For the marina story, see:
http://www.gpsworld.com/gps/system-challenge/the-hunt-rfi-776
The L1 signal was unintentionally jammed.
John WA4WDL
--------------------------------------------------
From: "Didier Juges" <did...@cox.net>
Sent: Sunday, November 15, 2009 9:55 PM
To: "'Discussion of precise time and frequency measurement'"
<time-nuts@febo.com>
Subject: Re: [time-nuts] The Demise of LORAN (was Re:
Referenceoscillatoraccuracy)
I was shooting from the hip, I thought the DGPS signals were sent at UHF,
but maybe not, but that's not the point. The point is that you can
significantly affect DGPS operation without having to jam the GPS signal
itself.
I found a reference saying the Monterey Bay jammer was jamming the DGPS
station, rather than the DGPS signal. I have not found the original
article
I was looking for about it, but I think I remember that the boaters and
Coast Guards were the most affected, as you should expect because they
rely
on and need the additional accuracy of the DGPS system.
Didier
-----Original Message-----
From: time-nuts-boun...@febo.com
[mailto:time-nuts-boun...@febo.com] On Behalf Of David I. Emery
Sent: Sunday, November 15, 2009 8:30 PM
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] The Demise of LORAN (was Re:
Reference oscillatoraccuracy)
That is the first I've heard of a UHF DGPS correction
transmission
can you provide a frequency and modulation mode ? Most I
know of are
re purposed LF NDBs or similar transmitters in the 200 to 400
KHz or so range that transmit a PSK'd carrier with the DGPS
data at fairly low speed on it.
I have heard of cases of wide area GPS outages noted by
many folks with NON DGPS receivers (DGPS receivers mostly
will just indicate no DGPS available and still show a pretty
good position) that were caused by UHF signals on the L2
frequency... though I am sure there are incidents of
accidental interference to LF or other distribution of DGPS.
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