In article ,
Wayne.B wrote:

On Sat, 17 Jul 2010 14:35:36 +0100, (Steve Firth)
wrote:

You seem to have been attempting to claim that GPS cannot be jammed

Incorrect. I am claiming that it is unlikely that GPS is being jammed
by the Cuban government.

Not to dis Wayne, but MANY Governments that are NOT Allies with the USA,
have purchased GPS Jamming Technology, from the Russians, for the simple
Paranoid Reason, that they can turn it ON, and it will keep some of our
Lower Tech GPS Guided Munitions from hitting their intended Targets,
should we feel the need to go to War with them.... Most of the more
Modern Guided Munitions now use other Primary Guidance Systems, and GPS
is only a Backup Slave System, that can be set to be compared with the
Primary System.
These same Governments, test these Systems regularly... Our own
Government DOES protect MANY of our most important Federal AREAS, using
similar Technologies, for the same reasons. GPS is great, but it is NOT
the One Size Fits ALL Munition Aiming System....

--
Bruce in alaska
add path after fast to reply

Bruce in alaska wrote:

Most of the more Modern Guided Munitions now use other Primary Guidance
Systems

Great Random CaPitalisation tHere.

FWIW, a great many Old Guided Munitions use other Primary gUiDancE
sySteMs.

On Sun, 18 Jul 2010 12:19:23 -0800, Bruce in alaska
wrote:

Not to dis Wayne, but MANY Governments that are NOT Allies with the USA,
have purchased GPS Jamming Technology, from the Russians,

It was never my point that GPS could not be jammed. My point was,
and is, that such jamming would by necessity be relatively short range
because of the microwave frequencies involved. The only exception
would be some sort of systemic jamming that originated within the
satellites themselves. It's my understanding that jamming of that
sort would affect all users.

Wayne.B wrote:

On Sun, 18 Jul 2010 12:19:23 -0800, Bruce in alaska
wrote:

Not to dis Wayne, but MANY Governments that are NOT Allies with the USA,
have purchased GPS Jamming Technology, from the Russians,

It was never my point that GPS could not be jammed. My point was,
and is, that such jamming would by necessity be relatively short range
because of the microwave frequencies involved. The only exception
would be some sort of systemic jamming that originated within the
satellites themselves. It's my understanding that jamming of that
sort would affect all users.

You've already been given details of two types of jamming and SA which
is not jamming. However at present you seem to be keener on jamming your
head up your arse and avoiding admitting the fact.

"Wayne R." wrote in message
...
On Sun, 18 Jul 2010 09:56:35 -0400, "JR" wrote
(with clarity & insight):

"Wayne R." wrote in message
. ..
On Sat, 17 Jul 2010 20:25:22 -0400, "JR" wrote
(with clarity & insight):

Washington DC and Fort Hood in upstate NY are just
two places I have personal knowlege of where GPS is
munged for security purposes.
Regards,
JR

I've been using plain ol' GPS devices in & around DC for years with no
issues. What am I missing?

I have a Ram Mount in my GMC Yukon we use as a travel car, On this
mount I place a laptop and more recentlya Netbook computer on the Ram
and use MS Streets & Trips with a USB "puck" as the GPS
receiver/antenna. On the many trips south from Pa to Fla as I use the
DC Beltway and with the GPS in tracking mode it becomes "lost". The
1st time this happened I thought it was the unit itself and told it
to recalculate the route from my current location. It couldnt
determine my current location until we were merging back onto I-95.
It simply didn't know where it was. Weather was not a factor (clear
skies) nor was it a lack of GPS signal (it still showed as tracking 8
sats).
This "problem" is repeatable 100% of the time on various trips thru
the area.

Similarly, During a trip for my daughters wedding and subsequent trips to
Ft
Hood, when approching base housing the same thing happens. Every time.
When I asked my son-in-law about it he would only say "Yeah, kinda neat
huh?"
In conversations with my youngest daughters soon-to-be-husband who was
home on leave from Jihadistan, he indicated that even there a few sites
are
so protected.

