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

"Paul J. Adam" wrote in message
...
In message , Kevin Brooks
writes
"John Cook" wrote in message
.. .
I've tried, and so far I can't find a single reference to an F-22
dropping any Bombs (JDAM or dumb), in fact theres only one recorded
ground attack on record for the F-22 and that was due to a PIO error.

Your whining is ceaseless in this regard. The USAF says the F/A-22 is
JDAM
capable. LMCO says it is JDAM capable. Hell, even Wikipedia says it is
JDAM
capable, IIRC! It flew the JDAM-capable Block 3.1 software back in 2002.
You
don't think it is JDAM capable--seems like you are in a distinct
minority.

When was the release clearance granted? "Capable" can mean as little as
"1760 bus, and 14-inch lugs stressed for the weight". Sometimes it can
mean less than that.

Eight years ago I helped with a request from an aircraft manufacturer
who for years had been widely advertising their maritime-patrol aircraft
as "Sting Ray capable": it was only when they had a potential sale to a
Sting Ray user that they bothered to talk to the manufacturer to find
out what that claim would actually *mean* and what modifications to the
weapon carriers were needed so that the potential customer could put
their torpedoes on the aircraft.

The sale didn't go through, they never modified the aircraft, it
couldn't use Sting Ray as is, and yet it's *still* listed as Sting Ray
capable despite the fact that it could only haul the torpedoes as
jettisonable ballast: couldn't preset them, arm them or have them start
up once in the water. (Maybe they could get the parachutes to open after
release, but that's all)

So take 'capable' with a generous pinch of salt.


I'm sure the dummy JDAMs fit the bay: hopefully the wiring harnesses
reach the relevant connectors within the snatch cone and with the
correct lanyard angle, there are EMRUs or similar for the arming wires,
and the drop characteristics have been properly explored to ensure the
weapons will leave the bay cleanly across a range of airspeeds and
attitudes (a frequent problem with bay-mounted weapons in fast jets).
However, there's nothing mentioning any of this on the Web that I could
find, other than the cheerful comment that the F-22 is 'JDAM capable'.

Some flight and drop tests would help turn the notional "capability"
into operational utility... so when were they carried out?

Ask the USAF. I trust them a bit further in this regard than I do the peanut
gallery. The software that is capable of handling the JDAM has been flying
for a couple of years now; Arnold has done wind tunnel tests of the
separation characteristics, and the F/A-22 was listed as one of the
platforms to receive clearance in a fact sheet dated June 03 (
www.af.mil/factsheets/factsheet.asp?fsID=108). Even Mr. Cook has
acknowledged that dummy drop tests were conducted. Let's see--software is in
place, dummy tests have been conducted...yep, seems like it is indeed
capable of delivering the puppy. The USAF says the F/A-22 will be able to
carry JDAM's when it enters into operational front-line service with 1st
TFW--if you disagree, take it up with them.

Brooks

"Harry Andreas" wrote in message
...
In article , John Cook
wrote:

Harry

Quick question - I just read that F-22 crew now carry cell phones for
when the systems go down, so they can talk to ground control, is this
true??

LOL, I have not heard that. But then again, like I said, I'm working
other programs, not F-22.
I'l ask the F-22 crew if they/ve heard that one.

Handheld GPS on the dash?

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

SLAM. OT&E was courtesy of Desert Storm.

In article , "Tarver Engineering"
wrote:

"Harry Andreas" wrote in message
...
In article , "Tarver Engineering"
wrote:

"Felger Carbon" wrote in message
link.net...
"Harry Andreas" wrote in message
...
In article , John Cook
wrote:


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'.

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

Methinks there's some confusion there between processors, avionics
architecture, and software.
While it's true that Intel tried to shut down i960 production
causing a
chinese fire drill, there are enough assets to get by until a new
processor is
ready.

Full disclosu I'm a retired electrical engineer. I specialized in
high-end embedded microprocessors, which the "i960" in the F-22 is. I
know nothing about designing aircraft. I do know a little about the
Intel processor at the heart of the F-22:

The i960MX was designed by Intel specifically and solely for the F-22.

Nope, the i960 is a processor designed to control printers.

There were several flavors of the i960, most of which were purely
commercial and were used as printer drivers among other things.

The i960 is the follow on of the i860, from which Intel produced the i432
MPP. The i432 was such a failure that Intel was nearly bankrupt and was
forced to sell a controlling interest of 16% of Intel to IBM; it was through
this transaction that IBM was able to corner the 8088 market. The i960
found application as a printer processor in the commercial world until some
years ago. Lockmart got the bright idea of using the i960 to replicate
Intel's i432 MPP success in the Raptor.

snip of Harry making things up

Well John, I was there. Funny, I didn't see you name listed on the IPT.
Mine was.

