Forum: Air Power

To answer the original question, Is it worth it? I think you would only have to ask the aircrew who has to utilize the technology over a hostile environment to accomplish an assigned mission to get an accurate answer to that question... Two Cents

(As opposed to the aircrew that has to accomplish the same mission without it)

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My 3 cents!!!

Is stealth worth it, it depends. What you could have bought for the money. Are 10 F-16s better then one F-22? Depends again. And BTW I am just tossing out the numbers I don’t really know the cost difference between the two. 10 F-16s can carry more ordnance, for the mud missions. 10 JTIDS or what ever they are calling it linked F-16s would be able to take out a single Raptor with no problems; yeah some 16s would get shot down in the process. The problem is a single F-22 going supersonic is NOT stealthy. Its emitting HEAT that can be picked up by IRST systems, matter of fact those systems are so sensitive that they can pick up the warm fuel in the wings. If the F-22 turns on its radar that’s a big “Here I am beacon” yeah they can get updates from other aircraft, but you don’t need stealth to do that either and any aircraft that’s emitting radar is a sitting duck, I don’t care how much Chaff you got!! Just fire up that Air to Air anti-radar missile. I would not want to be in an AWACS in a shooting war. To be truly stealthily you need to contain ALL emissions, IR, Radar, radio, SOUND, even visual. With next gen missiles like the Aim-9X. Even a “Stealth” aircraft is venerable. For the F-22 to take out an Aim-9X equipped aircraft it would have to use BVR missiles. To do that it has to use SOMETHING with RADAR in it. If the RADAR is on its also detectable. The Russians have anti-Radar versions of the AA-9. Scenario 1 F-22 turns on its RADAR, BAM its detected and now has several AA-9s racing toward it, or similar missiles, forcing it to go defensive. F-22 cuts off its radar, the more advance missiles continue to track last position and can possibly still get a kill, but much less likely. Scenario 2 F-22 is using a “Donor” aircrafts (Target) radar it stays Radar stealthy while the DONOR aircraft receives all the AA-9s. Problem is the AA-9s have a long range, are fast, and because its tracking a POWERFUL emitter such as an AWACS it may take out the AWACS before the slammers can go active or possibly before they are even launched. Scenario 3 F-22 is “Super cruising” to give the “Slammers” more energy before launch, however by doing so its also heating itself up, I mean its great that it doesn’t have to use AB for this, however the entire airframe is heating up due to the friction of the air, and even slight temp differences are detectable. Granted if an enemy is using IRST as an offensive weapon, you better know where YOUR friends are as with IRST you can’t really ID what you’re shooting at. I am ignoring all the Close in scenarios because IMHO close in the F-22 is probably no better to slightly better then the current crop of SU-35s, Mig-33s/35s, ect. Meaning it would come down to who got off the first shot. The problem with the F-22 besides its price is how do you keep stealthy when you turn on your radar you negate ALL the stealth, The FASTER you go the MORE IR you are putting out, anything you transmit can be received and tracked. Bottom line I would take say the F-22 is the best Air to Air fighter hands down, how ever what could you have purchased combat capability wise instead of a single F-22? Perhaps a fleet of small stealth drones that can do maneuvers that would KILL a human. 8 or 9 F-16s? You pick.

Radar wise the F-22 is stealthy; I am talking NORMAL radar, not the low freq or OTH stuff, which is worth mentioning because they may be able to be configured to detect stealth from above.

IR wise-the F-22 is semi-stealthy. Just look at any video shot with an IR cam. You can see the warm fuel loads, and or engines. The current IRST systems the Russians have are even more sensitive. The new gen of A to A missiles can lock on to the heat generated at the leading edge of a wing, how do you hide this? By either flying slower, and or being smaller, both of which are easier to accomplish with a drone.

Noise wise the F-22 is NOT stealthy.

Visually the F-22 is a pretty BIG aircraft.

kamov wrote:

Are 10 F-16s better then one F-22? Depends again. And BTW I am just tossing out the numbers I don’t really know the cost difference between the two.

