By: Amiga500
- 2nd September 2014 at 11:24Permalink- Edited 1st January 1970 at 01:00
Good question, if uncomfortable for some.
Further clarity on the whole area should be provided as the PAK-DA becomes more defined.
If it is a B-2ski, then the thought-train I have proposed is erroneous. The PAK-FA is what it is because they cannot make the delicate VLO treatments serviceable in the field... so are going for kinematics to compensate for that.
By: ActionJackson
- 2nd September 2014 at 12:12Permalink- Edited 1st January 1970 at 01:00
At that time, the Soviets operated large numbers of VHF radars, so the potential capability of these against the new US aircraft would have been investigated.
The 60 foot wide, high power, low frequency, MOBATS antenna - a permanent fixture at Helendale RCS test facility in California. Helendale facility advertises the ability to test between 120MHz and 35GHz.
Those who think stealth aircraft designers somehow overlooked low frequency radar are most seriously deluding themselves.
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By: lukos
- 2nd September 2014 at 12:32Permalink- Edited 1st January 1970 at 01:00
At this point it might be worth asking yourself -
"Why did the Russians design PAK-FA to be so maneuverable when conventional logic would suggest they focus more on VLO instead?"
Two stealth aircraft walk into a bar.....
If you have 2 stealth aircraft against one another, obviously stealth works both ways. If you have a significant number up against each other then inevitably it will probably end WVR even if there are a few BVR shots. Who said BVR didn't require manoeuvrability anyway?
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By: lukos
- 2nd September 2014 at 12:41Permalink- Edited 1st January 1970 at 01:00
The 60 foot wide, high power, low frequency, MOBATS antenna - a permanent fixture at Helendale RCS test facility in California. Helendale facility advertises the ability to test between 120MHz and 35GHz.
Those who think stealth aircraft designers somehow overlooked low frequency radar are most seriously deluding themselves.
Didn't work for the F-117. It's not that they didn't test against VHF/UHF, it's just that they didn't do so well in that regime, although still far better than regular aircraft. Obviously stealth is only effective over a certain part of the EM spectrum, otherwise you wouldn't be able to see it even with your eyes.
There's also a lot more to it than just how much you bounce back. Ground or naval arrays can be multistatic and have supercomputers on the back end. E.g. Type 997 Artisan 3D can allegedly track 800-900 targets the size of a small bird doing Mach 3 at 200km range. And target a sea skimming object of that nature at 25km.
By: Mercurius
- 2nd September 2014 at 15:47Permalink- Edited 1st January 1970 at 01:00
Obviously radar makers and ECM people will do their best but since the introduction of AESA, the advantage is definitely with the radar people. If effective jamming was possible and detection easy, stealth would be redundant for air superiority purposes because every fight would end up WVR.
The future shape of air-to-air combat in a world where both sides are stealthy is a fascinating subject, but one that I have explored professionally to only a limited degree. As you might imagine, those directly involved in next-generation weapons and tactics can be remarkably laconic when dealing with an outsider. But the general idea (at least in some quarters) will still be to engage the enemy at BVR, and at least one of next generation of BVRAAM missiles will be designed with such combat in mind.
The strength won't be as easily detected as you think, because the power can be split over a pattern across the frequency range, so whilst it adds up to a lot, the individual intensity at any frequency is low and easily mistaken for noise unless you continually add everything together.
At any moment in time, all the elements in an AESA array are dedicated to a single beam-forming task, and operate at the same frequency. The result is a beam of RF energy that may have better characteristics than those from a traditional antenna, but it is still a single beam of relatively high power. The frequency of that beam may be changing from pulse to pulse, but each of these individual pulses in created by an array of elements all emitting the same frequency but with the phase delays needed to create the required beam shape and direction.
The coding isn't constant, it's time varying too and would again require prediction and more advanced ones even implement changes when an attempt at jamming is made or an enemy is detected.
As I have already explained, the pulse that the jammer manipulates and retransmits is the pulse that was sent by the radar. So whatever electronic coding or fingerprinting the original pulse contains will also be present in the version transmitted by the jammer. The radar is waiting to receive an incoming pulse whose characteristics match those of the transmitted pulse, and the jammer is happy to oblige in order to seduce the enemy radar into accepting the false signal.
This is done on a pulse-to-pulse basis, so if the next pulse sent by the hostile radar has a different fingerprint, that will be present when that next pulse is retransmitted.
Show me a fighter with a supercomputer on board and I will think nanoseconds. The problem is that at 1GHz, a single clock cycle = 1 nanosecond. One line of code, depending on what language it's in, can take anything from several clock cycles at assembly code level to dozens of clock cycles at higher language levels. That's just one line of code in what must be a very complicated program... unless you get the whole pulse, or pre-empt it, the jamming is likely ineffective.
