Question about the F-22 and it's radar.

"John Cook" wrote in message
...

OK this is from memory... and the sources are not strictly 'official'.

I had heard some rumours that the F-35 and F-22 AESA antennae will be
merged because the MMIC's from the F-35 will be retrofitted to the
F-22's ( they are very expensive and larger.)

The number of MMIC's may also be the same in both aircraft to make a
common 'cheap' AESA antennae (1200 IIRC).

The whole avionics suite of the F-22 is now obsolete, and will cost
another $3.5 Billion to 'upgrade' thats the cut from the $11.7 Billion
thats been bandied about.

Do you have anything to support that contention? There is a bit of a
difference between wanting to improve the computers during the spiral
development process and claiming that the "whole avionics suite is
*obsolete*", isn't there?


Just the official reports!!, Lockheed has only purchased enough
processors for 155 F-22's because there out of production, the demand
for Air to ground operations has increased the demand on processing
power, something the original processors are not quite upto hence the
_need_ for the 'upgrade'.

Let's see, 155 out of a possible total buy of some 269 aircraft, or a more
likely buy of 200-220, would seem to indicate that the first few *years* of
production are covered. Nor has it been conclusively demonstrated that these
processors are incapable of handling the aircraft's air-to-ground strike
needs during it's initial gestation; more in the form of not being able to
handle the *ultimate* (post spiral) capability that is envisioned.


So the processors are obsolete, (too old)... the Avionic architecture
needs to be replaced before the F-22 can become the F/A-22 because the
present system is based on the old processors and rewriting the code
is pointless on an obsolete system, that would only support half of
the F-22 fleet

You appear to be reading quite a lot into this situation that has not been
clearly stated. The F/A-22, when it first enters into frontline operational
service, will be capable of conducting precision ground strike operations,
with the existing systems. It is desired that the system be enhanced through
its lifetime, hence that $11 billion dollar cost, which includes
enhancements to its ISR capabilities (and one would suspect that is where
the enhanced radar is goinfg to be of the most value), its AA capabilities,
etc.


They have to go with a more COTS based system (similar to, if not the
same as the JSF), which they are working on now, for fielding in (very
optomisticlly) in 2007.

A simple analogy for you, the old 486 computer still works, but when I
wanted to run XP on it the demands of the system increased to the
point where it was useless to try, and you couldn't buy a 486
processor anywhere to support it.

I call that an 'obsolete system', it worked great running win 98.

Now the Raptor can't run the software to do its air to ground mission
for the same reasons what would you call it?. "processor
challenged???"

"Can't run the software" to do the air-to-ground mission? Odd, as the USAF
claims that at present, "The F/A-22 also has an inherent air-to-surface
capability." It can already lug a couple of JDAM's. So how does that even
*require* an optimized ground mapping radar to allow it to strike ground
targets with significant precision?




Out of curiousity, why do you have this visceral hatred of the F/A-22?
Does
it perhaps stem from the fact that you know your own nation can never
afford
it, or what?

I don't hate it, I just think its not worth the money, if it had been
half the price and worked as advertised I would be impressed.
As it is the price is $150M and development is not mature, production
has started, How would you describe the F-22 process?.

LOL! By your definition, no aircraft would ever enter service, as
"development is not mature". I guess you have kind of missed out on the
*continuing* development of the F-15, F-16, and F/A-18, huh? I'd describe it
as about par for the course, especially when viewed against contemporaries
like the Typhoon and Raptor, which are also entering service while
development continues. You really need to get your head out of the WWII era
in terms of fighter development--heck, even before that, as we saw with how
both the P-47 and P-51 gestated (recall the original P-51's were purchased
and produced with less-than-optimal engines, to boot).


Its not a model that every industry is adopting is it.

Looks an awful lot like the same model the Europeans are using, based upon
where they are with Rafale and Typhoon.


I do not doubt that Australia can't afford it, however its looking
increasing likely that the US may join us in that.

I think you can probably count on seeing that "Silver Bullet" force enter
into service...oh, that's right, you are the guy who can't grasp the
viability of that approach, being so firmly wedded to your purely
Lanchesterian model of attritionary combat and all...

Brooks




Brooks


Normally a program this far into production can't be cancelled, but
this program seems to be trying real hard...

The JSF seems (at least so far) to be much more aware of getting
development right first, then moving onto production. (and it doesn't
need the F-22 SMURFS:-))

Cheers



John Cook

Any spelling mistakes/grammatic errors are there purely to annoy. All
opinions are mine, not TAFE's however much they beg me for them.