Now, in northern NJ and northern Wi there are coverage gaps where the GPS
can't resolve it's location, but these are a different situation as the
unit tells
me it can't find itself and why.
Not so with the DC & Ft. Hood issues.
Regards,
JR

I've found places where I've seen repeatable problems with one type of
receiver but not another. (Sometimes problems come & go, and in those
circumstances I've attributed it to constellation/reflection
variations.)

I've spent a lot of time near the White House, Pentagon, Ft. Meade,
Langley, etc., in DC without any loss of lock - some of the places
that seem most likely to have constant jamming?

When your receiver "tells me it can't find itself and why", what does
it say?

Wayne, the receiver will tell me GPS signal not available (usually weather
related), or will indicate not enough Sats
to resolve position. And it will display how many sats it "sees".

With the DC and Ft Hood issues it says nothing.
It just doesn't work.

Regards,
JR

On Mon, 19 Jul 2010 01:42:33 GMT, (patric albutat)
wrote:

So how exactly are we going to create superior charts in regions with
no GPS coverage? Or what use would these charts be to a sailor trying
to navigate a tricky coast without sat nav to give him his position?

Just where are these areas without coverage? Hint: the G in GPS stands
for Global. It's like taxes: everywhere.

Casady

On Sun, 18 Jul 2010 20:19:22 -0500, Richard Casady
wrote:

Just where are these areas without coverage? Hint: the G in GPS stands
for Global. It's like taxes: everywhere.

Apparently there is this conspiracy theory that "someone" is jamming
GPS signals near the coast of Cuba. There is plenty of evidence that
GPS normally works just fine in that area but when people run aground
it is convenient for the ego to have some alternative explanation.

In article ,
(Wayne.B) wrote:

On Sun, 18 Jul 2010 12:19:23 -0800, Bruce in alaska
wrote:

Not to dis Wayne, but MANY Governments that are NOT Allies with the USA,
have purchased GPS Jamming Technology, from the Russians,

It was never my point that GPS could not be jammed. My point was,
and is, that such jamming would by necessity be relatively short range
because of the microwave frequencies involved. The only exception
would be some sort of systemic jamming that originated within the
satellites themselves. It's my understanding that jamming of that
sort would affect all users.


So how exactly are we going to create superior charts in regions with
no GPS coverage? Or what use would these charts be to a sailor trying
to navigate a tricky coast without sat nav to give him his position?

Better get out Lecky's Wrinkles in Practical Navigation, hmm?

Richard Casady wrote:

On Mon, 19 Jul 2010 01:42:33 GMT, (patric albutat)
wrote:

So how exactly are we going to create superior charts in regions with
no GPS coverage? Or what use would these charts be to a sailor trying
to navigate a tricky coast without sat nav to give him his position?

Just where are these areas without coverage?


http://waas.stanford.edu/~wwu/papers...itch_stu95.pdf

http://waas.stanford.edu/~wwu/papers...F/SeoIES08.pdf

http://www.agu.org/pubs/crossref/200...RS003066.shtml

http://www.fly-low.com/features02/gpsdenial.html

https://www.fbo.gov/index?s=opportun...f11c050aeb be
7682bc9ba408a&tab=core&_cview=1

http://www.aviationkb.com/Uwe/Forum....Interference-T
esting-711-reporting

Note that the published radius of jamming by the USG is 180 - 400 nm
(reported for both Maryland and China Lake) something that Wayne refuses
to acknowledge as he repeats that jamming isn't possible over a large
area.

Presumably the NOTAMS stating that jamming was occuring over a wide area
of sea off Cornwall previously posted doesn't mean anything to Wayne
because it's happening somewhere foreign.

Hint: the G in GPS stands for Global. It's like taxes: everywhere.

Then there's the World Series ... so that according to you involves
everyone in the world? It doesn't even involve a significant fraction of
the world's nations. Does Universal Studios involve the entire Universe?

(Steve Firth) wrote in news:1jlv6sr.1b9ejr91nd0q9uN%%
:

Richard Casady wrote:

On Mon, 19 Jul 2010 01:42:33 GMT, (patric albutat)
wrote:

So how exactly are we going to create superior charts in regions with
no GPS coverage? Or what use would these charts be to a sailor trying
to navigate a tricky coast without sat nav to give him his position?


I guess it had to come......No GPS, no way to fix your position...