Stealth Technology Explained!

^^ thanks for the comment. That's what i like about ATS. Your work is always rewarded if it's good unlike some other forums like woildaffairsboard etc.In order to hide from all radars terrain masking or a first strike with cruise missiles is needed. Detecting a stealth aircraft witha long wave is nowhere near accurate enough for targeting and the targeting frequencies wouldn't lock on. There are plenty of ways to take out long wave radars.

Stealth is not like money in a carpet.

An aircraft can be made stealthy from some anlges. but not from all angles. Most stealth aircraft are stealthy from the front area and are optimized to be stealthy from the front and below the aircraft since that's where the threat is coming form most of the time (ground-based radar).

Stealth reflects the radar energy away from the aircraft at an angle that does not impinge on the radar that sent the radar energy, so the radar thah is transmitting sees no return that is above the noise level. The return is there, but is directed toward places where there are unlikely to be receiving antennas.
Radar tends to relfect very well from sharp edges and straight lines, especially things like canopy edges and air intake edges. hence, the "sawtooth" canopies and air intakes that have serpentine air paths to smother the radar return.

If, for instance, a stealth aircraft directed a large reflection directly downward, there is usually no antenna pointed straight up, so there is nothing there to receive it since only an overhead aircraft would be seen and no one directs radar antennas straight up on the off chance they see a stealth aircraft fly over. If they DO see it, the stealth aircraft is already probably out of range before a response can be generated.

Most jets have little to fear from behind unless the enemy is locked on and ready to respond, so the plane is essentally gone when the enemy potentially can see the stealth fighter or bomber.

I am not saying stealth aircraft direct energy vertically downward, I am saying they direct it away from likely radar receivers.

Most stealth aircraft CAN bee seen from the rear quarter, but since they are traveling at 500 - 600 mph, it is usually of no use to anyone since they are quickly masked by terrain if flying low and are FAR away by the time they are detected if high. They also have RWR receivers so, if they ARE seen, they KNOW it and can move to a low-altitude or very high-altitude profile to evade.

Originally posted by GregPascal
Stealth is not like money in a carpet.

Ok, I'm not great with anaogies! My point was that the aircraft isn't invisible, but on the radar, it appears so small that the computer overlooks it!

If you have a better way to explain what I was trying to say, Please help me out. I'm trying to help people who might be fairly new to stealth technology understand it without all the myths and misconceptions. I already have said, I welcome any one who wants to help!

How would you explaine the idea of something that is Not Invisible, but seems so small that it's nearly impossable to find against a given background!

Tim

[edit on 5-7-2006 by ghost]

Originally posted by GregPascal
Stealth is not like money in a carpet.

An aircraft can be made stealthy from some anlges. but not from all angles. Most stealth aircraft are stealthy from the front area and are optimized to be stealthy from the front and below the aircraft since that's where the threat is coming form most of the time (ground-based radar).

Stealth reflects the radar energy away from the aircraft at an angle that does not impinge on the radar that sent the radar energy, so the radar thah is transmitting sees no return that is above the noise level. The return is there, but is directed toward places where there are unlikely to be receiving antennas.
Radar tends to relfect very well from sharp edges and straight lines, especially things like canopy edges and air intake edges. hence, the "sawtooth" canopies and air intakes that have serpentine air paths to smother the radar return.

If, for instance, a stealth aircraft directed a large reflection directly downward, there is usually no antenna pointed straight up, so there is nothing there to receive it since only an overhead aircraft would be seen and no one directs radar antennas straight up on the off chance they see a stealth aircraft fly over. If they DO see it, the stealth aircraft is already probably out of range before a response can be generated.

Most jets have little to fear from behind unless the enemy is locked on and ready to respond, so the plane is essentally gone when the enemy potentially can see the stealth fighter or bomber.

I am not saying stealth aircraft direct energy vertically downward, I am saying they direct it away from likely radar receivers.

Most stealth aircraft CAN bee seen from the rear quarter, but since they are traveling at 500 - 600 mph, it is usually of no use to anyone since they are quickly masked by terrain if flying low and are FAR away by the time they are detected if high. They also have RWR receivers so, if they ARE seen, they KNOW it and can move to a low-altitude or very high-altitude profile to evade.

