WRT my sextant comment,  How many pilots or sailors can navigate by ‘shooting the sun/stars’.  They have become dependent on precision navigation systems.

Which of course feeds the thinking by empty suits why do we need lighthouses, buoys, VOR’s and airway beacons because we have the ‘god box’ onboard.  Its old fashioned and uncool.

Interestingly enough there have been enough GPS ‘outages’ that the USNO is once again requiring proficiency in celestial navigation in order to graduate food for thought there.

I was initially speaking about loss of GPS due to natural causes.  In times of international tension attacking a country by denying its ONLY source of precision time transfer would be a particularly effective tactic and you dont even have to damage the satellites themselves.  Just jam L1

As to relying on systems operated by one’s political adversaries that does not seem to be a wise option.

So once again for US’ians time to pick up the phone and put pen to paper and state while the US budget is bloated.  This particular item NEEDS to stay.  Find a vanity construction project and make it disappear instead.  And point out the technical reasons it needs to stay.

Scott

On Aug 12, 2018, at 4:49 PM, Joe Dempster joe.dempster@gmail.com wrote:

I hope that defunding is just a ploy and things will remain on the air.  I
am concerned this is starting to sound like 2010 when DHS/USCG took eLoran
off the air in the states.  This was one of the few things that totally
dismayed me about the Obama administration.

--
Joe Dempster
+1 908 413 2889 (mobile)

Joe Dempster
+1 908 413 2889 (m)

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Hi

Well, if you are worried about L1 jamming, use a receiver that can run on L1/L2/L5 and maybe a few of the other
bands as well. Broadband jammers make really good targets, even for a pretty “dumb” weapon / tracking system.
The more bands they cover, the easier they are to spot.

Broadband jamming really isn’t that big a deal. The GPS signal gets buried in the noise and the GPSDO goes into
holdover. If they can’t track down / eliminate the jammer in 24 hours ….. that’s because there’s a very high level of
other radiation ….Again, the jammer is probably pretty far down the list if this is the case.

So yes, if you are trying to navigate in an active war zone, things can get a bit weird. I doubt that any of us will be
trying to come up with timing for our bench under those conditions.

Bob

An interesting interaction between the near Earth CMEs and the geomagnetic
field leads to some complex results also.  Googling Carrington Event will
give some interesting details.  The geomagnetic and geoelectric field
monitoring at observatories of CME interaction and associated earth
electrical currents is fascinating.

Is there any numeric code that will model the Newtonian trajectory and CME
geometry given input velocity and mass parameters?  These are CME velocity
and mass parameters estimated now and I’ve seen Goddard NASA laboratory
animations which show CME magnetohydrodynamics (?)  combined with the
estimated  interplanetary trajectories and CME topology and always wondered
if there was, for example, accessible MATLAB or python codes available to
create such estimates.    The NASA animations are found on YouTube.

On Mon, Aug 13, 2018 at 15:05 jimlux jimlux@earthlink.net wrote:

--
Dr. Geophysics
http://dr.geophysics.googlepages.com

On Mon, Aug 13, 2018 at 8:52 AM Peter Laws plaws0@gmail.com wrote:

Still looking for this.  Most of the "OMG IF WWV GOES AWAY MILLIONS
WILL DIE" posts (elsewhere, not here ... quite ...) are the type of
hysteria that is usually reserved for, I don't know, the EMP folks.
:-)

One of the responses to my initial message pointed out that the
effects of solar flares and CMEs take a while to get from Sol to Sol
III and don't arrive all at once, so potentially all GNSS spacecraft
could be affected.

Since then, I've been poking around for papers on the effect
(observed, potential, theoretical) of these events on the Navstar or
other GNSS constellations but am not having much luck.  I assume it's
because I'm not putting the right magic incantation into the google
machine.

Anyone got some cites?  Looking for the effect of solar flares and
CMEs on the spacecraft themselves and not how the GNSSs can be used to
measure the effects on the ionosphere, etc (those seem plentiful).
IOW, I'm curious about the resiliency of the systems to solar events.

I did note that at the time of the 1989 solar event that took out a
lot of Hydro Quebec's grid, only the "Block I" experimental GPS "SVs"
were in orbit.  Well, maybe a couple of the later ones - the
operational constellation started launching about a month before that
flare.

As I said initially, I'll be sad if WWV* goes away but it won't affect
my life in any measurable way that I can see.  I mean, other than the
mantle clock slowly losing time.

--
Peter Laws | N5UWY | plaws plaws net | Travel by Train!

Hi

There most certainly was a lot of “stuff” in orbit by that time. If there was
a mass die off of satellites, you would not have to look hard to find out about
it.

Bob

On Thu, Aug 30, 2018 at 12:59 PM Bob kb8tq kb8tq@n1k.org wrote:

Probably not as many as there are 3 decades later, but of course.
Satellite service (any type of satellite) is much more likely to be
human-caued.

But here (and in other fora) the concern is that WWV Must Be
Maintained in order to save us from being late for coffee if another
event on the level of the Carrington Event takes out every single GNSS
spacecraft in orbit.  But I can't find anything on the effect of that
sort of solar event on satellites.  Almost as if, maybe, satellite
operators were aware of solar physics and planned for this sort of
event.

And I still haven't seen any coherent argument in favor of keeping WWV
that doesn't involve nostalgia or (perhaps) unfounded fear.

--
Peter Laws | N5UWY | plaws plaws net | Travel by Train!

The port of Long Beach CA was jammed wrt GPS for several months by a malfunctioning 29.95 TV preamplifier on a boat.

