Agreed. Furthermore, a GPS jammer is VERY hard to locate because the signal levels are so low.
An effective LORAN jammer could easily be DF'd with a foot sized loop and tuning capacitor resonating at 100KHz, diode detector, and a set of headphones. It would be IMPOSSIBLE to hide. If a LORAN transmitter were destroyed by a terrorist team, a backup could be in operation in hours. A damaged GPS system could easily take many months or even years to fix. -John ================ > And all the GPS goodness can easily be disabled by a missile and a > near nuclear burst or a portable handheld jammer at the airport. > The portable handheld jammer is a very real threat to GPS due to the > signal levels from the satellite. > > Now they are trying to revive a miswired SVN and add it to the network. > > It is very hard to jam the LORAN signal without a high power jammer. > If a LORAN station is taken out by enemy action, it is not > unreasonable to rebuild or replace it. > > GPS is just too fragile to be heavily relied on. > > I know that we do it every day, but, you need to have a backup > navigation system. > > LORAN is time proven to be functional and the technology is in place > on a number of platforms to utilize it. > > > 73 > Glenn > WB4UIV > ETCS(SS) USN Retired (Electronic Navigation) > > At 10:21 PM 11/14/2009, Francesco Ledda wrote: >>LORAN is a good back up, but it has problems and limitations. Navigating >>next to a storm can overwhelm the receiver and make it unusable. The >> LORAN >>system doesn't have a build in accuracy degradation system like GPS(RAIM >> - >>receiver autonomous integrity monitoring), and this make LORAN unfit to >> fly >>Non-Vertical Guidance approaches. GPS with its accurate positioning, fast >>update rate and WAAS make is an awesome aircraft navigation system that >> can >>replace almost all NAVAIDS including ILS. Today with GPS, we can fly in >>instrument conditions from take off to landing without ever tuning any >>external NAVAID; not even INS can't do that. It is pretty amazing to me! >> >> >> >> >> >> >>-----Original Message----- >>From: [email protected] [mailto:[email protected]]on >>Behalf Of Hal Murray >>Sent: Saturday, November 14, 2009 7:13 PM >>To: Discussion of precise time and frequency measurement >>Subject: Re: [time-nuts] The Demise of LORAN (was Re: Reference >>oscillator accuracy) >> >> >> >> > I've read and heard from this forum as well as a number of other >> > sources that GPS can be easily jammed. What makes GPS so vulnerable? >> > How can it be jammed? >> >>The signal is very very very weak. The question is not how can it be >>jammed, >>but rather how can you find the signal at all. >> >>There was a recent message here reporting on the 5th harmonic of a small >> 315 >>MHz radio link wiping out GPS for a 1/2 mile: >> http://www.mail-archive.com/[email protected]/msg22033.html >> >>Here is a good story: >> Unjamming a Coast Harbor >> James R. Clynch, Andrew A. Parker, George Badger, >> Wilbur R. Vincent, Paul McGill, Richard W. Adler >> GPS World, Jan 1, 2003 >> http://www.gpsworld.com/gps/system-challenge/the-hunt-rfi-776 >> >> >> >>-- >>These are my opinions, not necessarily my employer's. I hate spam. >> >> >> >> >>_______________________________________________ >>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. >> >> >> >> >>E-mail message checked by Spyware Doctor (6.0.0.386) >>Database version: 5.13700 >>http://www.pctools.com/en/spyware-doctor-antivirus/ >> >> >> >> >> >>E-mail message checked by Spyware Doctor (6.0.0.386) >>Database version: 5.13700 >>http://www.pctools.com/en/spyware-doctor-antivirus/ >> >>_______________________________________________ >>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. > > _______________________________________________ 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.
