Can stealth be beaten...??

Originally posted by Figher Master FIN
OK... But what makes a plane stealthy then... What kind of shapes does it require...??

[edit on 15-12-2005 by Figher Master FIN]

Stealth in Aircraft is a combination of factors Including but not limited to:

1) Shape: The way the aircraft is shaped effects the return of the radar back to the sending unit. The F-117's facets angle the radar away from the reciver when it gets hit. The B-2 and the F-22 used curved shapes that do the same thing but the computing power back in the 70's was such that the caluculations needed to compute them was unavalible.

2) Structure: Internal structures can be designed to also trap and relect EM radiation

3) RAM: Radar absorbing material. These materials can absorb EM radiation and thus reduce the return to the sending unit. Paint with iron ferrite is one such application.

Originally posted by FredT

Originally posted by Figher Master FIN
OK... But what makes a plane stealthy then... What kind of shapes does it require...??

[edit on 15-12-2005 by Figher Master FIN]

Stealth in Aircraft is a combination of factors Including but not limited to:

1) Shape: The way the aircraft is shaped effects the return of the radar back to the sending unit. The F-117's facets angle the radar away from the reciver when it gets hit. The B-2 and the F-22 used curved shapes that do the same thing but the computing power back in the 70's was such that the caluculations needed to compute them was unavalible.

2) Structure: Internal structures can be designed to also trap and relect EM radiation

3) RAM: Radar absorbing material. These materials can absorb EM radiation and thus reduce the return to the sending unit. Paint with iron ferrite is one such application.

You forgot the last ingredient to the formula, suppression of hot exhaust.

Originally posted by FredT

Assuming that a country had a signifigant stealth force, the US would face the same issues as any other country in repelling such an attack. However, a country would have to have signifigant assests in close to the US to acomplish this and even the B-2's require foreward based tankers when staging from the CONUS.

One of the main facets of the AESA radars is to pick up a far more likely target that faces the US, that of stealthy cruise missiles.

The italics in the above quote are mine.

This is the main weakness in stealth aircraft. A stealth aircraft's disadvantage is that it can't use it's radar or communications systems without giving away it's position. It has to rely on support aircraft or ground based radar systems to aquire it's targets. If if is a bomber or attack aircraft it needs to be refueled or launched from a base with in range of it's target. To eliminate the advantage of a stealth aircraft all you have to do is to eliminate the support structure that it needs to function.

Originally posted by JIMC5499

The italics in the above quote are mine.

This is the main weakness in stealth aircraft. A stealth aircraft's disadvantage is that it can't use it's radar or communications systems without giving away it's position. It has to rely on support aircraft or ground based radar systems to aquire it's targets. If if is a bomber or attack aircraft it needs to be refueled or launched from a base with in range of it's target. To eliminate the advantage of a stealth aircraft all you have to do is to eliminate the support structure that it needs to function.

Is this true... I didn't even know this... Thanks for the information... We all sure learn more each day...

Originally posted by JIMC5499

In the 1980's a German by the name of Mathias Rust flew a Cessna 152 from West Germany and landed in Red Square in Moscow.

Yup, he did. And he was only 19 years old when he did it. Here he comes in for landing in 1987 (photo). More than 2,000 officers in the USSR were fired because of it.

Photo: SCANPIX/ Scan-Foto/Lehtikuva Oy (Click the photo...)

It was 20 years ago today. And the BBC doesn't even mention it on their "on this day" page... It's a conspiracy! :shk:

Originally posted by JIMC5499
Stealth aircraft like the F-117 and the B-2 are not invisable to radar. What has been done is to reduce their Radar Cross Section (RCS) to allow them to get closer to the radar before they are detected. One of the ways that I know of to defeat stealth is to improve the filters on the radar.

Yeap, smart algorithms that can remember weak returns and calculate probability of real targets then display that up will reduce effectiveness alot.


For example, say a radar gets an extremely weak return off an F-22 once every 10 sweeps, and the computer logs that weak return... then 10 sweeps later (say 10 seconds later), gets another weak return... that is 6 miles from the first return... then 10 seconds later gets another return another 6 miles from the 2nd location, along a tracjectory with a high probability of being realistic. Then that plot can be shown to the operators with the relevant data.

With computing power still obeying Moore's law (transistor density etc), and stuff in the pipeline to move that on even quicker, the ability to sift through the clutter to pick out VLO aircraft will only keep improving.

