On Feb 16, 4:50*pm, "W. D. Allen" wrote:
"...Perhaps the time has come to put the Navy in charge of all joint
electronic warfare activities...."

Now it can be told...

In 1966 the North Vietnamese with their Russian instructors began shooting
down U.S. aircraft over NVN. Someone in the Navy had the wisdom and
foresight to have on hand 1,000 ALQ-51 deception repeaters originally
dedicated to aircraft protection during execution of the Navy portion of the
SIOP.
They weren't all for SIOP airplanes - and it's not a question of
wisdom and foresight - The USAF had a very active ECM program as
well. All their bombers carried huge batteries of jammers and about a
half ton of chaff, with dedicated receivers for detection of threats,
and dedicated system managers to run them.
The USAF had also been procuring podded jammers through the QRC (Quick
Reaction Contract) program. More on this later.

The Air Force, with bigger airplanes with more electric power
available, went in for large, powerful Noise Jammers, which would
blank out any weaker signals (Like returning blips, which are very
weak) coming into the radar's antenna. Since the reception pattern of
a radar antenna isn't simply where it's pointed, but also includes
sidelobes and backlobes, a strong signal can blot out a huge sector of
the radar's coverage. (Unless they lower the gain (Turn down the
volume) of the receiver to isolate the jamming transmitter,s azimuth -
but if they do that, they lose any weaker blips from non-jamming
airplanes.
These systems work well against Early Warning and GCI systems,
but not so well against weapons control radars - since they blatently
broadcast their Azimuth and Elevation angles (but not range) to the
receiver. If you're lucky, and can shoot enough watts into an
antenna,
you can either burn out the amplifiers in the receiver, or, if the
receiver has self-protection circuits (Most do) force the radar to
automatically shut down. (And a big radar takes from 5-15 minutes to
bring back on line if this happens. That's a long time with airplanes
moving at 8-10 miles/minute)

The Navy, with smaller airplanes and less electricity available, went
in for Deception Jammers. These are very sophisticated in concept,
automatically listening to, and analyzing the characteristics of an
incoming radar, and putting out pulses of its own that, hopefully,
will fool the automatic tracking circuits in a fire control radar
(Deception jammers work best against dedicated tracking radars.) and
make it point somewhere else. Two things to remember here - the only
work well against automatically tracking radars, and they are only
really effective against fire control radars looking at that
particular airplane.


Those ALQ-51s were rounded up from all over the globe (some were found in
Antarctica), refurbished, and sent to Southeast Asia for installation in
carrier aircraft. Meanwhile the Air Force was compelled to use ALQ-76 pod
noise jammers, which the Navy considered little more than tracking beacons..
In fact, USAF found it necessary to ask the Navy for fifty of the ALQ-51s
for their RF-101 recce aircraft that were flying solo over NVN.

And it was discovered that, against SA-2s (And, later, SA-3s) that,
once the Pod formations were developed, which blanked out a volume of
the sky that made very unlikey for an SA-2 launched into it to hit one
of the 4 airplanes in that volume, the Air Force noise jammer solution
worked much better.
The problem is, the Navy through both necessity (small airplanes, not
much electricity) and mirror-imaging, (Thinking that the Bad Guys were
doing the same things that they were, in this case, building
sophisticated automatic tracking systems) built jammers that worked
fairly well at fooling the automatic systems.

But the Soviets (And, hence, their clients) didn't do that.
Early Soviet SAMs didn't use automatically tracking conical scan or
monopulse trackers. They used a pair of overlapping pulse radars, one
searching in azimuth, and one in elevation, on slightly different
frequencies, so that they didn't interfere with each other, and both
reporting their angle and range information. The tracking wsas
actually done by 3 guys in the radar van, one using a handwheel to
hold a marker over the Azimuth blip, one over the Elevation blip, and
another over the combined range blips. This gave the fire control
system a smoother track than an autmatic system, was easier to make
and maintain, and, inadvertently, negated most of the Navy's clever
deception techniques. A pair of eyes with a human brain behind them
is unexcelled at recognizing patterns, and pulling out information
from a seemingly worthless hash. It didn't take long for the tracking
opertors to learn which of the returns coming from an airplane
carrying a Deception Jammer was real, and which were the false
signals.
The noise jammers with their stronger signals and wider frequency
ranges (Which would cover both the Az and El radars of an SA-2,
usually), used singly, would pinpoint an individual airplane in
Azimuth and Elevation, but block out range infomration.
This allowed the shooters to guide their missile, which used a
collision course (make the target's bearing to the missile constant)
approach to make it likely that the missile would get close enough to
the target for its fuze to activate. And an SA-2 had a big warhead -
the fuze would activate about 100 yards out.
This turned the USAF away from using noise jammers on fighters -
until some clever folks at AFSD (The Air Force Systems Division)
figured out that if you put noise jammers on avery airplane in a
flight, and put the airplanes in the proper relation with each other,
the combined jamming signals would blank out a large volume, and that
a missile fired into that volume was unlikely to come close enough to
an airplane to fuze.

Electronic warfare is an occult and complex discipline that doesn't go bang,
has no tailhook and won't go Mach 2+. It's damn hard to push for black boxes
when knuckle draggers want more boom for the buck. They have to learn the
hard way they can't haul their bomb load to the target before they recognize
they need electronic protection as well as missile protection, bullet
protection, etc.

That's true, in a lot of ways, but we've also reached a point where we
don't need as many dedicated assets - We've come a long way at making
our passive systems (Elint receivers and such) smarter and more able
to make it possible to avoid threats, and at making our transmitters
(Which are largely a measure of last resort, since if you transmit,
you tell everybody where you are) more powerful, more economical in
their use of electricity, and smarter, (Used to be that deception
"False Target" generators could only analyze a pulse after it had been
received, so the first target in line was the real one.
(You get a bunch of tranmitters weaving and dodging past each other,
and it gets a bit more difficult to sort out who is who).
Now, the jammer will map the radar's characteristics and make its
pulses wherever it wants to - the false target generator on an EA-6B
or B-52 can white out a scope with individual blips forced into
sidelobes and backlobes.
Stealth airplanes, with much reduced signatures, and hence, detection
ranges, don't benefit from onboard transmitters.
And, with modern satellite elint and photint, it's hard to spring a
radar from a surprise location.
That all being said - there's not a lot of public visibility for
electronic warfare. It perks away, in its own small corner of the
budget, and nobody ever hears about it until some slighted Congressman
comissions a GAO report to criticize a particular program.
(Which leads the Press to leap after something that they can't
understand, being fed soundbites from others who can't, or won't
understand, and who have some axe to grind.)


EW test question: How did Halsey know to send Air Force P-38s to knock
Admiral Yamamoto out of the sky in the South Pacific during WWII?

SIGINT, of course.

The Old Crows know!
Even better - how did we map out the Soviet's Tall King air defence
radar network without direct photo coverage, and the Sovs going silent
whenever the ELINT airplanes were flying around?

--
Pete Stickney