Forum: General F-22A Raptor forum

Elite 1K Joined: May 26, 2005 - 08:39 PM Posts: 1496

snypa777 wrote:

Basically, this is the important part, increased resolution is done ELECTRONICALLY, not optically, you basically throw more pixels at it. Exposure time is critical as well. These sensors can detect differences in spectral energy.

Believe me, I know a LOT can be done with electronic processing. My point is there is only so much information you can get (due both to the physical nature of light and the atmosphere messing things up) from a given lens and aperture size. But who knows (I certainly don't!).

I know that the ESO's VLT project uses adaptive optics that reduces the effect of atmospheric interference, and some of Boeing literature briefly mentions doing the same kind of thing. Maybe that's a possibility? But I'm still not convinced, partially because the pod is -flying- while being used, I can't see how you could stabilize it sufficiently.

(edit: Boff, thanks for that info, that would be one HECK of a telephoto lens!)

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I believe, that the French Jaguar picture is true. A heli pilot told me that he spotted a Boeing 747 at 100 km away with his NVGs, although he could not indentify the airline. The camera in the Predator A UAV can 'read' a streetname sign/ car license plate 4.5 km away. Recently tests were conducted with the Predator B equipped with the Goodrich DB-110 in the Falcon Prowl program, they imaged targets at ranges over 70 nm at 40.000 ft. There is software that can calculate the location/speed of a target detected by a camera accurately enough for an interception. So build a fleet of stealthy HALE UAVs equipped with multi-spectral / hyper-spectral IR/daylight cameras working together via datalink to hunt the Raptor.

A 747....at 100km....with NVGs....and he was able to ID the airframe? Rolling Eyes

I ain't sayin' he's fibbin', just braggin' a bit. Maybe ID'd it by it's nav light pattern, maybe. Or he knew what type of traffic would be where that night. But makin' out the airframe outline from 100 clicks with just goggles? The jitter alone induced from the rotors (intensified by the mag factor) would be incredibly disorienting.

If he in fact did, he's got better optics and stabilization in his goggles than some dedicated recce platforms.

One thing that must remember is that the best lenses for long range optical of IR detection have a very very small field of view. This is why almost all IR air to air detection systems are slaved to the radar.

In tracking a target through IRST systems, range can vary without any clue to the limits of the detection. So one minute you can detect a target at 50miles (80km) and, a few minutes later your detection range due to atmospheric conditions can be reduced by 25%, 33% or, 50% and there is nothing to tell the pilot what the maximum range until he detects something is detected.

When the F-22 pilot wants to keep his IR detection to a minimum, he can supercruise at (say) Mach 1.2, 50,000+ and, nose pitched up to a maximum of 25°.... hiding any and all hot spots. The best angle to detect the F-22 is directly behind it.

Against the F-22 pilot, he already knows the detection ranges of any RF or IR detection system. He can then maneuver his aircraft to stay outside these parameters. If the F-22 pilot elects to engage the enemy, he still can attack at his time and choosing.

Adrian

What you said about IRST's is true. But that is why all Russian IRST have a laser as part of the system. That way they can get the range while staying quiet on the F-22s warning gear.
But Modern IR sensors can detect the heat from the leading edge of an aircrafts wings and fuselage. That's a big reason why I think that an IR system will be able to track a raptor that is supercruising.
One must also assume that a smart enemy would use an acoustic system ti track aircraft by sound. In the past this type of system would be impossible do to the physics of sound traveling through the air.But with modern computers I think it would be a lot easier to do today.
Because of the three different ways open to track an aircraft I believe that the idea that the raptor will be able to cruise around without being detected and track is utterly ridiculous.

avon1944 wrote:

When the F-22 pilot wants to keep his IR detection to a minimum, he can supercruise at (say) Mach 1.2, 50,000+ and, nose pitched up to a maximum of 25°.... hiding any and all hot spots. The best angle to detect the F-22 is directly behind it.

Against the F-22 pilot, he already knows the detection ranges of any RF or IR detection system. He can then maneuver his aircraft to stay outside these parameters. If the F-22 pilot elects to engage the enemy, he still can attack at his time and choosing.

Adrian

At mach an aircrafts skin heats up, I think it is ultra-violet light that is radiated from the skin rather than IR energy. Modern detectors can "see" both IR and UV light. So...flying the profile you mentioned may not work. I agree it may be more likely to detect an F-22 from behind because of that major heat source, the exhaust. You made a very good point about the F-22 pilot knowing about the parameters of an enemy system and staying out of that envelope.That is key! In the same way that he will stay out of the acquisition "cone" of an aircraft with HOBS, HCS heater combo` in WVR.

Danhutmacher wrote:

What you said about IRST's is true. But that is why all Russian IRST have a laser as part of the system. That way they can get the range while staying quiet on the F-22s warning gear.
But Modern IR sensors can detect the heat from the leading edge of an aircrafts wings and fuselage.

The problem with laser rangers is weather, as in they don`t like it! Also, this will be no defence against the F-22 because it has a laser warning receiver in the defensive aids pack. The Russian electro optical systems stand a better chance, but again, you have to first detect the F-22 to make that work. The F-22 also has active wing leading edge cooling, special attention has been put on other "hot" parts too. The F-22 will be more difficult to detect with IR systems than nearly everything else out there, but not impossible. I don`t think anyone is saying that it is impossible to detect an F-22 with IR detection, just difficult. Just some things to think about...