Pyros comes very close to the answer talking about bistatic arrays.

What this means is that Stealth works by preventing the radar signal from bouncing back to the radar emitter and bouncing it off somewhere else.

...but what if that somewhere else was a receiver linked by a processor to the original emitter ?

That is called a neural network. basically a system where the emitters and receivers are spaced a good distance away from each other but are linked to compare emissions with received signals.

Another solution especially for cruise missile is to bounce the signals off the ionosphere so that it looks down from above. Even with stealth technology, the design is really only intended to deflect signals from the side or from ahead.

They are not stealthy when radar beams down from above. Thus USA has developed the HAARM system in Alaska.

Some may recall that the USAF were embarassed at a Farnbourgh Air show many years ago when a rapier SAM system tracked their B-2 during a flyover.

The Rapier had an infrared tracking ball. These IR tracking balls feature on the Mig-29 and are now adopted by Eurofighter.

As for plasma screens the US have developed this too. High energy lasers excite the air ahead of a supersonic aircraft turning the air into plasma.

Sy.gunson is pretty much spot on about radar reflections and returns. But it should be taken into consideration that all stealth aircraft to date have been made to absorb radar, deflect radar, but most importantly, scatter radar. This means that although a neural network may pick up some of the scattered returns, they are still extremely weak and perhaps indistunguishable from a normal echo or background noise.

Despite this, yes, stealth can be countered, just not extremely effectively YET. Within a few years this is likely to change, however.

Excuse me if I am sounding ingnorant about the ionosphere thing...but if radar comes down from the ionosphere and hits the top of the aircraft, the physics of radio waves place the return radar beam on a course away from the original station, out into space specifically. Its like when you throw a tennis ball against a wall from an angle, it bounces off at an equivalent angle, not direcly back at you. This may be a problem, but I dont know anything about it, so dont quote me on that, enlighten me instead.

Plasma stealth? As far as anyone knows, still a long way off. I know a lot about nonlinear optics and there arent that many GROUND based laser powerful enough to ionize the air. Such a laser would have to be nuclear powered. I do not doubt the concept, I doubt the practicality with current technology. We simple cant generate that type of power in a system small enough for even the largest bomber.

Something off the top of my head, dont quote me on this either because the physics of a high school freshman are probably not too accurate. Here is an idea though: Have high pressure tanks of helium and hydrogen placed in the front of the aircraft. They release streams of gas, and than a coil behind them emits electromagnetic energy. The gas ionizes and electrons leave, discharging the atoms. Radar energy is than hastily absorbed by the neutral atoms.

HAARP isn't a radar array. I assume that's the one you're talking about, since a HAARM is a missile. The one that the US was using was the OTH-B system. It's been in "warm storage" for years now. Although NOAA was looking at using it.

The U.S. Air Force's over-the-horizon-backscatter (OTH-B) air defense radar system is by several criteria the largest radar system in the world. Six one-million-watt OTH radars see far beyond the range of conventional microwave radars by bouncing their 5-28-MHz waves off the ionosphere, an ionized layer about 200 km above the earth. It was developed over 25 years at a cost of $1.5 billion to warn against Soviet bomber attacks when the planes were still thousands of miles from US air space.

In 1970, Air Force Rome Air Development Center [RADC] engineers developed and constructed components for a frequency modulation/continuous wave (FM/CW) radar capable of detecting and tracking objects at over-the-horizon ranges. The radar installation and evaluation was accomplished on 15 September, while flight tests of a Beverage array antenna were completed on 30 September. On 30 October 1970 the radar and the Beverage array were integrated and operated as a single system for the first time.

The prototype was built in Maine, with the transmitter at Moscow Air Force Station [45°08'14"N 69°48'07W] and the receiver at Columbia Air Force Station [44°47'42"N 67°48'41"W]. Experimental transmissions from the Maine site covered an arc from 16.5° to 76.5° and from 900 to 3,300 km in range. Initial testing was conducted from June 1980 to June 1981. GE Aerospace (now Lockheed Martin Ocean, Radar and Sensor Systems) in received a contract in mid-1982 for full-scale development of the program.

The West Coast Sector included an operations center at Mountain Home Air Force Base, Idaho, the transmitter at Christmas Valley, Oregon [43°16'00"N 120°21'40"W], and the receiver at Tule Lake, near Alturas, California. GE Aerospace was initially awarded a contract valued at $145 million for the first two sectors of the West Coast system, with an additional contract for the third sector for $56 million awarded in November 1987. The total value of the West Coast system contract was expected to be approximately $313 million. The system was turned over to the USAF at the end of 1990 for operational tests and evaluation.