All this i860 & 432 stuff is just smoke that has no bearing on the decision
to use the i960. Lockheed had no say, BTW, in the i960 decision. That
was an internal Hughes decision and we had a lot of selling to do with
our customer. The stuff you snipped has the real reason for the
selection of the MX over the competition. I was there.

--
Harry Andreas
Engineering raconteur

"Harry Andreas" wrote in message
...
In article , "Tarver Engineering"
wrote:

"Harry Andreas" wrote in message
...
In article , "Tarver Engineering"
wrote:

"Felger Carbon" wrote in message
link.net...
"Harry Andreas" wrote in message
...
In article , John
Cook
wrote:


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'.

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

Methinks there's some confusion there between processors,
avionics
architecture, and software.
While it's true that Intel tried to shut down i960 production
causing a
chinese fire drill, there are enough assets to get by until a
new processor is
ready.

Full disclosu I'm a retired electrical engineer. I
specialized in
high-end embedded microprocessors, which the "i960" in the F-22
is. I
know nothing about designing aircraft. I do know a little about
the
Intel processor at the heart of the F-22:

The i960MX was designed by Intel specifically and solely for the
F-22.

Nope, the i960 is a processor designed to control printers.

There were several flavors of the i960, most of which were purely
commercial and were used as printer drivers among other things.

The i960 is the follow on of the i860, from which Intel produced the
i432
MPP. The i432 was such a failure that Intel was nearly bankrupt and was
forced to sell a controlling interest of 16% of Intel to IBM; it was
through
this transaction that IBM was able to corner the 8088 market. The i960
found application as a printer processor in the commercial world until
some
years ago. Lockmart got the bright idea of using the i960 to replicate
Intel's i432 MPP success in the Raptor.

snip of Harry making things up

Well John, I was there. Funny, I didn't see you name listed on the IPT.
Mine was.

I am pleased to be missing from that list.

All this i860 & 432 stuff is just smoke that has no bearing on the
decision
to use the i960. Lockheed had no say, BTW, in the i960 decision.

I'd say that it is a demonsable error in judgement for Hughes to fail to
consider Intel's failure WRT the i432 when estimating the risk induced by
their poor decision making in selecting the i960.

That
was an internal Hughes decision and we had a lot of selling to do with
our customer. The stuff you snipped has the real reason for the
selection of the MX over the competition. I was there.

You here claiming that you somehow determined that Hughes could do what
Intel could not shows that you have not come to terms with the dimensions of
your error, Harry. To come here now and claim the problems are a result of
your personal incompetence is hardly comforting to the American tax payer.

In article , "Tarver Engineering"
wrote:


The usual process since the early 90's.

You are way behind the power curve Harry. Have a look at the fleet numbers
for reliabilty for the F/A-18E vs the F-14s. Think about how the F-22's
target number compares.

Ummm, let me check....yep, one of my radars is on the F/A-18E/F, and it
uses COTS parts. Oh, and the new AESA radar is on the F/A-18E/F, and it
uses COTS parts, too.
Digging a little deeper; yep, I worked on the F-14D's APG-71 and that
one uses Mil-spec parts.
And, of course, I worked on ATF and F-22 back in the day.
And JSF currently.

You're trying to teach me what exactly?

Been there, done that, doing it presently, with COTS and high reliability.
BTW, the current system I'm working has a reliability number higher
than the airframe life.

--
Harry Andreas
Engineering raconteur

In article , "Kevin Brooks"
wrote:

"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

It's ridiculous that anyone would think SAR is required. That has been discussed
here over and over. BTW, DTM is not required either.
All that's required is GPS, INS, and for better accuracy, SAR.


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.

SAR updated GPS aided munitions were used by the B-2's in Bosnia with
eye-opening effect. You don't think that happened overnight?


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

not IR. SAR. And the amount depends on the performance of the radar.
Numbers will not be mentioned here.


(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.

Hmmm. DAMASK at least has a future.
Can't imagine flying an E-8 close enough to a potential target to
get useful data without becoming a target yourself.
Well, maybe in the future if they port it to a UAV.

--
Harry Andreas
Engineering raconteur

In message , Kevin Brooks
writes
"Paul J. Adam" wrote in message
...
Some flight and drop tests would help turn the notional "capability"
into operational utility... so when were they carried out?

Ask the USAF.

