I seem to remember a recent 'jamming' trial off the east coast of England that didn't kill the GPS but did shift the position of the ships involved - certainly enough to get them aground or to hit something if they weren't paying attention. I think one showed up inland - which should have been suspicious! Sorry, cannot remember the reference but was mentioned in GPS World, I think.
Paul Reeves G8GJA -----Original Message----- From: gary [mailto:[email protected]] Sent: 15 December 2011 23:45 To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] "The GPS navigation is the weakest point," I've talked to the GPS jammers at Nellis and have seen their gear. They don't spoof but just jam. The gear is totally COTS. Some Marconi signal generator that can generate white noise at the two GPS frequencies. They have omni or directional antennas. They have an old Russian jammer on hand, but the Marconi works a lot better. I've been jammed by them. It is interesting in that the GPS just suddenly dies. That is, it seems to track given some noise, but you hit a point where it suddenly gives up. It is the only time I've seen no satellites shown on the display. It wouldn't surprise me if a Growler could spoof a GPS, but I have no hard evidence that it can. I'm in agreement with they just jammed everything and the thing ran out of fuel. I have a FOIA somewhere on a Predator crash. With LOS, it just orbits. In the case of this Predator, it orbited into a mountain near Creech AFB. On 12/15/2011 3:18 PM, Chris Albertson wrote: > I bet this drone contains no technology that is not exportable. Of > course they had to think about a crash. > > I also bet it had an inertial nav system as backup to the GPS. But > and this is the key to all backups. You have to know the primary is > failed. When you jam GPS the smart way is not to over power it with > white noise but to first transmit an IDENTICAL signal. Then very > slowly move your stronger signal away from "truth" until it is sending > a false signal. This way the receiver does not know it is being > jammed. No I did not just think of this, it's what "everyone" does. > But why then if the INS and GPS disagree was there not an alarm? It > was likely a low-cost INS that needed periodic updates from a GPS > > I would not rule out that they simply made the drone fly into a big > fishing net and dropped it with a parachute in a kind of controlled > mid air collision. Heck the US used to capture film cam falling from > space with big nets > > Chris Albertson > Redondo Beach, California > > _______________________________________________ > time-nuts mailing list -- [email protected] To unsubscribe, go to > https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. > _______________________________________________ time-nuts mailing list -- [email protected] To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. This email, including any attachment, is a confidential communication intended solely for the use of the individual or entity to whom it is addressed. It contains information which is private and may be proprietary or covered by legal professional privilege. If you have received this email in error, please notify the sender upon receipt, and immediately delete it from your system. Anything contained in this email that is not connected with the businesses of this company is neither endorsed by nor is the liability of this company. Whilst we have taken reasonable precautions to ensure that any attachment to this email has been swept for viruses, we cannot accept liability for any damage sustained as a result of software viruses, and would advise that you carry out your own virus checks before opening any attachment. _______________________________________________ time-nuts mailing list -- [email protected] To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
