do.  Count on it.  Maybe by
> 2020 that won't be true.

One word: Stingray.

-- 
Rich P.