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Iranian S-171 stealth drone in blue sky !

@AmirPatriot my friend whatever it is but still reverse engineering it is marvelous job,forget stealth it flight control system is very complex.No doubt Iranians did a job even worth praise by enemies.
 
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Full stealth very much does exist, simply because partial stealth exists. An aircraft can adopt only some RCS-reducing techniques, since there are more than just one ways to reduce RCS. Actual size, shaping, materials, stealth coating all play a factor. Each of those techniques have certain individual aspects, like for examples the DSI.
We, at least in the US, do not use the phrases 'full stealth' and 'partial stealth'. They do not exists in our design vernacular. Sorry.

You have to look at everything on an aircraft as a 'contributor' to its final averaged out RCS value. The important word is 'contributor'. The associated word is 'contributorship'.

Let us take absorber (RAM) for example. If you use absorber on a structure to reduce its contributorship, you have to at least simulate the degree of that contributorship, prior to absorber and post absorber. Then you compare the post value to other structures nearby.

Without revealing anything classified, I can tell you this: If the post value contributorship is not at least %30 reduction from prior, then the contributorships of nearby structures will render your efforts useless.

Take the F-18, for example...

The F-18 have twin canted vertical stabilators. You RAM-ed one stab but not the other. Then you measure both. If the RAM-ed stab is not at least %30 lower than the non-RAM stab, then TACTICALLY speaking, your efforts will be for nothing.

Take my previous explanation of detection of 1m2 RCS at 120-150 km range.

If your fighter, with some RCS reduction techniques applied, becomes 1m2 at 110 km distance out, then that 10 km reduction is TACTICALLY useless, even though you are below what is acceptable for 'stealth'. At the speed of modern day jets, that 10 km will be gone in a few seconds and you will become 1m2 just in time. For you to gain any TACTICALLY advantageous position, you must become 1m2 at less than 90 km distance out.

There is no 'partial stealth' or 'full stealth' here.
 
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How many times do I have to repeat myself...? I was talking about partial and full dedication to stealth. An F/A-18 has only partial measures to reduce RCS. An F-22 has FULL dedication to reducing stealth, it's entire airframe is designed around reducing RCS as a top priority. Not so for the F-18. Stealth measures are not fully implemented on that aircraft.

Inb4 someone saying "no Amir stop saying random things from random thoughts full stealth isn't possible bla bla bla bla"
 
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It seems this guy is a little kid. You clearly don't have a clue what you're talking about. You have 3 members here, one of which is actually an experienced person in this field telling you where you're going wrong but you continue blaberring with your own theories. You're just a waste of thread space.
 
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How many times do I have to repeat myself...? I was talking about partial and full dedication to stealth. An F/A-18 has only partial measures to reduce RCS. An F-22 has FULL dedication to reducing stealth, it's entire airframe is designed around reducing RCS as a top priority. Not so for the F-18. Stealth measures are not fully implemented on that aircraft.

Inb4 someone saying "no Amir stop saying random things from random thoughts full stealth isn't possible bla bla bla bla"
Despite the fact that the concept of low radar observability have been around since WW II, the actual attempt at it is recent -- by US. As such, there are no official criteria and standard as to what constitute 'stealth', never mind that the word itself is overly broad to start.

Precisely because there are no official criteria and standards, you are free to use any word and combinations thereof as you please. But usually, it is the pioneers in the fields of the sciences and assorted human endeavors that others follows in all things, even down to the labels.

I fully understand what you are trying to convey: That the degrees of RCS reduction measures warrants certain labels.

But I am telling you that from the US point of view, and to date the US is the leader in this field, we do not employ those labels. We do not call the F-16 Super Hornet, a body that does have some RCS methods in its design, as a 'partially stealthy' fighter. We simply say that the jet has reduced RCS in comparison to the legacy Hornet. The 'Silent' in F-15 Silent Eagle is a marketing word, nothing from the engineers.
 
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Guys , I didn't want to begin a scientific discussion here ... I just meant that saegheh has lower RCS than our current drones and it's harder to detect it ....

Don't make things so complicated ....
 
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I fully understand what you are trying to convey: That the degrees of RCS reduction measures warrants certain labels.
Finally...
But I am telling you that from the US point of view

Well you can hold your views, no problem... and anyway, all I was trying to convey is that some aircraft don't go all the way in reducing RCS, doesn't matter what you call it...

It seems this guy is a little kid.
Standard insult from you. You know what sort of demographic repeats the same insults endlessly, right? It would make you a hypocrite. What's next, I'm a fucking troll? Get over yourself.

You're just a waste of thread space.
Your entire post was a waste of space. I'm the one whose trying to make a reasonable technical discussion, you are throwing insults and making accusations.
 
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What is 'low radar cross section (RCS)' mean ?

Technically speaking, there is no such thing as a 'low RCS' criteria. What we really have is 'lower' or 'higher', in other words, relative in comparison to an accepted standard.