The Department of Defense initially planned a central sector radar facing south, and an Alaska System facing north, to complement OTH-B radars on the east and west coast to detect enemy bombers and cruise missiles. With the end of the Cold War the military requirement for the central-sector radar had largely disappeared, and it was being pursued almost exclusively for the drug interdiction mission. The Congress found this system to be redundant and unnecessary for this effort.

www.globalsecurity.org...

[edit on 5/28/2007 by Zaphod58]

Blackwidow23 I am not an expert either but USA has Over the Horizon Rardar OTHR in Maine which can see 1,800nm out to sea with this ionospheric background scatter technique. It is used to track ships and planes out across the Atlantic. Australia has a similar system called Jindalee based at Longreach for the Pacific and at Kagoorie for the Indian Ocean. Russia also has OTHR.

USA also uses a form of OTHR to bounce signals down from the ionosphere to detect caves and tunnels.

Finally there is a short burst communications system which bounces signals off meteors and/or the ionosphere to communicate at great ranges.

Don't ask me about the physics.

Also re stealth the surfaces would be optimised in the horizontal plane but highly visible from above the craft.

Rather coincidentally there is an article in issue 5, 2007 of Millitary Technology that in part discusses this very thing. The article title is " Airspace Surveillance for Air Battle Management in Multinational Operations". You may be able to read the article online through the Monch publishing website but I haven't checked. But in short yes you definitely can detect stealth systems by using detection bands which they have not been optimised against (this is one problem with the F-35, it's not overly effective against long range radars). As sy.gunson and Westpoint have eluded to with OTHR systems. Even just changing the scan mode of some radars can be enough to improve the detection capabillities of legacy systems.

LEE.

The F-117 may be easily detecable by the S-300, however what about later Stealth planes? A B-2 at 50000feet? That new 'medium bomber' the USAF wants before 2020?

It's an arms race. Build more stealthy aircraft while the enemy will build more and more advanced missile systems. So no, if stealth is good enough then it will be invincible to all enemy missile systems. However there is no perfect Stealth plane nor no perfect missile system. It all depends on the plane and the radar.

[edit on 29-5-2007 by PisTonZOR]

PisTonZOR there is a name for this. It's called putting all one's eggs in one basket. The Russians know how to replicate Stealth, but aren't in any rush to do so. That suggests something.

It suggests that the Russians have a different philosophy on warfare than the US does. Stealth is expensive and the Soviet/Russian doctrine has always been quantity over quality. They would rather have a large number of rugged, durable, well performing aircraft like the SU-27, MiG-29, SU-35 than a very small number of stealth aircraft like the F-22, B-2, F-117.

Originally posted by BlackWidow23
Plasma stealth? As far as anyone knows, still a long way off. I know a lot about nonlinear optics and there arent that many GROUND based laser powerful enough to ionize the air. Such a laser would have to be nuclear powered. I do not doubt the concept, I doubt the practicality with current technology. We simple cant generate that type of power in a system small enough for even the largest bomber.

Apparently they are already using it to conceal the radar domes (I guess behind something akin to a plasma TV).

It doesn't have to cover the entire airframe to reduce its radar signature significantly.

stelth can be beaten by advance sofisticated radars, 2 radiowaves from different directions are sent out on a intersect course, if the 2 radiowaves fail to intersect then the stealth plane is blocking them and stealth is detected.
Recently this has been done not with 2 radar stations but with many to ensure if one station is taken out the others will still operate and of course for eficency.
Radiostations are placed in a circle formation with great distances betwen them, one could be in one location like north and another south of the country, any blocking of 1 single radiowave will prevent it from crossing it with the others, of course 1 plane can not block an entrire radar wave so they are built in a way so that they know the procentage of radio signal that failed to cross with the other waves and of course the location that the transmission lost it's intensity.
This tehnology is russian.


[edit on 29-5-2007 by pepsi78]

Originally posted by pepsi78
stelth can be beaten by advance sofisticated radars,

Or by hopelessly outdated barely in service radars.

