Your gut feeling - The future of sensors vs. VLO

[Avimimus]

Briefly - What is your gut feeling:

- Will more powerful radars, working on a broader frequency spectrum, with advanced software and intelligently networked with other radars be able to defeat low-observable designs?

- How much of an advantage will VLO designs retain in the face of integrated defenses? Will designs favour ever increasing levels of stealth or will active countermeasures take over?

- Will more powerful infra-red/visual search systems overcome radar stealth at medium ranges? Will infra-red spectrum reduction will become more important than radar stealth?

What is the end-game?

Remember - I'm asking about gut feelings - they can be informed guesses, but you don't have to get this completely right.
After all - it will be decades before any of us know for sure.

 

[bobbymike]

The answers to your questions is YES! But mostly who knows or at least in my limited technical capacity.

But I would add, if we are talking about decades in the future, what role will 'speed' and self defense DEW play to counter the counter measures?

 

[Bill Walker]

My gut feel is that improved radars (new frequencies, data processing, bi-static, etc) will reduce the effectiveness of VLO. Then VLO will develop to render the new radar less effective. Then radar will evolve. Rinse and repeat as needed.

The increased effectiveness of IR has already spurred development in IR masking (VLO in a different frequency band). This will some day be countered by improved IR systems. And then....

There is no end game.

Also, in the short term a lot of the "techie" answers to VLO require lots of size and power, and things like widely spaced antenna. Maybe we will see them for ground based radars, but it will take longer to package this stuff into airborne radars and especially into missile guidance radars. It may be that VLO (or whatever VLO evolves into) will have very specific roles in the future - like defeating active homing radar guided missiles in their terminal phase.

 

[F-14D]

And of course advanced processing and sensor technology could move the game in a whole new direction. Possibly by tracking the disturbance in the air caused by an aircraft's passage. That's not that far out. Stories persist that that's the technology Russia is developing (developed?) to assist in detecting and tracking the latest generation of acoustically near-silent subs.

Hey, it worked in Under Siege 2

 

[NilsD]

The Soviets did field wake detecting sensors on Victor III class subs and this would've been in the 80's.

 

[LowObservable]

There's no final answer. However, I would submit that if you want to turn the aircraft into a submarine - that is, something that is inherently hard to detect and track, and where the hunter is constantly playing catch-up - then you have to make the same compromises as you do when you hide a ship underwater. And no sane person would recommend equipping an entire navy with submarines.


On the other hand, being less detectable is never a bad thing in itself. It just depends how much invisibility you want to pay for (remembering that the lower you go, the greater the bandwidth you have to address), whether in money or other offensive and defensive capabilities. Ultimately the question is achieving a balance between passive stealth (signature reduction), EW, active defense, speed, altitude &c., within a budget.


The risk is that if you get that wrong you may commit heavily to stealth concepts that are readily negated: suppose in the early 1930s you had decided to equip all your strategic bombers with slow-turning props and mufflers to reduce noise?


We are actually in the early days of counter-stealth, because the people who needed it most (the Russians, the Chinese and their clients) were spending relatively little money on defense technology before the early 2000s.

 

[Mike Pryce]

And of course, there's always the issue of where stealthy aircraft spend 95% of their time, e.g.:


http://theaviationist.com/wp-content/uploads/2013/05/F-22-Al-Dhafra.jpg

 

[LowObservable]

That makes this a good counter-stealth weapon, then...

 

[Hanse]

If one is reduced to attempting to deal with stealth by bombing runways that would indicate stealth is very effective indeed. (And let's not forget those magical Eurocanards are tied to the same runways.)

 

[Avimimus]

Well ...if you take a very liberal definition of runway that includes straight stretches of road. I somehow doubt that an F-22 could handle being dispersed to a 500 metre stretch of asphalt...

 

[F-14D]

The Soviets did field wake detecting sensors on Victor III class subs and this would've been in the 80's.

If I remember correctly, this was for detecting surface ships ("targets" in submarine parlance), and more importantly for use by their antiship wake homing torpedoes. The new developments are reportedly non-acoustically detecting, tracking and achieving firing solutions based on disturbance in the ocean caused by the passage of a large underwater body. Apparently, these persist longer than the conventional wake at the surface.

 

[F-14D]

If one is reduced to attempting to deal with stealth by bombing runways that would indicate stealth is very effective indeed. (And let's not forget those magical Eurocanards are tied to the same runways.)

I think what Harrier means is that 95% of the time the aircraft is at a place where its stealth doesn't matter. When you can, it's far more effective to kill aircraft on the ground than in the air.