Email Address :-
Spam trap - please remove (trousers) to email me
Eurofighter Website :- http://www.eurofighter-typhoon.co.uk


John Cook

Any spelling mistakes/grammatic errors are there purely to annoy. All
opinions are mine, not TAFE's however much they beg me for them.

Email Address :-
Spam trap - please remove (trousers) to email me
Eurofighter Website :- http://www.eurofighter-typhoon.co.uk

The whole avionics suite of the F-22 is now obsolete, and will cost
another $3.5 Billion to 'upgrade' thats the cut from the $11.7 Billion
thats been bandied about.

Do you have anything to support that contention? There is a bit of a
difference between wanting to improve the computers during the spiral
development process and claiming that the "whole avionics suite is
*obsolete*", isn't there?

I quote the GAO-04-597T report directly

"The basic mission of the F/A-22, initially focused on air-to-air
dominance,has changed to include a significantly greater emphasis on
attacking ground targets. To accomplish this expanded mission, the
Air Force will need additional investments to develop and expand
air-to-ground attack capabilities for the F/A-22. Moreover, the
efforts to expand its capability will also add risks to an already
challenged program. To accommodate planned changes will also require a
new computer architecture and processor to replace the current less
capable ones."


Now thats hardly ambiguous is it.....



Let's see, 155 out of a possible total buy of some 269 aircraft, or a more
likely buy of 200-220, would seem to indicate that the first few *years* of
production are covered. Nor has it been conclusively demonstrated that these
processors are incapable of handling the aircraft's air-to-ground strike
needs during it's initial gestation; more in the form of not being able to
handle the *ultimate* (post spiral) capability that is envisioned.


Conclusivly demonstrated!!!!, it can't demonstrate stability yet

The Glabal Strike Ehanced program is slated to start in 2011, thats
when the Raptors system architecture is officially obsolete, the
Global strike Basic is due (with current cpu architecture + systems)
in 2007(read end of development cycle for the old stuff), one might
well ask is 2007 too ambitious for a system that still a tiny bit
'buggy', Thats four years of use from your 'its not obsolete its
proccessor challenge' system. providing its reliable enough to pass
the review.....

I quote again the GAO-04-597T report directly


"The stability and performance of F/A-22 avionics has been a major
problem causing delays in the completion of developmental testing and
the start of IOT&E. Because the F/A-22 avionics encountered frequent
shutdowns over the last few years, many test flights were delayed. As
a result, the Air Force Operational Test and Evaluation Center wanted
assurances that the avionics would work before it was willing to start
the IOT&E program. It established a requirement for a 20-hour
performance metric that was to be demonstrated before IOT&E would
begin. This metric was subsequently changed to a 5-hour metric that
included additional types of failures, and it became the Defense
Acquisition Board’s criterion to start IOT&E. In turn, Congress
included the new metric, known as Mean Time Between Avionics Anomaly
or MTBAA, in the National Defense Authorization Act for Fiscal Year
2004.5 As of January 2004, the Air Force had not been able to
demonstrate that the avionics could meet either of these criteria.
Testing as of January 2004 showed the program had achieved 2.7 hours—
54 percent of the 5-hour stability requirement to begin IOT&E. While
the Air Force has not been able to meet the new criteria, major
failures, resulting in a complete shutdown of the avionics system,
have significantly diminished. These failures are occurring only about
once every 25 hours on average. This is the result of a substantial
effort on the part of the Air Force and the contractor to identify and
fix problems that led to the instability in the F/A-22 avionics
software. However, less serious failures are still occurring
frequently."



Now the Raptor can't run the software to do its air to ground mission
for the same reasons what would you call it?. "processor
challenged???"

"Can't run the software" to do the air-to-ground mission? Odd, as the USAF
claims that at present, "The F/A-22 also has an inherent air-to-surface
capability." It can already lug a couple of JDAM's. So how does that even
*require* an optimized ground mapping radar to allow it to strike ground
targets with significant precision?


Dropping a couple of JDAMS whohooooo!!!,
Cutting edge that... well worth the money of investing in a system
thats equivelent of a couple of cray supercomputers.

one wonders what there using that processing power for?. must be a
very nice graphical interface....


what the USAF have stated they want is, but cant have because of the
limitations of the system are :-

2011
Improved radar
capabilities to seek and destroy advanced surface-to-air missile
systems and integrate additional air-to-ground
weapons.

