Stealth: This maybe a stupid question but..

[JayAtl]

I've been reading some posts made by Gambit on this subject matter and other more knowledgeable posters- and I have this question that maybe too simplistic.

The premise is that stealth is most effective when its further away from the exterior or in the outer threshold of a radars capability where the accuracy of that radar diminishes over a longer range or ping back ( for a lack of better word) diminishes

With that assumption in mind would stealth be effective for India/ China/ Pakistan theater? as I understand it, stealth maybe most effective against say a China vs US theater where engagements will be in " blind spots" or over areas where that exterior ranges of current radars is least effective. But with the closeness or proximity of land between India/ china/ Pakistan that effectiveness of escaping a radar will be severely hampered.

Am I on the right path or I've totally misunderstood stealth capability? if so- sorry about the dumb question.

 

[MrIndianSikh]

China license produces S300 long range SAM's and Pakistan also has SAM's that are very capable both countries use good medium power radars so still is important feature when your going against a enemy who has good SAM's/radars

even in Libya the first planes to go in were the F-22 and the B-2 spirit to destroy government SAM's having stealth aircraft is a good force multiplier and not to mention the fact you can attack targets e.g launch surgical strikes in enemy territory without detection is good for any combat scenario but then again when a country has no good air defenses regular non stealth aircraft could do the trick

 

[JayAtl]

so you are saying that stealth is still stealthly when flying over lands where top tech radars are deployed?

 

[localoca]

so you are saying that stealth is still stealthly when flying over lands where top tech radars are deployed?

Yes...

 

[MrIndianSikh]

so you are saying that stealth is still stealthly when flying over lands where top tech radars are deployed?

as long as the plane does not give away its stealth it cannot be detected e.g if the after burner was used that would deeply compromise the stealth of the aircraft as the infra red signature would go up even if your flying over areas that employ capable SAM's with AESA radar a stealth jet should not be detected unless the pilot does something to reveal himself on radar

 

[Ahmad Abdullah Ravian]

The STEALTH TECHNOLOY as viewed by an Engineer !!!
1.Radar CrosGs section (RCS)
The first goal is to cut down the size of the aircraft's radar image, called its "radar cross section," or RCS. This normally involves using radical design features and some nonmetallic materials.

A conventional fighter aircraft has an Radar Cross Section (RCS) in the region of 6 square metres. The much larger B-2B bomber, using the latest stealth technology, displays an RCS of only 0.75 square metres. By comparison, a bird in flight displays an RCS of 0.01 square metres.

Stealth plane designers have to take in account that the used materials (for instance composites) may not be transparant to radar, but they are also not completely reflective. In other words, the parts behind the skin of the plane may be invisible for the eye, but they are not for radar waves, thus causing echos.
2.Echo scattering
Curving surfaces on conventional aerodynamic bodies act as scatterers, reflecting radar waves from any angle and giving the radar operator a clear signal. The right-angled surfaces at the wing and tail roots also reflect radar signals straight back to their source.

Scintillation is a measure of how rapidly the size of the return varies with the 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.

Panels on planes are angled so that radar is scattered and no signal goes back to base.

The F-117 airframe for instance has a large number of faceted surfaces, not unlike a crystal.

The facets are presumed to
reflect radar energy away from the aircraft in any other direction than that of the radar emitter.
3.Radar absorption
A second way of stopping radar reflections is by coating the plane with material that soaks up radar energy.

These typically consist of carbon, carbon fibre componsites, or magnetic ferrite-based substance.

The result is that for instance the B-2 is reported to have the same RCS as a child's tricycle!


Flight-control surface can be made from honeycombed materials which reflect incoming radar waves internally rather than back to the radar. Radar-absorbing coatings can be applied to the surface of the body which effectively drain the energy of the radar signal.
4.Low visibility
An aircraft at low to medium altitudes tends to be a black dot against the background of the sky. To avoid this, the plane a given a special medium gray color.

The gray, when combined with light scattering at low to medium altitudes ensures about as low observability as can be possible, or a reduction to 30% in visibility.
5.Low level flight
Another technique used by aircraft to avoid radar is to fly at very low levels where there is a great deal of 'ground clutter' ... radar reflections given off by buildings and other objects. Low-level aircraft can go undetected by most radar systems.