The latest Block 60 F-16s vs F-22 is more like 3-1 or 4-1.. nowhere near 10-1

kamov wrote:

Its emitting HEAT that can be picked up by IRST systems, matter of fact those systems are so sensitive that they can pick up the warm fuel in the wings.

If you are close enough to see the ‘warm fuel’ in a F-22 with IRST, you already have a AIM-120 or two headed your way.

kamov wrote:

If the F-22 turns on its radar that’s a big “Here I am beacon”

You have heard of LPI right?? Look it up. The F-22 has been using LPI in all of it’s war games so far and nobody saw them coming.

kamov wrote:

yeah they can get updates from other aircraft, but you don’t need stealth to do that either and any aircraft that’s emitting radar is a sitting duck, I don’t care how much Chaff you got!!

Um, have you done any research? Think of the radar-emitting F-22 as a quarterback in a football game, except that you cannot see the rest of the team. The QB is sitting at 200km on full-power detection mode and the rest of the team is at 50-75 km not emitting. When the team launches, they use targeted LPI for mid-course corrections thereby not giving their location away.

Meanwhile, the Russian fighters launch against the QB. Half way to the target, the QB stops emitting and the Russians lose track and cannot provide mid-course corrections to their missiles. The active radar in the missiles themselves are too weak to break through the combined ECM and stealth features of the F-22 to ever get a lock.

And finally, the QB team’s AIM-120s arrive and decimate the Russian fighters.

kamov wrote:

With next gen missiles like the Aim-9X. Even a “Stealth” aircraft is venerable. For the F-22 to take out an Aim-9X equipped aircraft it would have to use BVR missiles.

No kidding Wink

kamov wrote:

To do that it has to use SOMETHING with RADAR in it. If the RADAR is on its also detectable. The Russians have anti-Radar versions of the AA-9. Scenario 1 F-22 turns on its RADAR, BAM its detected and now has several AA-9s racing toward it, or similar missiles, forcing it to go defensive. F-22 cuts off its radar, the more advance missiles continue to track last position and can possibly still get a kill, but much less likely. Scenario 2 F-22 is using a “Donor” aircrafts (Target) radar it stays Radar stealthy while the DONOR aircraft receives all the AA-9s. Problem is the AA-9s have a long range, are fast, and because its tracking a POWERFUL emitter such as an AWACS it may take out the AWACS before the slammers can go active or possibly before they are even launched.

No anti-radar seeker on a Russian missile will be able to detect the F-22 LPI modes. That’s the point of LPI, Low Probability of Intercept. Also, LPI was compared to the FULL-SIZE sensor suites in a fighter. The small sensors of a missile never had a chance. Btw, AWACS are upgrading to LPI enabled AESA radars…

kamov wrote:

The problem with the F-22 besides its price is how do you keep stealthy when you turn on your radar you negate ALL the stealth,

I will say it again LPI

kamov wrote:

Radar wise the F-22 is stealthy; I am talking NORMAL radar, not the low freq or OTH stuff, which is worth mentioning because they may be able to be configured to detect stealth from above.

Lower frequency radars “might” detect a F-22, but it will not be able to track. The best you will get is that the F-22 is somewhere in “that” direction at “about” xx miles. You will never be able to provide fire control using lower frequency radars.

And lastly, IIRC pilots reported that even when they could SEE the F-22 in the distance, they could not get a lock in order to launch.

