On Sat, 20 Mar 2004 05:20:01 GMT, Guy Alcala
wrote:
Ed Rasimus wrote:
You're adding a parameter here, the need to pre-program the missile.
That's a step beyond the initial proposition of "look-to-kill" linkage
between the helmet field of view and the missile's regard. I've always
been a bit cautious, nay even skeptical about marketing brochure
claims and operational capability.
From an article in the May 22nd, 2000 AvLeak,
pg. 28. I forget who's speaking, but IIRR it was an Air Force type, maybe the
program manager:
"'We are embarking on putting a high off-boresight capability into AMRAAM.'"
The keyword here, I think, is "embarking".
"Two Phase Program. Initially, only the missile software will be modified,
allowing AMRAAM to engage a target throughout the FOV of the fighter's radar,
including about 70 degrees off boresight. The current software limits the
missile to about 25 degrees off boresight. The enhancement should be available
next year [i.e. 2001].
That pretty much describes the state-of-the-art I'm familiar with.
Going to 70 degrees off boresight is a lot of angular range, but it
still hasn't reached the wing line.
"The second phase, still unfunded, would involve upgrading the fighter's
software and enable AMRAAM to engage targets behind the shooting a/c. Data on
the target would be provided by a second fighter through so-called 'third-party
cuing,' [through Link-16],. After launch, updates continue to be relayed
through back and sidelobes of the firer's radar. The upgrade follows the
ongoing improvement to the missile's warhead, fuse and motor."
Here's where things begin to get interesting. First, the data fusion
aspect--integrating sensor info from multiple players to provide a
full 360 degree field of presentation. Conceptually it's been around
for 15 years or more (since my days with ATF at Northrop), but it is
elusive.
What is problematic is the ability to provide jam-proof links between
the players and the desire to keep emissions low in a stealthy
environment. Radar is the default primary sensor, but it really lights
up the emitter so while one side wants to keep increasing power and
scan limits, the other side wants to go LPI and use small, infrequent
low-power pinging for data which is then adjusted by trend sensing
software to keep the picture current. Compex to say the least.
Then, the "updates relayed through back and sidelobes of the firer's
radar" is a perfect example of the incompatibility of the two
competing concepts. Getting back and sidelobes powerful enough for
guidance is in direct conflict with minimizing or eliminating back and
sidelobes for stealth.
The AGM-78 Standard ARM had the first generation program for launch
capability to strike targets behind the launch aircraft.
In the Standard's case, I've read Weasel anecdotes which suggest that making a
180 pretty much decreased the remaining energy to zero, the Standard not being
the most maneuverable missile on the planet. I've been given some info of the
kind of sustained maneuverability the P4 is capable of, and if you'd like I'll
be happy to share it with you. Suffice it to say (here), it's far better.
The Standard usually didn't turn left or right, but took off and
turned upward. Then from high altitude it used the potential energy to
maintain manuever on the downward track to the target. That gave it
considerable range to the rear, but as I said, very little
confirmation of effectiveness other than the occasional signal kill at
an approximately correct elapsed time from launch.
A lot has to happen in very short time and in a very dynamic scenario.
Sure does. And computers just get faster, smaller and cheaper all the time.
We appear to be entering the era of missiles like the ones 007 had on his gyro
in "You Only Live Twice."
Spot on. It is allowing amazing things to happen.
Ed Rasimus
Fighter Pilot (USAF-Ret)
"When Thunder Rolled"
Smithsonian Institution Press
ISBN #1-58834-103-8
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