Actually stealthAC have good stealthfrom moat angles only some angles will give you a significant return.

You're not just dealing with reflections - like light off of a mirror - you're dealing with the properties of electromagnetics. It's much more complex.

More troublesome than surface area or edges is the very nature of an electromagnetic signal. Not only does it bounce around - but it also induces an inverse signal in any conductor it comes across. This turns every part of an airplane into a radar transmitter. The geometry of an aircraft determines the shape and strength of the return 'lobes' - or fields of emitted energy. These are then picked up by radars.

The attempt of many stealth aircraft is to force all of these lobes into a few small areas based on the geometry of the aircraft. Some very simple ways of doing this are making leading and trailing edges of an aircraft parallel with as many other surfaces as possible. Reducing the number of surfaces also has an effect on this. Blending the body also helps to reduce this effect to some degree.

This can have very serious reprocussions for stealth aircraft. They must remain filtered out by a radar for as long as possible - these return lobes jeaprodize this, as they create unique areas of strong radar returns that will alert the target to their presence prior to their engagement.

Low observable or not - no aircraft is going to survive very well in an area full of search and tracking radars as well as SAM launchers (and multiple airborne hostiles). They are intended to catch the enemy asleep at their post - unaware - not take on their targets in a battle of attrition.

Originally posted by Aim64C

The attempt of many stealth aircraft is to force all of these lobes into a few small areas based on the geometry of the aircraft. Some very simple ways of doing this are making leading and trailing edges of an aircraft parallel with as many other surfaces as possible. Reducing the number of surfaces also has an effect on this. Blending the body also helps to reduce this effect to some degree.

This can have very serious reprocussions for stealth aircraft. They must remain filtered out by a radar for as long as possible - these return lobes jeaprodize this, as they create unique areas of strong radar returns that will alert the target to their presence prior to their engagement.

It creates scintillation in the direction of the lobe. Which is a measure of how the return size differs with the angle. The greater the variation in scintillation and the narrower the lobes the more difficult it is to track.Aircraft like the F 22 have a very small number of lobes that are very narrow and scintillize a lot as well.
www.globalsecurity.org...
A lttle Scintillation can throw off a cruise misisle off course by quite a lot

low observable or not - no aircraft is going to survive very well in an area full of search and tracking radars as well as SAM launchers (and multiple airborne hostiles). They are intended to catch the enemy asleep at their post - unaware - not take on their targets in a battle of attrition.

I'm wondering as to where you found this out because Stealth aircraft were designed to take on aophisticated and dense air defense sites and AWACS. It's aboutcreating gaps in the enemy's detection envelope and sipping through those gaps and attack a target deep within his territory and come back out. Supercuise can also be a considerable advanatge when added with stealth since it reduces loiter time over enemy territory.

en.wikipedia.org...
www.f22-raptor.com...
www.f22-raptor.com...
www.f22-raptor.com...

in order to counter mobile radrs you need good Elint/Sigint where standoff platforms like the RC 135 Rivet joint can operate and collect signals analyze and send them tot he epentrating aircraft. The F/A 22 can already do this independently.once the enemy radars have been found the mission systems will calaculate the best route to avoid the enemy and get tot the target. Sure the enemy can use popup sams in the possible corridors they can go through to have a chance but tother countermeasures like ECM wil create so many corridors to make it even more difficult.To understand this read the following link.
www.afa.org...

normal sead weapons would be AGM 88 HARM (new version with GPS and ana ctive seeker),JASSM,JSOW,MALD, ANd SDB. I'm not sure if a JSF or Raptor can carry a HARM but i know the JASSM is being shrunk to reduce size to be able to fit in the weapons bay while still retaining the same range.JSOW can be carried by both, Not sos ure about MALD but the Raptor can carry several SDB which have a range of 60 nm and use active seekers to attack mobile targets.

