"Signal jamming a factor in future wars, general says"

In article ,
Paul J. Adam wrote:
In message , W. D. Allen Sr.
writes
Gee, now why didn't they think of the possibility of GPS system jamming
twenty years ago when they invented it? Do you really think that was
overlooked?

Let's split the difference and say it got lost somewhere along the way.
(Otherwise, why would CCM against GPS jammers be a profitable business,
if the system was inherently resistant?)

Some creative Russian printed up some ACME GPS Jamming System
brochures and took SH for some of his money ?



--
Al Dykes
-----------
adykes at p a n i x . c o m

In message , Al Dykes
writes
In article ,
Paul J. Adam wrote:
Let's split the difference and say it got lost somewhere along the way.
(Otherwise, why would CCM against GPS jammers be a profitable business,
if the system was inherently resistant?)

Some creative Russian printed up some ACME GPS Jamming System
brochures and took SH for some of his money ?

Elements of that. Basic GPS systems, civilian and some military, are
very easily sent berserk by low jamming powers. Less basic systems are
more resistant, increasing (for rising input cost) to very jam-proof
systems that are extremely difficult to lock out.

GPS jamming is a real problem. It has real solutions and it's not a
surprise. (And it's harder to do than the doomsayers would claim, just
as it's more of a problem than some like to admit)

--
He thinks too much: such men are dangerous.
Julius Caesar I:2

Paul J. Adam MainBoxatjrwlynch[dot]demon{dot}co(.)uk

"Paul J. Adam" wrote in message ...
In message , Al Dykes
writes
In article ,
Paul J. Adam wrote:
Let's split the difference and say it got lost somewhere along the way.
(Otherwise, why would CCM against GPS jammers be a profitable business,
if the system was inherently resistant?)

Some creative Russian printed up some ACME GPS Jamming System
brochures and took SH for some of his money ?

Elements of that. Basic GPS systems, civilian and some military, are
very easily sent berserk by low jamming powers. Less basic systems are
more resistant, increasing (for rising input cost) to very jam-proof
systems that are extremely difficult to lock out.

GPS jamming is a real problem. It has real solutions and it's not a
surprise. (And it's harder to do than the doomsayers would claim, just
as it's more of a problem than some like to admit)

The higher end systems would appear to have highly directional 'phased
array' antena that can exclude the jaming signal by locking onto the
satelite directly based on both satelite signal and known maps of
satelite position. A jammer must thus be as high as possible
(preferably in line with between the satelite ) to get energy into the
sidelobes of the antena.

Low cost solid state acceleromters and inertial guidence systems will
give many munitions a inertial guidence system that will takeover as
soon as effective jamming is detected which is likely to be only near
the target. There are indeed wind corrected bombs that cost perhaps
double that of a GPS bomb but loose only a little in accuracy. On top
of that simple infrared imaging systems based on the same sensors now
used in highend cars add even more accuracy than GPS is capable of.
At best jammer will only be able to degrade the accuracy slightly
while forcing up the price of the munition slighly or even increasing
it by forcing the bomber to add a simple terminal homing system.

GPS jammers (noise generators) are the standard tools nowadays.
Obviously, the weak satellite signal could be shutdown quite easily.
It's not a top notch, cool technology anymore, just usual (and
probably boring) stuff.

See, http://www.noisecom.com/content/Prod.../GPS7500_5.pdf

Russian regards,
Yuri

In article ,
(Yuri Tregubov) wrote:

GPS jammers (noise generators) are the standard tools nowadays.
Obviously, the weak satellite signal could be shutdown quite easily.

Not so obviously.

The directionality of RF, along with the inverse-square law, make it
*much* harder to jam a source that's effectively "behind" the incoming
munitions than you'd think. The jammers have to be quite high powered,
and are therefore pretty easy to find and disable (along with the
problem of keeping the jammers powered for days or weeks at a time).

It's not a top notch, cool technology anymore, just usual (and
probably boring) stuff.

See, http://www.noisecom.com/content/Prod.../GPS7500_5.pdf

You might note, for example, that the testing device above is used to
determine if *internal* RF noise interferes with GPS function (if a cell
phone or car mounted GPS is degraded by RF in the same vehicle).

It takes a lot of power to do anything to a GPS signal at anything like
a reasonable range.

--
cirby at cfl.rr.com

Remember: Objects in rearview mirror may be hallucinations.
Slam on brakes accordingly.

Don't know is it true or not, but have read that hobbyist level
nonsophisticated 1W jammer shuts down GPS devices in an area of
hundred kilometres.

The ECM warfare is very well developed field, so it's not a problem to
jam a weak signal at all. Of course, the GPS could be done more or
less jam proof, but it costs a lot of money and hence not practical
for wide use.

There's no difference in jamming radar/comm/GPS, all of them are the
"RF devices", use the same basic principles and communication media.

Russian regards,
Yuri

In article ,
(Yuri Tregubov) wrote:

Don't know is it true or not, but have read that hobbyist level
nonsophisticated 1W jammer shuts down GPS devices in an area of
hundred kilometres.

It's not true. The strength of a one watt signal just plain isn't
enough for such a thing to be true.

Whoever told you this knows *nothing* about RF other than the term
"watt."

--
cirby at cfl.rr.com

Remember: Objects in rearview mirror may be hallucinations.
Slam on brakes accordingly.

Is standard EMC equipment (pods/ground) applicable for GPS jamming ?
How unique are the GPS signals in comparison to "normal" radar/comm ?

Yuri