The latest ground-defence systems however are designed to discriminate between ground-clutter and hostile planes. In addition, ground-clutter is partly avoided by using 'look down' radar systems, which track aircraft from other aircraft flying above.

Clearly the Radar Technology can be used in any area of Action , even to Hide out the VIP movement in our own Country


( Do thank if u like the Post)

 

[Awesome]

Contrary to most beliefs, stealth is still quite beatable if a country had sufficient resources to do it. Pakistan and I'm sure India don't fall in that category hence Stealth tech, would trigger another arms race and eventually a radar race between us. The same was true with Missiles, BVR, CMs and so on.

Stealth and low flying objects however should make it significantly harder for even the more resourceful nations to beat that. Some of them would always get through. Stealth UAVs of the future are going to be a pain. But its still all about terrain and anticipating where the enemy would likely come from.

 

[Safriz]

time to build an optical system for aircraft detection and tracking..
may be a metwork of sky scanning CCTV cameras
*puts on his lab coat*

 

[gambit]

sorry about the dumb question.

Not 'dumb' at all.

The premise is that stealth is most effective when its further away from the exterior or in the outer threshold of a radars capability where the accuracy of that radar diminishes over a longer range or ping back ( for a lack of better word) diminishes

Radar detection is essentially a stochastical process, fancy word for statistics. So you are correct in that the further away from the transmitter, the less statistically valid are the return echoes, assuming IF any are picked up. However...What a 'stealth' aircraft does is to try to create statistical uncertainty over as wide a range as possible of what is statistical certainty for 'non-stealth' aircrafts. So at the fringes of the radar's reach, say 200km out, what would statistically make a 'non-stealth' aircraft a suspect would make a 'stealth' aircraft statistically non-existent.

Decreasing from that 200km mark, what would statistically make a 'non-stealth' aircraft a valid target that would attract the attention of the human defenders would statistically make the 'stealth' aircraft a suspect and would attract less attention from the human operator. That is the goal of 'stealth': to render the aircraft as statistically irrelevant for as long as possible until it is no longer physically possible to do so.

So to say that 'stealth' is 'most effective' is somewhat an acceptable misunderstanding. Perhaps by 'most effective' you mean statistically 'invisible'? If so, then you are correct, but as long as the 'stealth' aircraft can halve the statistical certainty of what is normally applicable to 'non-stealth' aircrafts -- AT ANY DISTANCE FROM THE RADAR -- then whatever we have done is 'most effective'.

With that assumption in mind would stealth be effective for India/ China/ Pakistan theater? as I understand it, stealth maybe most effective against say a China vs US theater where engagements will be in " blind spots" or over areas where that exterior ranges of current radars is least effective. But with the closeness or proximity of land between India/ china/ Pakistan that effectiveness of escaping a radar will be severely hampered.

Bingo...!!! Very observant...!!!

In this scenario where the geopolitical boundaries can be overreached by technological contraptions, 'stealth' aircrafts are even more important and can render an airspace unapproachable by an adversary.

What I am saying is that if desired, country A can place its radar right at the border and peek into country B. For 'non-stealth' aircrafts, the radar station itself is the greatest threat. We did that back in Desert Storm where we took out some Iraqi early warning radars and disrupted communications between the rest. The less the geopolitical boundaries available to defend, the easier it is to create a very tight radar coverage net. Less resources required, correct? So in this, 'stealth' is indeed very important because of that halving of that statistical certainty over 'non-stealth' aircrafts.

For large geopolitical boundaries, what 'stealth' units can do is move and station themselves closer to the borders, if they deem the risks acceptable, thereby shortening the distance and time required to hit valuable targets precisely because of that halving of statistical certainty.

You must keep in mind that even though 'stealth' aircrafts would avoid infringing upon any radar networks, they would not hesitate to trespass that network in order to accomplish their mission because they are confident that they are statistically uncertain over a wide range of radar coverage and distance. When they do inevitably become statistically certain because of decreasing distance, it would be too late for the defenders. That is why 'stealth' is such a threat for all militaries, large or small, and regardless of radar coverage they can field.

 

[JayAtl]

^^^ thanks gambit. You have a knack of explaining things in layman terms. really appreciate the time taken to answer my query.

 

[gambit]

Contrary to most beliefs, stealth is still quite beatable if a country had sufficient resources to do it. Pakistan and I'm sure India don't fall in that category hence Stealth tech, would trigger another arms race and eventually a radar race between us. The same was true with Missiles, BVR, CMs and so on.

