On Fri, Jun 6, 2014 at 11:56 AM, Bill Bogstad <bogs...@pobox.com> wrote:
> 4. GPS can be done passively by anyone anywhere, while cell tower > triangulation requires endpoints that transmit (and as a result > identify themselves.) > I think that #4 is particularly interesting. > ​Depends what you mean by "passive". Tower triangulation does not require cooperation of the device being tracked, just correlation of its registration chirps, but doesn't let the device know its location. GPS does not require transmission for the device to compute the device's location (Navigation display), but requires a transmission to have anyone else see it (GPS tracking devices, E911). -- Bill Ricker bill.n1...@gmail.com https://www.linkedin.com/in/n1vux _______________________________________________ Discuss mailing list Discuss@blu.org http://lists.blu.org/mailman/listinfo/discuss