2013
Increased capability to suppress or
destroy the full range of air defenses and improve speed and
accuracy of targeting.

2015
Capability for full intelligence, surveillance, and reconnaissance
integration for increased target sets and lethality.


Out of curiousity, why do you have this visceral hatred of the F/A-22?
Does
it perhaps stem from the fact that you know your own nation can never
afford
it, or what?

I don't hate it, I just think its not worth the money, if it had been
half the price and worked as advertised I would be impressed.
As it is the price is $150M and development is not mature, production
has started, How would you describe the F-22 process?.

LOL! By your definition, no aircraft would ever enter service, as
"development is not mature". I guess you have kind of missed out on the
*continuing* development of the F-15, F-16, and F/A-18, huh? I'd describe it
as about par for the course, especially when viewed against contemporaries
like the Typhoon and Raptor,

Difference is they have demonstrated their requirements and have been
accepted, now they are in production.

compare the F-22 which is in production and hasn't demonstrated it

Do you see the difference?.

I'll ask you again How would you describe they F-22 process??

If 10 is a perfect development program, and 1 is an utter fiasco that
results in over priced, marginalised product thats ripe to be
cancelled, whats the Raptors score?

which are also entering service while
development continues. You really need to get your head out of the WWII era
in terms of fighter development--heck, even before that, as we saw with how
both the P-47 and P-51 gestated (recall the original P-51's were purchased
and produced with less-than-optimal engines, to boot).


Its not a model that every industry is adopting is it.

Looks an awful lot like the same model the Europeans are using, based upon
where they are with Rafale and Typhoon.

Yes the Typhoons processors are old, but they work as advertised now
and are in production - tranche 2 models are being negotiated with
the updated systems included, as per the original plans, with a
federated architecture its relatively simple in comparison.


I do not doubt that Australia can't afford it, however its looking
increasing likely that the US may join us in that.

I think you can probably count on seeing that "Silver Bullet" force enter
into service...

You might be right, it may go into service, and if reports are to be
beleived - despite the cost, despite the reliability problems, despite
the obsolete architecture, the only credable justification is avoiding
an embarrising procurement fiasco, 200 odd hanger queens.....
astounding...


Cheers

John Cook

Any spelling mistakes/grammatic errors are there purely to annoy. All
opinions are mine, not TAFE's however much they beg me for them.

Email Address :-
Spam trap - please remove (trousers) to email me
Eurofighter Website :- http://www.eurofighter-typhoon.co.uk

The F/A-22 also has an inherent air-to-surface
capability." It can already lug a couple of JDAM's. So how does that even
*require* an optimized ground mapping radar to allow it to strike ground
targets with significant precision?

I'm not a bombardier, but I think the SAR radar is necessary for the INS
inputs. The INS being only updated by the GPS, and only if the GPS
isn't being jammed (which will be unlikely down the road). I think I read
where GPS only doubles the accuracy of the INS (50 feet versus 100 feet).

Without SAR, and GPS being jammed, you'll need a good pair of TACAN's,
which some enemies don't seem to provide :-)

"D. Strang" wrote in message
news:1%obc.4658$zc1.3787@okepread03...
The F/A-22 also has an inherent air-to-surface
capability." It can already lug a couple of JDAM's. So how does that
even
*require* an optimized ground mapping radar to allow it to strike ground
targets with significant precision?

I'm not a bombardier, but I think the SAR radar is necessary for the INS
inputs. The INS being only updated by the GPS, and only if the GPS
isn't being jammed (which will be unlikely down the road). I think I read
where GPS only doubles the accuracy of the INS (50 feet versus 100 feet).

Without SAR, and GPS being jammed, you'll need a good pair of TACAN's,
which some enemies don't seem to provide :-)

I have yet to hear that a SAR update is required. Doing so would require the
preloaded data for the terrain (so that the SAR would have something to
relate its picture to). From what i understand, the weapon gets its update
from the aircraft (through its own INS), then after release it uses GPS to
improve the accuracy of its own INS. If SAR was required, then I guess the
A-10 would never be certified to carry JDAM...?

Brooks

"Kevin Brooks" wrote
"D. Strang" wrote
The F/A-22 also has an inherent air-to-surface
capability." It can already lug a couple of JDAM's. So how does that
even
*require* an optimized ground mapping radar to allow it to strike ground
targets with significant precision?

I'm not a bombardier, but I think the SAR radar is necessary for the INS
inputs. The INS being only updated by the GPS, and only if the GPS
isn't being jammed (which will be unlikely down the road). I think I read
where GPS only doubles the accuracy of the INS (50 feet versus 100 feet).