Stealth and low flying objects however should make it significantly harder for even the more resourceful nations to beat that. Some of them would always get through. Stealth UAVs of the future are going to be a pain. But its still all about terrain and anticipating where the enemy would likely come from.

Mountainous battlefields are the worst for the defenders against 'stealth' because geophysical protrusions wreaks havoc on radar deployment and coverage.

The seeking signals would be scattered by the mountain tops and if there are any aircrafts, 'stealth' or otherwise, in the valleys, any echoes would be equally scattered, making detection difficult if not impossible. That was why we had the F-111 and other terrain following techniques. Yes...The defenders can station themselves at superior elevation for coverage, but then they would expose their presence for either avoidance or attack.

 

[madooxno9]

that was one good explanation

 

[gambit]

^^^ thanks gambit. You have a knack of explaining things in layman terms. really appreciate the time taken to answer my query.

Yer welcome...

Readers, back on post 9 I said that radar detection is essentially a statistical process but did not explained WHY is it based upon statistics and why MUST it be based upon statistics. Absent the understanding why, the readers could be easily misled, unintentionally or otherwise...

The above is an example of a typical 'pulsed' radar transmission. To 'pulse' something is to simply cycle its on/off status. Can a radar transmission be continuous? Yes, and that type of transmission is called 'continuous wave' (CW), obvious enough. The problem here is that in order to determine a target's progress thru 3-dimensional space against time intervals, such as one sec or one hour, a CW transmission give us no such reference.

A series of pulses does give us that time reference. A pulse is an on/off cycle therefore it as a beginning and an end or 'finite pulse length'. Each pulse that leave the radar will have its pulse length in memory. A series of pulses is called a 'pulse train', be it ten or one hundred or one million pulses in a train. The 'finite train length' will also be in memory. It is these starting and ending times for each pulse and each pulse train that we can record a target's progress thru 3D space against time.

Here is where things get complicated...

Assume we have 100 pulses in a train. If 25 echoes are produced and picked up by the receiver, can we say that we have a valid target? Yes we can but then given the fact that there are many things that stands between us and the target that could produced a number of those 25 echoes, we could be chasing a lot of ghosts. So we raise the threshold to what we believe to be acceptable for us to expend resources to investigate, say 75% of that 100 pulses train.

Here is where things get more complicated...

A sphere in radar detection is considered the simplest body and used for references. But an aircraft is not a simple body and even the dirigible or 'blimp' or 'airship', the simplest of heavier than air vehicles, is not a simple body. Any surface irregularities may send some of that 75% of pulse echoes in other directions that we may not receive, thereby reducing our certainty to below our desired threshold. If the aircraft maneuvers, we may have 80% or even 99.999% in one second but 10% in the next second. At this point it is no longer about pulse train, as in how many pulses in a train, but in percentages that we MUST receive before we can declare to ourselves that we have a valid target.

Here is where things get more and more complicated...

A longer pulse train is not necessarily beneficial. If we go back to the pulse example above, we can see there are four basic pulse characteristics:

- Freq
- Pulse Amplitude
- Pulse Width
- Pulse Repetition Interval

If we keep the same amount of pulses in each pulse train but alter any or all of the above four characteristics and remember them, we will have groups of echoes that will carry the same characteristics at different time intervals and this will help us correlate the rise and decline of echoes against each other when they are produced by a violently maneuvering target. Does not guarantee but only help for better odds.

The process can get much much more complicated but essentially it is the need to reference a moving target against time that we need to produce pulses that made radar detection a statistical process.

 

[conworldus]

China license produces S300 long range SAM's and Pakistan also has SAM's that are very capable both countries use good medium power radars so still is important feature when your going against a enemy who has good SAM's/radars

even in Libya the first planes to go in were the F-22 and the B-2 spirit to destroy government SAM's having stealth aircraft is a good force multiplier and not to mention the fact you can attack targets e.g launch surgical strikes in enemy territory without detection is good for any combat scenario but then again when a country has no good air defenses regular non stealth aircraft could do the trick

I am sorry unless I live in a different universe, the F-22 has never been deployed to destroy anything in Libya. The F-22 as far as I know can't even do precision bombing mission because it is not equip with proper avionics...