10, 2014 1:49 AM
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] WAAS.
Hi,
This is a known problem. It's leakage form the local oscillator (LO) of the
Ky197. The KYa97 has a 10.7 MHz IF and high side local oscillator. So the LO
is 119.9 + 10.7 = 130.6MHz. 12th
On Fri, Jan 10, 2014 at 3:32 AM, Joe Leikhim jleik...@leikhim.com wrote:
Once at St John USVI, I spotted a huge luxury motor yacht anchored with 18
to 20 VHF or UHF fiberglass whip antennas attached top side. Never could
figure why they needed so many.
A Time-Nut's boat?
--
Sanjeev Gupta
One of my clients had exactly that problem with radar detectors in
parked cars interfering with its satellite earth stations. In that
case, the answer was about three years.
Did the FCC actually DO anything about these things ?
Yes, it eventually initiated a rulemaking and
On 1/9/14 12:20 AM, Joe Leikhim wrote:
GPS jamming, intentional or not is pretty serious, and the FCC takes
this seriously, but unless you have some pretty hard evidence they may
not find it.
In my case my most interesting outage was when I lost all GPS while over
the Atlantic ocean between
br...@lloyd.com said:
navigation system that is going up. For that matter, is anyone running one
of the new multi-system receivers? I notice that Garmin is selling them as a
matter of course now. The prevalence of jamming might be the reason why.
Aren't the alternatives using frequencies
On Thu, Jan 9, 2014 at 12:21 PM, Hal Murray hmur...@megapathdsl.net wrote:
br...@lloyd.com said:
navigation system that is going up. For that matter, is anyone running
one
of the new multi-system receivers? I notice that Garmin is selling them
as a
matter of course now. The prevalence
I wonder what the FCC does if it discovers it is another governmental
agency that is doing the jamming?
Probably not much since their charter does not allow them jurisdiction of other
federal agencies.
Your experience reminds me of the time I was on the beach in Key West and a matte black
The latest receivers are surprisingly resilient to GPS jamming.
We tried jamming effects on all sorts of different GPS units ourselves,
and the M12's go out right away for example, while the uBlox units are tough
to jam. The new generation 7 ublox with Glonass etc should be even harder
to
Hi Brian,
Thanks for the fascinating story!
For that matter, is anyone running one of the new multi-system receivers?
I hope to play with Resolution SMT GG which is the Multi-GNSS version of
the Desolution SMT.
What I'm keen to find out is which of the standard GPS diagnostic
software
] On
Behalf Of Brian Lloyd
Sent: Thursday, January 09, 2014 8:47 AM
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] WAAS.
On 1/9/14 12:20 AM, Joe Leikhim wrote:
GPS jamming, intentional or not is pretty serious, and the FCC takes
this seriously, but unless
On 1/9/14 7:53 PM, J. L. Trantham wrote:
I have had loss of GPS position on a 'hand-held' unit (Garmin GPSMAP 396)
when flying into PNS. When I switch to tower frequency (119.9 MHz) the unit
loses its position. I think it is related to some 'spur' related to the #1
Nav/Com (King KY197)
)
From: J. L. Trantham jlt...@att.net
To: 'Discussion of precise time and frequency measurement' time-nuts@febo.com
Sent: Friday, 10 January 2014, 1:53
Subject: Re: [time-nuts] WAAS.
I have had loss of GPS position on a 'hand-held' unit (Garmin GPSMAP 396)
when flying
In this case the timing rcvrs are located all with in a 20km radius with fixed
known surveyed locations. The problem is GPS jamming that happens at random
times. So one what if idea is to use a WAAS enabled rcvr and a yet to be
selected parabolic antenna to point at a given WAAS sat. The
wa1...@att.net said:
In this case the timing rcvrs are located all with in a 20km radius with
fixed known surveyed locations. The problem is GPS jamming that happens at
random times. So one what if idea is to use a WAAS enabled rcvr and a yet
to be selected parabolic antenna to point at a
Hal wrote:
The WAAS satellites don't provide timing info. They provide corrections to
the timing a receiver gets from normal GPS satellites. So if all you can
hear is the WAAS satellites, you won't have any timing info to correct.
I'm confused every time I read about WAAS. Some say the
Hal-
Maybe *I* don't understand the WAAS data stream then. In the case of a
common-view single satellite timing transfer or calibration like is done
every day by NIST, et al., could not a WAAS SVN be used for such an
application? I short, my idea was to use just such a fixed common-view
The ionospheric data provided by the WAAS sat’s is somewhat limited. The longer
the path, the worse the performance. That’s one of the many reasons you get
better survey information from post processed data.
On Jan 8, 2014, at 3:25 AM, Brian, WA1ZMS wa1...@att.net wrote:
In this case the
I thought I had seen something regarding this before, and sure enough here it
is:
http://www.freqelec.com/gps_gnss/waas_for_telecom_wp_5-06.pdf
http://hugofruehauf.com/pdf/24-WAAS_for_Telecom_2003-upd_2011.pdf
http://www.dtic.mil/dtic/tr/fulltext/u2/a485380.pdf
All variations on the same idea -
Ah, so it's really a nuisance alarm problem. Two questions:
1. Is it really a nuisance? Is the holdover adequate to maintain
accuracy of your network?
2. Can the nuisance alarms be eliminated by configuration without
spending money on hardware?