Without SAR, and GPS being jammed, you'll need a good pair of TACAN's,
which some enemies don't seem to provide :-)

I have yet to hear that a SAR update is required. Doing so would require the
preloaded data for the terrain (so that the SAR would have something to
relate its picture to). From what i understand, the weapon gets its update
from the aircraft (through its own INS), then after release it uses GPS to
improve the accuracy of its own INS. If SAR was required, then I guess the
A-10 would never be certified to carry JDAM...?

An A-10 at altitude? What a waste. They were designed to be down with the
tanks...

The way I picture it, and I admit I may be completely bogus on this, but I
picture the navigator finding a reference point (coordinates), and then using
the SAR to find the point in weather, and then updating the INS from this
point. You wouldn't need SAR if the point was available by other means,
or the target could tolerate greater than 100 foot error. For example, if
a 2k/lb jobber hit 500 foot from my house, I'd still be dead, and the house
would be destroyed :-)

"D. Strang" wrote in message
news:HNpbc.4808$zc1.3884@okepread03...
"Kevin Brooks" wrote
"D. Strang" wrote
The F/A-22 also has an inherent air-to-surface
capability." It can already lug a couple of JDAM's. So how does that
even
*require* an optimized ground mapping radar to allow it to strike
ground
targets with significant precision?

I'm not a bombardier, but I think the SAR radar is necessary for the
INS
inputs. The INS being only updated by the GPS, and only if the GPS
isn't being jammed (which will be unlikely down the road). I think I
read
where GPS only doubles the accuracy of the INS (50 feet versus 100
feet).

Without SAR, and GPS being jammed, you'll need a good pair of TACAN's,
which some enemies don't seem to provide :-)

I have yet to hear that a SAR update is required. Doing so would require
the
preloaded data for the terrain (so that the SAR would have something to
relate its picture to). From what i understand, the weapon gets its
update
from the aircraft (through its own INS), then after release it uses GPS
to
improve the accuracy of its own INS. If SAR was required, then I guess
the
A-10 would never be certified to carry JDAM...?

An A-10 at altitude? What a waste. They were designed to be down with
the
tanks...

The way I picture it, and I admit I may be completely bogus on this, but I
picture the navigator finding a reference point (coordinates), and then
using
the SAR to find the point in weather, and then updating the INS from this
point. You wouldn't need SAR if the point was available by other means,
or the target could tolerate greater than 100 foot error. For example, if
a 2k/lb jobber hit 500 foot from my house, I'd still be dead, and the
house
would be destroyed :-)

I am guessing that the primary means of updating the aircraft INS is via
GPS; maybe BUFFDRVR or one of the folks who has a clue can answer that
question. Otherwise you'd have a wee bit of a problem if your target was a
coastal one and your ingress was from over the water, or if you were
dropping it over a nice, relatively flat desert plain where you could not
get much in the line of significant terrain features from which to perform
your update, etc.

Brooks

"Kevin Brooks" wrote

"D. Strang" wrote

The way I picture it, and I admit I may be completely bogus on this, but
I
picture the navigator finding a reference point (coordinates), and then
using
the SAR to find the point in weather, and then updating the INS from
this
point. You wouldn't need SAR if the point was available by other means,
or the target could tolerate greater than 100 foot error. For example,
if
a 2k/lb jobber hit 500 foot from my house, I'd still be dead, and the
house
would be destroyed :-)

I am guessing that the primary means of updating the aircraft INS is via
GPS; maybe BUFFDRVR or one of the folks who has a clue can answer that
question. Otherwise you'd have a wee bit of a problem if your target was a
coastal one and your ingress was from over the water, or if you were
dropping it over a nice, relatively flat desert plain where you could not
get much in the line of significant terrain features from which to perform
your update, etc.

On-board SAR's main purpose in fighters is autonomous targeting. As far as I
know, no fighter is planned to have GMTI functions but SAR imaging has been
a standard function for a long time. Other targeting options of course
include off-board sensors and Guys On the Ground. GPS is unlikely to be
jammed for aircraft since any ground based jammer is going to be 'way out of
the main lobe of an AJ GPS antenna. JDAM and SDB are going to get AJ
antennas as well.

There is an issue with geolocation. From what I've read in AvWeek,
geolocation errors are the dominant error term in the JSTARS to JDAM loop.
B2s (again according to AW) are the most accurate platform for RADAR imaging
and targeting, which is surprising.