 

[F-14D]

Well ...if you take a very liberal definition of runway that includes straight stretches of road. I somehow doubt that an F-22 could handle being dispersed to a 500 metre stretch of asphalt...

Can you say , "STOVL" or "Gripen"? In the latter case, I believe it's still true that all flights from Saab's facility are flown from within a 9 m x 800 m outline painted on the runway.

I agree with you, you're not going to see dispersed, offbase operations with the F-22. Too much support required.

 

[Mat Parry]

The risk is that if you get that wrong you may commit heavily to stealth concepts that are readily negated: suppose in the early 1930s you had decided to equip all your strategic bombers with slow-turning props and mufflers to reduce noise?


We are actually in the early days of counter-stealth, because the people who needed it most (the Russians, the Chinese and their clients) were spending relatively little money on defense technology before the early 2000s.

The quiet 1930's bomber analogy is a good one IMHO, I will resist speculating on future sensors as this was not the original question. As the US is a long way ahead in stealth I would expect the US to be a long way ahead in counter stealth? But I imagine insights towards this end are extremely closely guarded...

 

[Hanse]

As the US is a long way ahead in stealth I would expect the US to be a long way ahead in counter stealth?

BINGO!

 

[AeroFranz]

I agree that improvements in detection capability will be accompanied by efforts in signature reduction, just like any other weapon system in the history of mankind (Sword vs. shield, armor vs. projectiles, etc.)


That being said, it seems to me that low observables have smaller incremental improvement opportunities than detection sensors. I realize i am focusing on radar in the following and setting aside other observables.


Take shaping, which is known to be the most important factor affecting RCS. What happens when bi-static detection becomes available? How much better can you make RAM than what has already been done in the past 70 years? Where do you go to get additional decreases in RCS?
Contrast this with signals processing and electronics in general, which have made huge leaps with the introduction of AESA and processors that keep getting faster and faster.


In a nutshell: I don't work for Lockmart or Nothrop, so I could be wrong, but it looks to me that most LO technologies have achieved maturity and are now in the flat part of their technology S-curve. OTOH, a lot of detection technologies are at their early stage, with room for improvement, and will (could?) eventually decrease or negate the benefits of signature reduction.




The only way to keep up with disruptive technologies in detection is to introduce disruptive technologies in low observables. Now, unless we find some new material to make airplanes radar absorbent (fabled unobtainium?), or start doing creative things with active stealth, i don't see how "conventional" stealth can keep up with sensors.


I'd be interested in hearing what specific LO technologies have room for growth, or conversely which sensors technologies have little left.

 

[LowObservable]

BONGO!

The US has not had to worry too much about stealth threats until recently. The Chinese and Russians, from 1995 onwards, were confronted with a plan that called for 400+ F-22s and 600+ JSFs to be in US service by now. with 200+ JSFs coming off the line each year.

So while the US doubtless has some very good fundamental counterstealth technology, it is potential adversaries who have been motivated to apply such technology in fielded systems.


AF - Good points. I believe that there has been some advance in lower signatures for practical air vehicles - but subject to the "submarine" caveat. I don't think signatures have budged much for fighter-type aircraft, and (as you say) given the dominance of shape, it won't change very much during service life.

 

[phrenzy]

My limited understanding is that the main problem with detecting VLO aircraft with long wavelength radar is a high noise / signal ratio and that as a result the VLO vs. sensor battle is, for the most part, a matter of raw processing power to make an intelligent guess at a track. If that is the case its hard to bet against faster cheaper processing power in the long run.

I would wonder though about the possibility of producing some form of active stealth where a very quick analysis of incoming active sensor radiation and transmitting a signal that woukd appear to the recieving station as a clean signal. Something like active noise cancellation.

 

[Dragon029]

How much better can you make RAM than what has already been done in the past 70 years? Where do you go to get additional decreases in RCS?

The only way to keep up with disruptive technologies in detection is to introduce disruptive technologies in low observables. Now, unless we find some new material to make airplanes radar absorbent (fabled unobtainium?), or start doing creative things with active stealth, i don't see how "conventional" stealth can keep up with sensors.

While still in it's infancy, the field of metamaterials does provide a whole new realm of stealth; to detect the presence of something covered in metamaterials, you'd be looking at trying to find the difference in transit time, of the radiation (from your TX) travelling a metre or two extra than the radiation around it. To do that, you'd be requiring perfect skies and TX signal tolerances of extreme levels.