Quote:

What you said about IRST's is true. But that is why all Russian IRST have a laser as part of the system. That way they can get the range while staying quiet on the F-22s warning gear.
But Modern IR sensors can detect the heat from the leading edge of an aircrafts wings and fuselage.

At the moment, yes. However I believe LWR's are on the F-22 upgrade list for 2009/10??

The PIRATE also has a laser built in for range finding and is also a very very high resolution sensor to negate the need for narrow field of view optics.

However, what RAF Typhoons have had (been fitted since tranche 1 batch 2 deliveries began) is a LWR system.. the Saudi aircraft are also getting it. Germany, Italy, Spain and Austria all think wrongly its not needed...

So a "stealthy" IRST attack becomes much more difficult on an aircraft with LWR as the instant you paint the aircraft with any kind of laser; the pilot will know he is being tracked/targetted and from what direction.

The only real risk I can see of a BVR full IR engagement currently is if the aircraft in question is carrying the R-27ET (full IR 70km range version) or MICA IR; and manages to get within firing range of these weapons.

Andy..

p.s. so people know what a LWR looks like, the one of the typhoon is a number of glass detector domes positioned at key points around the aircraft:

Tranche 1 Batch 2:

Tranche 1 Batch 1, note the blank in its place:

Ok, so you're in your mighty Typhoon cruising around during the winter time of Europe. So its your standard craptastic weather. Is your magical IRST gonna track through all the weather too? Or do you just not fly when there are clouds in the sky cause you might start soaking up missiles? Just a thought....

That was uncalled for really, I was using it as an example of how laser range finding on an IRST can give away an aircraft is there.... note i did point out it is planned for the F-22 to receive LWR and also IRST in the near future.

And European weather recently hasn't been that crap tastic... it seems to be getting alot milder Wink

Also there are certain wavelengths in the NIR and MIR bands that can, with differing degrees of success penetrate/transmit through clouds, I can't remember which ones right now without getting my remote sensing notes out from University (did an entire module on satellite remote sensing technology). Not all sensing technologies work in all weathers.etc however; if there is more than just the radar at any pilots disposal it will help increase his combat effectiveness.

Andy

Elite 1K Joined: May 26, 2005 - 08:39 PM Posts: 1496

I just don't get it.

First: No, hot objects do not radiate UV. At least not until they're already radiating in the visible spectrum also (and that is a wee bit warm, no?)

Also, you say that IR sensors have an incredibly small FOV and thus are slaved to radar. How to you then propose they spot anything if they can't get a radar return first? Would that not be like bird hunting through a straw?

Guysmiley, a correction if I may, what I should have said, is that an aircraft skin REFLECTS UV energy, which is all around us "differently" from the sky background. This "hole" can be detected and imaged. There are already 2 colour or hyperspectral seekers that can do this.This also helps them to tell the difference between counter measure flares and an aircraft. Flares also move at a different speed to the aircraft, modern missiles can ignore flares, which DO radiate in IR and UV, that is the "heat" you rightly mentioned.
My error, rightly pointed out by you! Sorry for the confusion.

And....IR sensors have a wide field and a narrow field view. In fact, several FOV arrays in some types of pods as I understand it. Yes, it would be like hunting through a straw! The idea is that the IRST picks up something interesting in it`s wide field mode, then switches to narrow field mode to take a closer look. Weather permitting.

As I have said, I ain`t no expert, just stuff I have read from reputable places and a little harking back to my college days. I did some IR thermography, but that is a distant memory so go easy on me!

Here's a question I had for quite a while that maybe someone knowledgeable with the Eurofighter can answer.

I noticed the EF had it's PIRATE system visible on the upper front left side of canopy. Now, it's not there. Where is it? Is it flushed as shown in boff's posted pics? Apologize if it's already been mentioned here as I didn't have the time to read every post here.

Full PIRATE control software is part of Tranche 1 Block 5 capability (current deliveries and tranche 1 block 2B; but all block 2A/2B will be updated to block 5); they can be installed at the moment but not fully utilised (block 2b can slave it to the HMD for targetting thats about it).

Also, they are meant as being removable... they can be fitted/removed at will and are not a permanent fixture on the aircraft.

Andy

So, for example, the EF in the picks don't have the capability until it's added/bolted/screwed on? All production EFs I've ever seen don't seem to ever have it on, just the test DAs. Question

Yes, DA's are testing it... the RAF don't fit them yet as they haven't yet cleared the HMD helmet for operational service so theres no point in fitting the PIRATE to the aircraft when they don't have the helmet to use it yet Wink

.... tpyical UK government procurement schedules that is!

There aren't many EF's currently in service with all the airforces... if you think about it... there is a single production line feeding 4 assembly lines, so deliveries to individual customers is slow, although the total number in service is now over 50.

To be honest, I don't really know why it hasn't made an operational appearence. Knowing the RAF, they only have a few examples delivered at the moment, and they aren't letting 29sqn (the training unit) use them on their aircraft reserving them for front line units. Then again, I have only once seen an RAF example pilot wearing the Helmet... so that may have only just entered the testing stage.

The RAF currently have 19 airframes at last count; 8 single seater and 11 double seaters. PIRATE will more than likely make an operational appearence in the next 6 months either with 17 sqn (the evaluation squadron) who operate 5 Single seater (2 based semi-permanently in the states) and 1 2-seater. OR the first operational front line squadron (3Sqn) stand up on 31st March whose aircraft you may see wearing them on a permanent basis.

Forum: General F-22A Raptor forum

Shooting down a Raptor via IR tracking