In article , "Kevin Brooks"
wrote:

"D. Strang" wrote in message
news:1%obc.4658$zc1.3787@okepread03...
The F/A-22 also has an inherent air-to-surface
capability." It can already lug a couple of JDAM's. So how does that
even
*require* an optimized ground mapping radar to allow it to strike ground
targets with significant precision?

I'm not a bombardier, but I think the SAR radar is necessary for the INS
inputs. The INS being only updated by the GPS, and only if the GPS
isn't being jammed (which will be unlikely down the road). I think I read
where GPS only doubles the accuracy of the INS (50 feet versus 100 feet).

Without SAR, and GPS being jammed, you'll need a good pair of TACAN's,
which some enemies don't seem to provide :-)

I have yet to hear that a SAR update is required. Doing so would require the
preloaded data for the terrain (so that the SAR would have something to
relate its picture to). From what i understand, the weapon gets its update
from the aircraft (through its own INS), then after release it uses GPS to
improve the accuracy of its own INS. If SAR was required, then I guess the
A-10 would never be certified to carry JDAM...?

That's ridculous.

SAR updates to pre-programmed INS settings have been used since the
early 90's to improve the accuracy of GPS aided munitions.

You don't need the SAR update to launch a JDAM, but it dramatically
improves the CEP of the weapon and essentially means that you can use
a smaller weapon to take out a target.

--
Harry Andreas
Engineering raconteur

"Harry Andreas" wrote in message
...
In article , "Kevin Brooks"
wrote:

"D. Strang" wrote in message
news:1%obc.4658$zc1.3787@okepread03...
The F/A-22 also has an inherent air-to-surface
capability." It can already lug a couple of JDAM's. So how does that
even
*require* an optimized ground mapping radar to allow it to strike
ground
targets with significant precision?

I'm not a bombardier, but I think the SAR radar is necessary for the
INS
inputs. The INS being only updated by the GPS, and only if the GPS
isn't being jammed (which will be unlikely down the road). I think I
read
where GPS only doubles the accuracy of the INS (50 feet versus 100
feet).

Without SAR, and GPS being jammed, you'll need a good pair of TACAN's,
which some enemies don't seem to provide :-)

I have yet to hear that a SAR update is required. Doing so would require
the
preloaded data for the terrain (so that the SAR would have something to
relate its picture to). From what i understand, the weapon gets its
update
from the aircraft (through its own INS), then after release it uses GPS
to
improve the accuracy of its own INS. If SAR was required, then I guess
the
A-10 would never be certified to carry JDAM...?

That's ridculous.

No, what is ridiculous is your misunderstanding of my statement. As you
acknowledge later, SAR is NOT required to launch a JDAM. And correct me if I
am wrong, but you do indeed have to have a digital terrain model data set
loaded in order to use the SAR to update a location--merely looking at the
screen and saying, "Yep, that's a bridge!" doesn't cut it--the system would
have to know that the bridge is at (insert 10 digit grid for centerpoint),
either by vurtue of having access to a DTM or by inputting the accurate
coordinates? The following article indicates that the basic procedure for
JDAMS usage is as I described it--the carrying platform updates the weapon
through both its own INS and GPS systems; use of a SAR, as in the case of
the B-2 JDAM usage in Kosovo and Afghanistan, does indeed increase the
accuracy further.

http://www.aero.org/publications/cro...er2002/05.html


SAR updates to pre-programmed INS settings have been used since the
early 90's to improve the accuracy of GPS aided munitions.

Uhmmm...Harry, what GPS guided munitions were in service during the "early
90's"? JDAMS was not; perhaps the ALCM or SLCM used GPS updates in
conjunction with their stored DTM (but there you go again, that pesky
DTM...); I can't think of any others that used GPS during that timeframe.


You don't need the SAR update to launch a JDAM, but it dramatically
improves the CEP of the weapon and essentially means that you can use
a smaller weapon to take out a target.

Well, it improves it, but not sure how "dramatically"; dramatic improvement
of JDAMS appears to be dependent upon use of a secondary IR imaging system
(DAMASK) or ISAR input after the drop, as was tested in the joint F-16
dropped, and E-8 updated AMSTE (Affordable Moving Surface Target
Engagement) JDAM.

Brooks


--
Harry Andreas
Engineering raconteur

Uhmmm...Harry, what GPS guided munitions were in service during the "early
90's"?

SLAM. OT&E was courtesy of Desert Storm.