Don’t drink too much of the LPI cool-aid. I don’t care what method you use be it wider-frequency bandwidth freq hopping, freq modulation, continues wave, and or pulse compression, if its emitted its detectable and when it comes to emitting something the detector has the advantage. Let me simplify it. Go find a high school gymnasium, make sure it doesn’t have any windows, cut all the lights out so that its pitch black. Now have a friend walk in the FAR side with a small LED pen light. That’s your “Simulated” Radar beam. Notice how you can see him way across the gym, and he has no idea where you are until you get to with in a few feet of him. Radar is the exact same way. Notice how you can even see him if the beam is NOT even pointing in your direction? Granted you can reduce the side lobes, and power to greatly reduce this tendency. However if the main dish is facing your way, and it transmitting its detectable. Remember for radar to work it has to go “OUT & Back” while the receiver only has to deal with the Out portion of the beam strength. Also What you forget is that ANTI-RADAR Air TO Air missiles do NOT emit anything!!! Now for the complex version “The function of a Low Probability of Intercept (LPI) radar is to prevent its interception by an Electronic Support (ES) receiver. This objective is generally achieved through the use of a radar waveform that is mismatched to those waveforms for which an ES receiver is tuned. This allows the radar to achieve a processing gain, with respect to the ES receiver, that is equal to the time-bandwidth product of the radar waveform. This processing gain allows the LPI radar to overcome the range-squared advantage of the ES receiver in conventional situations. Consequently, a conventional ES receiver can only detect an LPI radar at very short ranges (<3 nm). To develop an ES receiver to detect LPI radar signals with the same sensitivity as conventional pulse signals. It implements a detector which employs a technique, known as "deramping," that forms an adaptive matched filter to the linear FMCW LPI radar signal in order to achieve the processing gain that is equal to the received signal's time-bandwidth product. An experimental transmitter was built to emulate the radar signal with FMCW characteristics and transmitted through a standard gain horn. The transmitted signal is then received via a receiver horn, mixed down to an intermediate frequency (IF), sampled by an AID convertor and digitally deramped using a Pentium II computer. It was demonstrated that the LPI radar signal can be extracted from the noise background by means of digital deramping.” that guy saays it beter then me. If you think the Ruskies are not all ready doing this and putting them in Mig-31s, 35s, and all the SU-variants you are delusional. To be truly stealthy you must emit NOTHING. Bottom line, it will always be easier to build a more sensitive receiver as it requires that you only have to acquire and process a fraction of the energy that’s required of the transmitter. Its a leap frog game..

A good read http://books.google.com/books?id=pd71EF ... #PPA155,M1

kamov wrote:

Let me simplify it. Go find a high school gymnasium, make sure it doesn’t have any windows, cut all the lights out so that its pitch black. Now have a friend walk in the FAR side with a small LED pen light. That’s your “Simulated” Radar beam. Notice how you can see him way across the gym, and he has no idea where you are until you get to with in a few feet of him. Radar is the exact same way. Notice how you can even see him if the beam is NOT even pointing in your direction?

Dude…. VERY BAD analogy.

Your forgetting the main advantage the F-22 and F-35 have in using LPI… wait for it… wait for it… AESA.

In a traditional radar vs ES comparison your analogy has merit. But, with AESA LPI, it goes out the window. AESA LPI radar sets have 1200+ INDIVIDUAL emitters transmitting on INDIVIDUAL freq waveforms. It is equiv to comparing a 1000 watt radar to 1200 .83 watt radars. The computing power needed to analyze 1200 signals, where it had previously only had to do one, is unfathomable. Throw in all the background radio noise and the task is even worse.

A better analogy is a LED flashlight against a starfield.... Which light is a star and which is a radar????

kamov wrote:

Now for the complex version….forms an adaptive matched filter to the linear FMCW LPI radar …. using a Pentium II computer.

To form an “Adaptive” match, you have to know what your matching in the first place.

kamov wrote:

If you think the Ruskies are not all ready doing this and putting them in Mig-31s, 35s, and all the SU-variants you are delusional.

Oh, I forgot how much the Ruskies have kept up with fighter upgrades. Wink

kamov wrote:

To be truly stealthy you must emit NOTHING.

One more reason for the F-35 and DAS / EOTS Smile

kamov wrote:

Bottom line, it will always be easier to build a more sensitive receiver as it requires that you only have to acquire and process a fraction of the energy that’s required of the transmitter. Its a leap frog game..

