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: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com]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/time-nuts@febo.com/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 -- time-nuts@febo.com 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 -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