But realistically, a 'low RCS' is an RCS level that is TACTICALLY useful to one side. Or TACTICALLY threatening to the other side.

Is there a reasonably accepted level ? Yes, there is: a clean F-16.

Why not the F-117, the world's first 'stealth' aircraft ? Because the true RCS value (level) of the F-117 is not revealed. That is why a clean F-16 is used.

Most fighter class airborne radar systems uses the X band and most have similar radar antenna dimensions, so the TACTICALLY useful range for the fighter class radar is 120-150 km. We can stretch it out to 200 km but the detection statistics decreases. So 120-150 km range is where a detection is categorized as a 'target' and traceable over time.

So the acceptable criteria is 1m2 at 120-150 km range. The one meter squared energy level is where the radar computer can reasonably process. Anything weaker and the signal can often get lost in background clutter.

Here is something everyone must understand: Any body can and will become 1m2.

A clean F-16 is 1m2 at 120-150 km range.

The F-117, F22, F-35, and B-2 WILL become 1m2 at less than 50 km. If you can detect the F-22 at less than 50 km, according to your radar, you are seconds away from death. An AIM-120 is already on the way to you.

The human body WILL become 1m2 (X-band) at sports arena field length.

A B-52 or C-5 is 1m2 at further than 200 km range.

This mean there are no such things as 'full stealth' or 'partial stealth'. Everything either approaches or departs from that 1m2 criteria.
At what range an AIM-120will become 1m^2 ?
 
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Pretty much 'in your face'. Not trying to be insulting, but a missile's frontal aspect is awfully small.
Then why bother with chaff and flares if your pilots never have a chance to use them.


By the way usually you're not the only radar in the sky what about ground radars and FLIR if your airplane equipped with one
 
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Well you can hold your views, no problem... and anyway, all I was trying to convey is that some aircraft don't go all the way in reducing RCS, doesn't matter what you call it...
But it does matter.

Names and labels set the initial mental step for understanding anything, and when the discussion involves scientific issues that requires accuracy and precision, the proper names and labels and their contexts are very important. Scientists and engineers do use casual names and labels, but they do it base on the expectation that their receivers are on the same plane of understanding. On a public forum like this one where laymen abounds, those like me who have experience in the field must tread very carefully lest I misled those lay readers.

The words 'full stealth' implies an external and fixed measurable standard, which is incorrect considering the reality that the radar cross section (RCS) value is a 'fictitious' value. I do not mean that this value, such as 1 meter square at so-and-so distance, is conjured out of someone's imagination like a book of fiction.

In popular speech, the context of 'fiction' is something imaginary and temporary. But in the field of radar detection, the context of 'fiction' is that the target is real, its radar detectability is real, but that its RCS value is a VARIABLE. Not imaginary, but a factor that has numerical variations under specific environmental conditions.

So the label 'full stealth' implies that there is a fixed standard for low radar observability based upon a known RCS value, which is not true. You are free to continue using 'full stealth', but my advice is against. Saying a design has 'some or limited RCS reduction methods employed' is indeed clumsy and is a mouthful of words, but even for scientists and engineers who love to come up with acronyms and short cuts in language, there are times when we must place a higher priority on accuracy and precision.

Guys , I didn't want to begin a scientific discussion here ... I just meant that saegheh has lower RCS than our current drones and it's harder to detect it ....

Don't make things so complicated ....
You are treading into two dangerous areas: scientific and emotional.

Whenever people say 'mine is better than yours', immediately the burden is upon me to prove why mine is better in some measurable ways. Is it taller and if it is, by how much ? And when you are insinuating that taller is superior, you are touching on the emotional side. People are touchy about that.

When you starting saying Iran is capable of doing X and there is an objection to what you say, all sides have to back up their arguments. If X intrudes into the technical realm, then everyone must negotiate that technical minefield.
 
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You already understand what I want to say , but you simply hijack the topic with discussion about technical terms
 
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Then why bother with chaff and flares if your pilots never have a chance to use them.
Countermeasures are for when you know you are under attack, which lead up to the point that surprise is always the first option for any attacker. Think about it for a moment. Who would NOT want to surprise his enemy ? You want to surprise your enemy in everything, from politics to warfare. For the item in this thread, you want the unmanned drone to be as low radar observable as possible so that you can surprise your enemy with your ability to collect intelligence.

By the way usually you're not the only radar in the sky what about ground radars and FLIR if your airplane equipped with one
All radars are line-of-sight (LOS) limited and ground radars are the most limited. As for FLIR, it is an application of infrared (IR) sensor technology. Infrared sensor is passive, have less effective 'reach out' distance, and cannot provide target range information. Not to say that IR have no use, only that its utility is less than radar.
 
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OTH Radar?
Over the horizon (OTH) radar itself have limitations, notably its size and mobility. Bouncing off the atmosphere is problematic in many ways. For starter, not every frequency can be used, and the bands that are usable can be contaminated by other sources, usually comm radio and TVs, reducing detection accuracy.
 
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