So in REAL simple terms, imagine an aircraft in a windtunnel, and imagine the wind as the radar, radar works on returns, minimize the returns(lets say drag if its a wind tunnel) and you minimize the chance of teh craft being noticed by the radar, hence the curvature design is quite probable in teh newer craft. Anyone want me to simplify it any further?

But the exact determination of stealthy curves is still above me. If any of you guys are highly QUALIFIED on radar then please shout out the correct answer.

Ufimtsev, the guy that originally came up with the edge wave equations used for faceted stealth like the F117A, extended them into similar equation sets for concave and convex surfaces.

So now there's numeric problem solvers that can calculate appropriately curved wing surfaces that have low RCS, only as you might imagine, calculating triangular facets is a whole lot easier and faster.

So there's a big market for vector processor arrays, yay!

urmomma, you are correct in that the purpose of stealth is to limit the radar detection thresholds to allow for combat operations inside of enemy borders - however, stealth is no longer a secret and is not difficult to defeat.

And, for the record - the F/A-22 has a very low head-on RCS. The rest of it is a lighthouse, comparitively. It is really an inferior RCS demonstrator. Lockheed dropped the ball with their repackaged F-15. It is more than detectable at other angles - which is the key to defeating stealth technology.

The fact of the matter is that Stealth aircraft are not intended to go 'into the fray' of radar rays. Most stealth aircraft take advantage of a certain angle of approach that minimises their RCS relative to their target (which will be air defense systems). They are intended to 'get the jump' on such systems and neutralize them to create the necessary tears in the 'mesh' to then 'jump into the fray'.

Remember - when an aircraft is hit up by multiple radars, its chance of being detected increases exponentially. Even if one radar cannot get a solid lock on its own - two or more radars can coordinate to illuminate the target for a passive missile.

It's a game. How many pieces do you want to lose? By placing the radars strategically and using topological advantages and paradoxes (age old placing mock-ups where the real thing would be expected to be tricks), one could effectively create a network with Soviet-era equipment that would be capable of engaging and destroying a number of stealth aircraft, unsupported by air forces.

The goal would be not to completely eliminate the first strike (reserving forces for later) - but giving a sort of bloody nose that would cause America to step back and re-evaluate the situation for a moment - cause them to lose enogh aircraft that they reconsider their plans of attack - and behave more cautiously.

I'm not deluded - it's very very unlikely that any existing country with soviet-era technology would be capable of warding off a full-scale U.S. military operation for long - but they could sure exploit fatal flaws in our technology.

The only redeeming factor is that the pilots flying these aircraft have been taught the weak points of their aircraft's radar evading features.

I can assure you, though - it is very possible to destroy 25+% of an F-22 strike force along with the supporting AWACS aircraft using soviet era technology. In fact - one of the biggest weaknesses of the status of current soviet era weaponry would be what exposes the largest weakness of the Raptor. But we'll save that for another lesson in strategy.

Oh - and I'm using soviet era weaponry because that is what we face in most countries that we would be expected to conduct military operations in. Of course - if I were to take into account some form of civil war - I could guarantee complete immunity from all U.S. air forces using U.S. technology.

Originally posted by Aim64C
urmomma, you are correct in that the purpose of stealth is to limit the radar detection thresholds to allow for combat operations inside of enemy borders - however, stealth is no longer a secret and is not difficult to defeat.

Itching to disagree with you but stealth is still pursued by almost everyone.

And, for the record - the F/A-22 has a very low head-on RCS. The rest of it is a lighthouse, comparitively.

The ADM article then argues that stealth is ”one of the features that discriminates it
[the JSF] from its competitors", neglecting to mention that the principal competitor to
the JSF, the F/A-22A, is actually built for significantly higher stealth capability than
the JSF will have. While the JSF will be much stealthier than evolved third
generation fighters and opposing Sukhois, its stealth shaping has been optimised for
the upper X-band and forward hemisphere, a viable design choice for a battlefield
strike fighter, but not for an air superiority and deep strike fighter. This is a large
departure from the F/A-22A which is built to provide high stealth in all sectors, and
over a wider range of opposing radar wavelengths. The ADM article fails to explain
that export JSFs will have further reductions in stealth performance, relative to the
US baseline, itself that much inferior to the F/A-22A.

www.ausairpower.net...
it mens the Raptor has all aspect wideband stalth capability

It is really an inferior RCS demonstrator. Lockheed dropped the ball with their repackaged F-15. It is more than detectable at other angles - which is the key to defeating stealth technology.

lol which is why the Raptor was never stopped by any of the F 15's evena fter flying over their heads and using the altest radars. lol you haven't proven anything or even provided a source.

