On Mon, 28 Jun 2004, Major Variola (ret) wrote:
A GPS receiver doesn't broadcast its location. GPS works purely by analyzing the signals received from satellites. This is probably a design goal for military use, as well as a consequence of power requirements.
Yes. But a jammer will draw a Hellfire.
A $50 jammer for a $500,000 missile. Sounds like a fair trade to me. ;)
It seems that for CDMA or WCDMA phones the location service is defined in terms of messages on the normal network layer, see a Google search for "position determination service order".
Yes its cheaper and allowed (for now) to triangulate (to what, 100m?) using physics; but GPS will become cheaper and cheaper.
Which is good, because once the adversary starts relying exclusively on GPS and lets the other monitoring systems decay, we have easier way to "deny that service" from our handhelds. Physics is more difficult to cheat than chips.