jim bell <jimbell@pacifier.com> writes:
On a related issue, GPS (global-positioning system) contains a de-accurizing mis-feature called S/A, which adds a little error to the location as detected by a receiver. Ostensibly, it was added so that this could be turned on in wartime, to deny the enemy the ability to make 10-meter fixes. Turns out that it was kept on all the time, probably because if it WASN'T it would become politically impossible to de-accurize the system even in wartime
Two funny rumors: 1. Supposedly the DoD users of GPS have access to the accurate positioning information at all times. (Not sure how this works - the accurate data is encrypted?) During the Iraq war in '93 they didn't have enough equipment to take advantage of this, so they turned off the S/A and gave everyone (including the military users) accurate GPS on commercially available GPS eq. Then they turned it back on. 2. The DoD is doing a study right now on how to make GPS useless to the enemy at wartime. I think figuring out a way to turn off A/S and getting accurage GPS on commercial equipment at all times would make a nifty Cypherpunks project - if it really involves breaking some encryption. --- Dr.Dimitri Vulis KOTM Brighton Beach Boardwalk BBS, Forest Hills, N.Y.: +1-718-261-2013, 14.4Kbps