Bill Hawkins
Curiosity question: Are these folks
/divdivFrån: Brian, WA1ZMS
wa1...@att.net /divdivDatum:2014-01-08 09:25 (GMT+01:00)
/divdivTill: Discussion of precise time and frequency measurement
time-nuts@febo.com /divdivRubrik: Re: [time-nuts] WAAS. /divdiv
/divIn this case the timing rcvrs are located all with in a 20km radius
div Originalmeddelande /divdivFrån: Brian, WA1ZMS
wa1...@att.net /divdivDatum:2014-01-08 09:25 (GMT+01:00)
/divdivTill: Discussion of precise time and frequency measurement
time-nuts@febo.com /divdivRubrik: Re: [time-nuts] WAAS. /divdiv
/divIn this case the timing rcvrs
On Wed, Jan 8, 2014 at 12:02 PM, Brian, WA1ZMS wa1...@att.net wrote:
As far as I have seen first-hand, the jamming is short in nature and events
that I saw were from trucks on highways trying to defeat any tracking
systems in the trucks. An FCC enforcement issue here in the US resulted in
one
Thought of or tried ground plane antennas like Trimble choke ring, Zephyr
or similar to attenuate below horizon interference?
On 2014-01-08 01:25, Brian, WA1ZMS wrote:
In this case the timing rcvrs are located all with in a 20km radius with fixed known
surveyed locations. The problem is GPS
Brian, WA1ZMS wrote:
In my case, SW masking of hold-over alarms may be a shorter fix without any
HW fixes.
If you can mask short-duration alarms while still finding out about persistent
ones, then yes, that's probably the most pragmatic solution. What's your
holdover tolerance?
Following
We have a Rb for hold-over that is good for 72hrs per our needs. So we are fine
in that regard.
That said, the vendor of the GPS box is a bit to fast and our equipment is also
in some regards a bit too fast to report a string of alarms when both the main
and hot-standby units go into
Nathaniel wrote:
Following from that, suppose a jammer parks nearby and doesn't leave
in a timely fashion. How long does it take for the FCC to swoop in
(do they swoop? in my mind they do) and find the source?
One of my clients had exactly that problem with radar detectors in
parked cars
Hi,
On 08/01/14 16:33, ziggy9+time-n...@pumpkinbrook.com wrote:
I thought I had seen something regarding this before, and sure enough here it
is:
http://www.freqelec.com/gps_gnss/waas_for_telecom_wp_5-06.pdf
http://hugofruehauf.com/pdf/24-WAAS_for_Telecom_2003-upd_2011.pdf
On Wed, Jan 08, 2014 at 08:09:04PM -0500, Charles Steinmetz wrote:
Nathaniel wrote:
Following from that, suppose a jammer parks nearby and doesn't leave
in a timely fashion. How long does it take for the FCC to swoop in
(do they swoop? in my mind they do) and find the source?
One of my
On 1/8/14 9:06 PM, David I. Emery wrote:
On Wed, Jan 08, 2014 at 08:09:04PM -0500, Charles Steinmetz wrote:
Nathaniel wrote:
Following from that, suppose a jammer parks nearby and doesn't leave
in a timely fashion. How long does it take for the FCC to swoop in
(do they swoop? in my mind they
Brian;
Regarding mobile jammers..
Many years ago I was faced with finding the cause of sporadic
interference to a new 800 MHz trunked LMR system in Miami. This problem
dogged several engineers and myself for months as the customer was
reluctant to make final payment on the $8million system.
Hypothetical question
For a given set of GPS timing grade receivers at multiple locations, is there
any advantage by limiting allowable SVN numbers to only be the WAAS satellites?
-Brian, WA1ZMS/4
iPhone
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Hi
The WAAS sat’s are (in general) going to be long path sat’s. That will give you
more trouble with the ionosphere.
Are the locations of the receivers well surveyed already?
Bob
On Jan 7, 2014, at 8:25 PM, Brian, WA1ZMS wa1...@att.net wrote:
Hypothetical question
For a given set of
It is the receiver, not the satellites, that are WASS enabled.
The WASS differentials are used to correct the ionosphere path lengths.
Michael K7HIL- Sent from my Samsung S4
On Jan 7, 2014 6:07 PM, Bob Camp li...@rtty.us wrote:
Hi
The WAAS sat’s are (in general) going to be long path sat’s.
Brian,
On 2014-01-08 02:25, Brian, WA1ZMS wrote:
Hypothetical question
For a given set of GPS timing grade receivers at multiple locations, is there
any advantage by limiting allowable SVN numbers to only be the WAAS satellites?
Well, if you do common view GPS comparision and is not into
An ION paper by Nagle, et al.
Nagle, J. R., Van Dierendonck, A. J., Hua, Q. D., INMARSAT-3 NAVIGATION
SIGNAL C/A CODE SELECTION AND INTERFERENCE ANALYSIS, NAVIGATION,
Journal of The Institute of Navigation, Vol. 39, No. 4, Winter
1992-1993, pp. 445-462.
Inmarsat-3, the next generation of
Hi Brooke
Maybe I'll drop a line to Hugo to get his comments.
Rob
-Original Message-
From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On
Behalf Of Brooke Clarke
Sent: 20 February 2007 00:45
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] WAAS for Time
Rather than put it on my site, here is the link direct to Zyfer's site.
http://www.zyfer.com/briefings/gps/waas%20for%20t-f%20aps%2010-04.pdf
Rob Kimberley
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Hi Rob:
I'm concerned about using an 18 inch Ku band satellite dish for GPS.
At Ku band a wavelength is about 1 inch so the dish is 18 wavelengths
across.
But at GPS a wavelength is about 8 inches and so the dish is a little
over 2 wavelengths across, a much broader (if any at all) pattern.
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