The fact of the matter is that Stealth aircraft are not intended to go 'into the fray' of radar rays. Most stealth aircraft take advantage of a certain angle of approach that minimises their RCS relative to their target (which will be air defense systems). They are intended to 'get the jump' on such systems and neutralize them to create the necessary tears in the 'mesh' to then 'jump into the fray'.

tell this to the iraqi's who nevr even shot down an F 117 in the middile of baghdad.

Remember - when an aircraft is hit up by multiple radars, its chance of being detected increases exponentially. Even if one radar cannot get a solid lock on its own - two or more radars can coordinate to illuminate the target for a passive missile.

that is if you can even ocate the target first or identify it.

It's a game. How many pieces do you want to lose? By placing the radars strategically and using topological advantages and paradoxes (age old placing mock-ups where the real thing would be expected to be tricks), one could effectively create a network with Soviet-era equipment that would be capable of engaging and destroying a number of stealth aircraft, unsupported by air forces.

it's all about losing as little pices as possible. Out of so many air raids no F117 was lost or even detected.

The goal would be not to completely eliminate the first strike (reserving forces for later) - but giving a sort of bloody nose that would cause America to step back and re-evaluate the situation for a moment - cause them to lose enogh aircraft that they reconsider their plans of attack - and behave more cautiously.

I'm not deluded - it's very very unlikely that any existing country with soviet-era technology would be capable of warding off a full-scale U.S. military operation for long - but they could sure exploit fatal flaws in our technology.

The only redeeming factor is that the pilots flying these aircraft have been taught the weak points of their aircraft's radar evading features.

I can assure you, though - it is very possible to destroy 25+% of an F-22 strike force along with the supporting AWACS aircraft using soviet era technology. In fact - one of the biggest weaknesses of the status of current soviet era weaponry would be what exposes the largest weakness of the Raptor. But we'll save that for another lesson in strategy.

wonder how you got anywhere close to 25%.next you'll tell me the YF 23 was more maeuverable......oh wait you did

Oh - and I'm using soviet era weaponry because that is what we face in most countries that we would be expected to conduct military operations in. Of course - if I were to take into account some form of civil war - I could guarantee complete immunity from all U.S. air forces using U.S. technology.

Lol soviet era tech is what the stuff is designed for. Why don't you look at what happened to SADDAM .

The F-35 Joint Strike Fighter was a first step in the stealth reformation. Planners are considering abandoning the radar blocker in the exhaust with the idea that the 5-deg. cone of vulnerability out the aircraft's tail was an acceptable risk given the altitude at which it would fly (a margin of safety provided by the use of precision weapons). Its overall radar signature, for example, is about -30 dBsm. (the radar reflection of a golf ball) in most directions compared with -40 dBsm. (a marble) for the F/A-22.

www.aviationnow.com... Favnow%2Fnews%2Fchannel_awst_story.jsp%3Fview%3Dstory%26id%3Dnews%2F04045p02.xml

Why don't you read over the globalsecurity link i gave you it disagrees with almost ewvrything you said so far and you haven't provided anything to conflict with it.

The objective of lobing is to concentrate this unavoidable radar return into specific directions so as to minimise frontal/aft/beam aspect return and maximise scintillation in the direction of the lobe. Scintillation is a measure of how rapidly the size of the return varies with angle, the greater this variation, the more difficult a target is to track. The lower the number of lobes and the narrower the lobes, the lower the probability of detecting any return.

www.globalsecurity.org...

the stealthier the aircraft design si the better it is at doing this. the F/A 22 is a very good design and don't let the shape foll you it's a highly stealthy plane.


