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
I live 20 miles south of San Francisco airport. It's common to see a 747
size plane flying low nearby as they head for the landing queue.
My GPS antennas/receivers are not located in great places. They fade out
occasionally. Some times are longer than others and such, but short dropouts
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 -
It is much more likely that the fade out is due to the changing satellite
geometry. Some of them come into view and other go out of view. If your
antenna site is not good there might be times where only a few are in view
or at low elevation. If there is multi path off a plane it would last
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
Hi Brian!
Hmmm... should I finish the thread before commenting...
The scenario has been discussed on the list before. There are publications from
Zyfer (fei) on Waas timing with a fixed dish antenna. There is also a
Fenton(Novatel) patent.
--
Björn
div Originalmeddelande
Guys-
Thanks for the inputs and the mention of FEI and related patents. I thought the
idea was not new but did not remember the details.
As for some answers:
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
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
On 1/6/2014 2:13 PM, Giuseppe Marullo wrote:
/I would like to know the specs for this attenuator, especially the
maximum frequency, if any good folk has a ballpark idea...
I was not able to locate any info about it./
I too have one, bought cheaply a couple of years ago on eBay. I tested its
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
Hi Alberto it is quite interesting to continue that test with no attenuator
but the shells of the coax plugs connected together. I would guess with the
gear you have the resultant would be at least 120dB downbut this is
not the case for all signal generators! The result is usually
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
On 12 December 2013 19:29, Robert Atkinson robert8...@yahoo.co.uk wrote:
I know Goldmine would not sell duff stuff knowingly, but the Engineering
Sample label worries me a little. Often this is indicates a non-functioning
item for display or trial fit purposes. Then again it maybe not. I
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
They have a page about it... it´s very convoluted (at least for me, for
whom english is not the first language). It boils to we ship
internationally but only for a short list of countries (mine not
included, unfortunately):
http://www.goldmine-elec-products.com/Testimonials.asp
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.
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