GPS was completely unusable when this unsuspecting guy was watching TV on his boat.

He had quite the surprise when the coasties with guns showed up.

The fact is civillian GPS Is trivial to jam and jammers can be bought ‘under the counter’ at any truckstop along with illlegal linear amplifiers.

On Aug 30, 2018, at 12:58 PM, Peter Laws plaws0@gmail.com wrote:

On Mon, Aug 13, 2018 at 8:52 AM Peter Laws plaws0@gmail.com wrote:

Still looking for this.  Most of the "OMG IF WWV GOES AWAY MILLIONS
WILL DIE" posts (elsewhere, not here ... quite ...) are the type of
hysteria that is usually reserved for, I don't know, the EMP folks.
:-)

One of the responses to my initial message pointed out that the
effects of solar flares and CMEs take a while to get from Sol to Sol
III and don't arrive all at once, so potentially all GNSS spacecraft
could be affected.

Since then, I've been poking around for papers on the effect
(observed, potential, theoretical) of these events on the Navstar or
other GNSS constellations but am not having much luck.  I assume it's
because I'm not putting the right magic incantation into the google
machine.

Anyone got some cites?  Looking for the effect of solar flares and
CMEs on the spacecraft themselves and not how the GNSSs can be used to
measure the effects on the ionosphere, etc (those seem plentiful).
IOW, I'm curious about the resiliency of the systems to solar events.

I did note that at the time of the 1989 solar event that took out a
lot of Hydro Quebec's grid, only the "Block I" experimental GPS "SVs"
were in orbit.  Well, maybe a couple of the later ones - the
operational constellation started launching about a month before that
flare.

As I said initially, I'll be sad if WWV* goes away but it won't affect
my life in any measurable way that I can see.  I mean, other than the
mantle clock slowly losing time.

--
Peter Laws | N5UWY | plaws plaws net | Travel by Train!

time-nuts mailing list -- time-nuts@lists.febo.com
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and follow the instructions there.

Hi

When infastructure GPS does get jammed these days that source gets tracked down a lot faster
than a month or so. Anything that goes on for more than a day gets booted up pretty high
pretty fast. Indeed I’ve been in the middle of that more than I would have wished to be …..

The same sort of RFI issues that take out GPS from a TV preamp  can equally well take out WWVB or WWV.
With WWVB, there are a lot of 60KHz switching power supplies out there to create problems. There is nothing
unique about any of these services in terms of being jam immune.

The bigger issue with any of them is spoofing. A proper GPSDO will go into holdover when RFI jammed. I would
assume the same would be true of a fancy WWVB device. I’m not at all sure that’s true of a real WWVB standard,
they haven’t been for sale new for a really long time. If your time source is in holdover, you can go out and track down
the issue. If it simply locks to the new signal …. not so much.

There is a subtle distinction in some of this. Newer systems do indeed want time. Older systems were generally after
frequency. The only WWVB standards I’ve seen were aimed at frequency (and frequency holdover) rather than time and
time holdover. Getting reasonable (1 to 10 ppb) frequency from WWVB is a very different task than getting the sort of time
that modern systems are after.

Bob

Hi Bob:

I would disagree in that ease of jamming/spoofing is strongly related to wavelength.  That's because antenna efficiency
goes down as the size of the antenna gets smaller than 1/4 wave.
So, it's easy to make a GPS jammer (1,100 to 1,600MHz) since a 1/4 wavelength is a few inches, something that  you can
hold in your hand.
It's harder to make a WWV jammer (.5, 5, 10, 15, 20 MHz) since a 1/4 wavelength in in the range of  500 to 12 feet,
something that can be mounted on a vehicle for the higher frequencies.
But it's extremely hard to make a jammer for WWVB (60 kHz) where a 1/4wavelength is over 4,000 feet.  This means an
antenna that can be vehicle mounted will be very inefficient. Note this also means that it's extremely hard to make a
Loran-C jammer.  Note that the WWVB and LORAN-C transmitters run very high power and the antennas are massive.

This also means that if someone makes a WWVB simulator for their house the signal at the next door neighbor's house is
probably going to be too small to effect their clocks.

PS. Some decades ago I maintained a beacon transmitter "LAH" on 175 kHz where the rules for unlicensed operation limited
the input power to 1 Watt and total antenna length to 50 feet.  Under these conditions the effective radiated power
might be 2 milliwatts, orders of magnitude less if a portable system.
http://www.auroralchorus.com/pli/1750meter_antennas.pdf

--
Have Fun,

Brooke Clarke, N6GCE
https://www.PRC68.com
https://www.end2partygovernment.com/2012Issues.html
axioms:

1. The extent to which you can fix or improve something will be limited by how well you understand how it works.
2. Everybody, with no exceptions, holds false beliefs.

-------- Original Message --------

Hi

Well, designing jammers on a public forum is an “interesting” thing to do…..

With WWVB, you are fine with a “near field” solution. You don’t need something that propagates for
miles and miles. The other thing you have in your favor is that coming up with a KW at 60 KHz is
quite easy. All those 60 KHz switchers we complain about … there’s your dirt cheap source of parts.

The next part of the “solution” is to feed your signal into the local power grid. Your switcher is happy
with a low impedance load. The power line looks fairly low impedance at 60 KHz. It goes the RF and
out and about it flows. Indeed it works pretty well over a good chunk of ground. At least as good as your
typical GPS jammer and no more expensive. Been there end done all that, though not for a WWVB jammer.

Bob