[edit on 5-8-2006 by urmomma158]

*sigh*

You don't get it.

No air defense system has ever been adequitely designed to defeat stealth technology. Add into that fact that stealth aircraft would fly missions in support of each other - opening up gaps that allowed for safe penetration into enemy territory.

You also fail to understand how radars work. They are capable of tracking BIRDS from at least several kilometers. Simple radar filters filter out strength returns - but more modern advancements filter based on velocity (obviously a bird will not be doing 100 knots, let alone 300 or more). And the F-22 must have some radar return for the simple fact that an invisible airframe makes for visible engines and other innards ("Good news! We've developed a material that will be 100% undetectable by radar and work well as an airframe material....... however.... it won't work for a jet engine... nor a wire....") - so you have to either reflect them someplace else, or absorb them. Since you can't absorb radar waves in the thin skin of an aircraft - you have to compromise a little.

Knowledge is the most formidable adversary ever. It doesn't matter what technology you have - a knowledge of how it works is just as lethal as a counter-technology.

How does what I say get disproven by your link? It says exactly what I say. You consolidate your returns into a very narrow onvelope. The F-22 is an inferior implementation of this approach. It works - but it certainly is not the best candidate. The F-23 was far more advanced than the F-22 in this aspect.

And, yes, it was more maneuverable. Every source I've ever read says that. Yes - so does Global Security and the people who I have talked to that worked on the project.

My word should be credibility enough for the likes of you. I will admit my errors and mistakes as I become aware of them. I am fully aware of the capabilities of the F-22A and where it stands as a combat aircraft.

Want to know how I could eliminate 25+% of an F-22 raid? Rather simple, actually.

One of the greatest weaknesses of soviet-era equipment is that it's under-maintained, out of date, and half of it just doesn't work. It's most valued use would be target practice - which is exactly what you use it for.

Reserve your operational equipment - camoflaugue it from every concievable threat. Passive sensors only - no active transmissions and set up for months in advance (hopefully avoiding satelite detection). Build convincing set of mock-ups that resemble radar instalations, then place a rather rudementary antenna set to mimic the behavior of a certain classification of radar (returns aren't necessary).

If available - equip undermaintained aircraft as drones, having them fly normal patrol waypoints.

Await the first move. The initial attack will reveal the raptor. Lighting it up from a mulitude of angles and having missiles passively acquire a target based on strong radar reflections will almost ensure a kill (excluding out-maneuvering the missile - which is possible with the Raptor).

Rather simple concept I came up with a few days ago when I last posted - worked it over a bit - and there are a lot of particulars that I would work with in reality - but as a vague and rough battle-plan....

Defense is my specialty. I build them with the anticipation of just about every concievable attack.

You must also realize that passive sensors don't work against all threats. It's like chess really although that popup sam threat you described does seem feasible under some conditions. Just try to be more clear with your responses next time because some of it before seemed quite odd until you cleared it up.

[edit on 10-8-2006 by urmomma158]

nice tim you got to tell me more about this practicalyy new here so you could help me right?

Originally posted by phsyco
nice tim you got to tell me more about this practicaly new here so you could help me right?

Sure! One thing that is a common misconception, that I haven't mentioned yet is that Stealth is about a concept known as Balanced Observables! Balances Observables is the idea of looking at all of the ways that an aircraft can be detected and trying to make sure that the detection range on each is roughly the same for each. It serves no purpose to be invisible to radar at a range of 5 miles, if the enemy can hear you coming from 20 miles away.

When steath aircraft are design, they first have to come up with a target for the Maximum Detection Range (NO stealth aircraft is truely invisible). Once they figure out how close they need to get to complete the intended mission, scientist calculate the Required Signature Values for the following aspects:

-Radar Cross Section
-Heat Signature (thermal and IR)
-Acoustic
-Electronic Emission (from radar, avionics, and radio equipment)
-Seconday Atmophereic Disturbance (these are things like changes in megnetic feild strengths, sonic booms(bad news for a stealth), and even wake turblence as the plane passes overhead)

Once scientist have figured out these signature values, the engineers then take up the task of designing an aircraft that can meet the Required Signature Values (RSV). Once a design is created it has to be tested for RSV and ability to forfill the intended mission.