I've checked their website and searched elsewhe best I could do was a
five-year-old plan that had JDAM test drops sometime after 2000.
Unfortunately I don't have any personal contacts there to tap.

I trust them a bit further in this regard than I do the peanut
gallery.

I've only *done* weapon system acceptance and integration, so what do I
know?

I know this for su all "capable" means is "has not been proved
impossible".

The software that is capable of handling the JDAM has been flying
for a couple of years now; Arnold has done wind tunnel tests of the
separation characteristics, and the F/A-22 was listed as one of the
platforms to receive clearance in a fact sheet dated June 03 (
www.af.mil/factsheets/factsheet.asp?fsID=108). Even Mr. Cook has
acknowledged that dummy drop tests were conducted.

When, where and how many, out of interest? There seems to be a paucity
of data, and nobody's either claimed clearance or projected a date when
it will be achieved.

Let's see--software is in
place, dummy tests have been conducted...yep, seems like it is indeed
capable of delivering the puppy.

No.

I don't tell you combat engineering, you don't tell me how to integrate
weapons onto airframes.

"Software in place" is relatively straightforward when the weapon's in
use elsewhere and the software is developmental: "dummy tests conducted"
can be as simple as "flew with a blivet" or "conducted one safe jettison
from safe, slow and level" and certainly does not imply "cleared for
operational use".

The USAF says the F/A-22 will be able to
carry JDAM's when it enters into operational front-line service with 1st
TFW--if you disagree, take it up with them.

When was the clearance signed? If it hasn't been signed, when is it
expected?

Been there, done that, got the T-shirt, still have the scars. "Will be
able to carry" has been translated as "is able to carry, but not safely
drop or jettison, inert training versions" for contract acceptance in
the past when an aircraft program was under pressure.

The USAF don't seem to be saying it very clearly or very loudly: while
there's no reason to believe it impossible, neither is this blind
acceptance that the Raptor is currently a fully-capable JDAM-dropper
reasonable.


--
When you have to kill a man, it costs nothing to be polite.
W S Churchill

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

In message , Kevin Brooks
writes
"Harry Andreas" wrote in message
...
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"?

"In service" or "in development and undergoing testing"?

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";

Depends how good your maps are. GPS/INS guidance will hit a designated
point, but how well does that relate to the actual location of the
target? SAR radar helps a lot if you know that the target is "fourth
warehouse from the road" but your mapping isn't precisely sure about
exactly where in WGS84 co-ordinates that warehouse, or the road, is (but
you know fairly closely where, and the warehouses and the road both show
on SAR)

--
When you have to kill a man, it costs nothing to be polite.
W S Churchill

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

In article , "Tarver Engineering"
wrote:


Nope, the i960 is a processor designed to control printers.

There were several flavors of the i960, most of which were purely
commercial and were used as printer drivers among other things.

The i960 is the follow on of the i860, from which Intel produced the
i432
MPP. The i432 was such a failure that Intel was nearly bankrupt and was
forced to sell a controlling interest of 16% of Intel to IBM; it was
through
this transaction that IBM was able to corner the 8088 market. The i960
found application as a printer processor in the commercial world until
some
years ago. Lockmart got the bright idea of using the i960 to replicate
Intel's i432 MPP success in the Raptor.

snip of Harry making things up

Well John, I was there. Funny, I didn't see you name listed on the IPT.
Mine was.

I am pleased to be missing from that list.

All this i860 & 432 stuff is just smoke that has no bearing on the
decision
to use the i960. Lockheed had no say, BTW, in the i960 decision.

I'd say that it is a demonsable error in judgement for Hughes to fail to
consider Intel's failure WRT the i432 when estimating the risk induced by
their poor decision making in selecting the i960.

You're talking through your hat again John. Time to give up before you
demonstrate your ignorance of the selection process and the era
the decision was made in.


That
was an internal Hughes decision and we had a lot of selling to do with
our customer. The stuff you snipped has the real reason for the
selection of the MX over the competition. I was there.

You here claiming that you somehow determined that Hughes could do what
Intel could not shows that you have not come to terms with the dimensions of
your error, Harry. To come here now and claim the problems are a result of
your personal incompetence is hardly comforting to the American tax payer.

What are you on about? We designed and delivered a heterogeneous MPP
that works as advertised. No one else has done anything remotely close.
What programmers choose to do with it is up to them.
BTW, you're giving me way too much credit, but thanks anyway. I was part
of a very large multi-discliplinary team that fulfilled the contract design
parameters.

--
Harry Andreas
Engineering raconteur