One F-117 has been lost in combat, to Serbian/Yugoslav forces. On March 27, 1999, during the Kosovo War, the 3rd Battalion of the 250th Missile Brigade under the command of Colonel Zoltán Dani, equipped with the Isayev S-125 'Neva-M' (NATO designation SA-3 'Goa'), downed F-117A serial number 82-806 with a Neva-M missile. According to Wesley Clark and other NATO generals, Yugoslav air defenses found that they could detect F-117s with their "obsolete" Soviet radars operating on long wavelengths. This, combined with the loss of stealth when the jets got wet or opened their bomb bays, made them visible on radar screens. The pilot survived and was later rescued by NATO forces. However, the wreckage of the F-117 was not promptly bombed, and the Serbs are believed to have invited Russian personnel to inspect the remains, inevitably compromising the US stealth technology.[9]

www.answers.com...

2 radiowaves from different directions are sent out on a intersect course, if the 2 radiowaves fail to intersect then the stealth plane is blocking them and stealth is detected.
Recently this has been done not with 2 radar stations but with many to ensure if one station is taken out the others will still operate and of course for eficency.

Possibly one of the reasons the Russians still operates thousands of radar platforms and why their S-300 types uses so many different radars at various levels of command . We know their air defenses are very integrated but it seems many lay people have forgotten the implications for stealth aircraft.

Radiostations are placed in a circle formation with great distances betwen them, one could be in one location like north and another south of the country, any blocking of 1 single radiowave will prevent it from crossing it with the others, of course 1 plane can not block an entrire radar wave so they are built in a way so that they know the procentage of radio signal that failed to cross with the other waves and of course the location that the transmission lost it's intensity.

I don't think you will be able to get much in the way of tracking/fire control data from such systems but i suppose it may serve countries who do not have the extensive designed air defenses of the RF..

This tehnology is russian.

They were catching spies in France and Britain in these types of way back in world war two and while the specific implementation might be Russians there is nothing 'novel' about this approach.

Stellar

Originally posted by Zaphod58
It suggests that the Russians have a different philosophy on warfare than the US does. Stealth is expensive and the Soviet/Russian doctrine has always been quantity over quality.

Actually it would say that it emphasis the need for both quality AND quantity with the understanding that some 'quality' enhancements ( you don't have to paint the tank or have someone file away the sharp edges) are not worth the resource investment. Obviously countries differ in their doctrines but i think some people have gotten the impression that the Russians are not capable of producing quality while we have in fact observed them doing both when they find a given system or subsystem to be of critical importance.

They would rather have a large number of rugged, durable, well performing aircraft like the SU-27, MiG-29, SU-35 than a very small number of stealth aircraft like the F-22, B-2, F-117.

Which they have in my opinion done in the knowledge that stealth is only useful against third world nations where you can lower your casualties due to the incompetence and relative weakness of your enemies.

To sacrifice force numbers to gain 'stealth' against a country like Russia is and always has been a very bad idea. The Russians were after all operating 'stealth' aircraft during world war two and they seemed to have decided that the sacrifices in flight characteristics, range and payload were not worth the gain in possibly going undetected for a few miles more.

Since i am not sure what type of cost and performance penalties the F-22 suffers for it's LO form i will not say it's a horrible idea ( and very probably a bad idea the USAF could still well afford) but i do think that they could win a war as quickly with twice as many planes that sacrifices nothing on the hope that the enemy can't see you. If you must invest funds allocate them towards active countermeasure systems that the entire USAF can benefit by and by ensuring that the enemy planes that are chased from the skies are destroyed on the ground. In the war against Yugoslavia/Serbia over Kosovo the US were apparently able to keep the Serbs from mounting large scale air force operations but utterly unable to close the airfields or destroy significant numbers of planes on the ground or in the air. Clearly the failure was in the cruise missile and interdiction area and not due to a lack of medium and high altitude air superiority...

Against Russia this weakness just becomes more and more devastating as their Surface to air defenses are larger and deadlier by many orders of magnitude. With it's current force structure the US might gain local air superiority ( like the Germans on the East front for most of the last years) but wont in my opinion be able to employ that towards effective interdiction against ground forces.

In closing i would also rather have a large more durable force of fighters, that can land and take off& be maintained on potato fields, than have my air power restricted to one localized set of air conditioned hangers somewhere in Europe that operates planes that can only fly in good weather once every other day. That was how the F-117 worked and the B-2 still does and unless the F-22 can fly sorties at a tremendous rate in all weather not much has changed.

Stellar

In my opinion, stealth technology would not be needed if you were able to fly at incredible speeds. Who cares if they see you if they have no weapons or craft that can catch you?