KEY Stealth Teminology:

Radar Cross Sections (RCS): A mesurement of how large an object appears to be on radar. RCS is base on the surface area of a sphere (a ball), so an aircraft with an RCS of 1'000 square meters will reflect the same amount of radar enegy as a sphere with a surface area of 1'00 square meters.

Signatures: Not only how large or strong a signal you get from something such as radar but what it looks like.

Maximum Detection Range: The gratest distance at which a aircraft can be detected and identifyed. This is not only affected by the aircraft design, but also the conditions outside. For example on a clear sunny day, the Maximum Detection Range of a 747 using visual detection is much greater then it would be at night or in thick fog.

Signature Values: A precise measurement of the signatures. (this is very complicated and I'm still trying to understand all the details myself)

Electronic Emissions: detectable signals from electronic equipment such as radar signals, eletromagnetic enegy put out by computers etc., Radio waves from communications equipment, etc.

I hope that helps a little!

Tim

you kidding me tim.that helped me a lot not litttle.

this is all got tim

www.fas.org...
B-2 Spirit
The B-2 Spirit is a multi-role bomber capable of delivering both conventional and nuclear munitions.

Along with the B-52 and B-1B, the B-2 provides the penetrating flexibility and effectiveness inherent in manned bombers. Its low-observable, or "stealth," characteristics give it the unique ability to penetrate an enemy's most sophisticated defenses and threaten its most valued, and heavily defended, targets. Its capability to penetrate air defenses and threaten effective retaliation provide an effective deterrent and combat force well into the 21st century.

The blending of low-observable technologies with high aerodynamic efficiency and large payload gives the B-2 important advantages over existing bombers. Its low-observability provides it greater freedom of action at high altitudes, thus increasing its range and a better field of view for the aircraft's sensors. Its unrefueled range is approximately 6,000 nautical miles (9,600 kilometers).

The B-2's low observability is derived from a combination of reduced infrared, acoustic, electromagnetic, visual and radar signatures. These signatures make it difficult for the sophisticated defensive systems to detect, track and engage the B-2. Many aspects of the low-observability process remain classified; however, the B-2's composite materials, special coatings and flying-wing design all contribute to its "stealthiness."

~~~~~~~~~~~~~~~~~~~

You have a U2U

Added link

[edit on 1-9-2006 by masqua]

What would happen to subliminal 3phase radar with access to gps?

Or better yet 3 rader sources tuned at the same radio frequency to be refracted then reflected from a gps or other source of reflection.

If you had 3 radar waves at the same friguency one would "bounce" of each other prividing with interference that can be monitered. Think of blowing two sources of smoke together would their particles not colide at least to the naked eye?

Under the above conditions, a stealth aircraft might be detectable. As I said in my Origional post, Stealth Planes are not Invisible.

Tim

The thing with radars is that they are detectable.

A stealth aircraft knows you're searching for them because they can pick up your scan LONG before they are within detection threshold - even if you are using multiple radar emitters and some advanced combined filtering electronics. They simply stay far enough away to avoid detection, send a Anti radiation missile (or tomahawk - something) in your direction, or analyze your scan pattern, and calculate the anticipated detection threshold - then goose it and get as close as they can before your scaner sweeps their path. Then you have to get your tracking systems on it - and once a tracking radar lights them up - they know two things: one - you've detected them and Two - you've got a steady beam on them (thus a solid beacon for a HARM).

Of course - there are other means of detection, as has already been mentioned. As there are more ways of tracking an aircraft - LADAR works nicely because it's more difficult to detect (they don't know you're tracking them - giving you a decisive advantage), more accurate, and you can use it to better identify a contact by litterally 'scanning' their surface.

If you really want to take down low observable aircraft - you either bring them into visual range and have an F-5E or some maneuverable little bugger - or nail them on the runway/parking ramp. It's easier that way. It's much harder to take them out when they're attacking you.

ieeexplore.ieee.org...


A paper on the radar reflectivity of jet plumes. It may be of interest to some on here.