With AESA LPI, the Ruskies now have a 1000 fold gap to leap.

yo spud you might want to read up on the Mig-35s avionics suite. Or for that matter the older Mig-31M with the R-37 It’s pretty impressive. Granted its all PR fluff , but OTOH the F-22 you get the GD fluff. Take your pick. However like I said in the game of detection the receiver has the advantage. If they have figured out how to use a PII to detect an LPI transmitter. Just think what they can do with a NEW computer, I mean I was using a PII back in the late 90s. Also what about other detectable emissions such as heat, sound, and even visual. With AESA you are still emitting, and the over all effect is thousands of smaller lower powered transmitters. The receiver only has to track a few of them at MUCH MUCH higher energy levels to get a fix. (The transmitter must be able to receive the reflected energy at a much lower energy state) On top of that AESA radars run HOT. So the Ruskies can see your bright RED nose from way off using an IRST. AESA is a quantum leap however the simple physics of energy dissipation & propagation favors the receiver. It always will.

Kamov,
Well, I tried to find info on the Mig-35's RWR (the L-150 PASTEL) but have not been able to find much. If you have links to decent information, that would be nice.

As far as PR & Fluff goes, the Ruskies reign supreme in shoveling it out (Mig 1.42 or Su-47 anyone). Teh F-22 (with it's AESA LPI) has been around for many years and tested against the best the West has to offer (Eurocanards and F-15C with AESA). In all instances they "never saw them coming".

The Russkies have had no experience with LPI. I think this was the true mission of the Bears that encountered the F-22s in Alaska. If I were Russia I would have had them up there will all the detection and recording gear that they could pack to record all the EM during the intercept.

If the F-22s were smart (yes), they would have had their radars on single freq & low power in order to give the Ruskies as little intel as possible.

And please, do not EVER tout Russian computer technology... they just got the PII this year Smile

btw, Russia has stated that the IRST on the Mig-35 can only detect a Mig-29 class target, from the front, at the 15km mark!!! If you are 15km off the nose of a F-22, your plane is already on fire and hopefully you get a good chute.

I agree about the PR Fluff!!! The main advantage to AESA is actually its reliability, and not having to use Wave guides!! Lots of other advantages too such as scan rate ect. Non AESA radars had MTBF rates measured in the 100s of hours. AESA will be measured in 1000s or hours. Also a HUGE advantage is that you essentially have thousands of little radar transmitters if one fails you are still good. Kind of like those new LED stop lights. A few LEDS burn out, it still works. Unlike the old ones when you lose a single bulb its useless.

Russian electronics have their MTBF measured in minutes LMAO

OT / yeah but you probably don’t have to de-panel the whole nose to fix it!! That’s got to be my biggest beef with GD and the F-16!! You can de-panel the entire nose of a 15 using a quarter, in less then a minute!! On the 16, bust out the speed handle, and pray you don’t bust a bit in the process, or have a faulty “Star washer” so that the fastener drops on the ground and you have to spend 15 minutes looking for it with a crappy flashlight that you have to pound on the concrete every few seconds to keep it working.

kamov wrote:

OT / yeah but you probably don’t have to de-panel the whole nose to fix it!! That’s got to be my biggest beef with GD and the F-16!! You can de-panel the entire nose of a 15 using a quarter, in less then a minute!! On the 16, bust out the speed handle, and pray you don’t bust a bit in the process, or have a faulty “Star washer” so that the fastener drops on the ground and you have to spend 15 minutes looking for it with a crappy flashlight that you have to pound on the concrete every few seconds to keep it working.

Ahhh those were the days- speed handles and the dreaded cam-lock fastener. Worse than the ones that fell out, were the ones that busted. What a pain sometimes.

One point I'd like to make kamov is that I think too much is made of IRST systems. They simply are not very good at scanning large volumes of airspace. If they were, there would not be such a huge push for AESA systems by countries employing IRST systems on fighters.

If IRST systems suck why is the US developing them for the F-15?

kamov wrote:

If IRST systems suck why is the US developing them for the F-15?

When compared to LPI AESA, yes IRST has problems. But, as technology improves and we see better IR sensors, that could change.

kamov wrote:

If IRST systems suck why is the US developing them for the F-15?

Never said they suck, but radar is a better technology for finding something in a large volume of sky. If you notice, all these planes have IRST AND Radar...it can probably be deduced that they are made to complement each other.

Radar and IRST have their usefullness but both also has their limitations.

If IRST is so great, then why carry around a radar...

Forum: Air Power

STEALTH- is it worth it?