I am not familiar with how such fast set-on speeds are achieved in practice, but nanoseconds seem to be the unit of time necessary. A recent article on DRFM in the Journal of Electronic Defense talked of a radar pulse being detected and the jamming activated in a total time of 100 nanoseconds in order to cover 90% of the pulse duration. The 10% period for which the pulse was not jammed would have a minimal effect on the effectiveness of the jamming, the author stated.
Point is do you need to permanently jam the radar or simply disrupt the kill chain?
Exactly - the Red Teams I mentioned earlier were specifically tasked with trying to devise an anti-stealth kill chain. A broken kill chain means no reliable prospect of a kill.
Laymen love to cite the downing of the F-117 as 'evidence' than low-observable technology no longer works, ignoring the fact that the aircraft was not radar-invisible, and such a quality has never been claimed for it. They ignore the fact that the F-117 completed more than 2,100 combat sorties with the loss of only a single aircraft. All that the Serbian kill demonstrated is what we have always known - get close enough to a radar-guided SAM site and you will be engageable.
By: Levsha
- 2nd September 2014 at 16:14Permalink- Edited 1st January 1970 at 01:00
Good question, if uncomfortable for some. The answer in some less thoughtful peoples minds will be US smart, Russians dumb.
Well I wouldn't say dumb exactly (your choice of words) but yes, the US certainly has a better grasp of the practical realities of aerial warfare than just about any other country.
Why is the F22 manoeuvrable?
Why not? It's got strike fighters to escort.
Why was it the original intention of the US that the F22 would be built in much larger numbers?
There was a cold war that threatened to become hot?
Why is the F35 manufacturing base spread out across so many US States?
Number of States?
Have you seen how many countries and continents the development and production of the Boeing 787 has been spread out among?
By: TR1
- 2nd September 2014 at 18:15Permalink- Edited 1st January 1970 at 01:00
The 60 foot wide, high power, low frequency, MOBATS antenna - a permanent fixture at Helendale RCS test facility in California. Helendale facility advertises the ability to test between 120MHz and 35GHz.
Those who think stealth aircraft designers somehow overlooked low frequency radar are most seriously deluding themselves.
You can test all you want, but expecting magical performance against modern VHF sets similarly to the (claimed) performance vs more common engagement radars is deluded in itself.
By: Phaid
- 2nd September 2014 at 18:47Permalink- Edited 1st January 1970 at 01:00
You can test all you want, but expecting magical performance against modern VHF sets similarly to the (claimed) performance vs more common engagement radars is deluded in itself.
Nobody is expecting magical performance. However, the assumption here seems to be that F-22 and F-35 pilots will blithely fly in a straight line toward their target, thinking they are invisible to VHF radars because they are deluded by visions of American superiority. When in fact they know very well how their aircraft performs against such systems, and, since they can see the radar long before the radar can see them, they can take appropriate action to avoid detection.
By: Levsha
- 2nd September 2014 at 19:11Permalink- Edited 1st January 1970 at 01:00
....
There seems like something flawed in those statistics given in the first thumbnail - what 5 campaigns are referred to?
In the Vietnam war those aircraft that were actually armed with BVR missiles (and let's not forget, most combat aircraft in that war were not armed with BVR missiles) had decent success with them.
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By: lukos
- 2nd September 2014 at 19:16Permalink- Edited 1st January 1970 at 01:00
The future shape of air-to-air combat in a world where both sides are stealthy is a fascinating subject, but one that I have explored professionally to only a limited degree. As you might imagine, those directly involved in next-generation weapons and tactics can be remarkably laconic when dealing with an outsider. But the general idea (at least in some quarters) will still be to engage the enemy at BVR, and at least one of next generation of BVRAAM missiles will be designed with such combat in mind.
Theoretically the current ones can if you pick the target up on IRST but at those kinds of ranges BVR separation is unlikely to be maintainable and a merge is likely.
At any moment in time, all the elements in an AESA array are dedicated to a single beam-forming task, and operate at the same frequency. The result is a beam of RF energy that may have better characteristics than those from a traditional antenna, but it is still a single beam of relatively high power. The frequency of that beam may be changing from pulse to pulse, but each of these individual pulses in created by an array of elements all emitting the same frequency but with the phase delays needed to create the required beam shape and direction.
This is not the case. The main advantage of AESA over PESA is the ability of separate T/R modules to operate on different frequencies and combine frequencies in a single beam. Each T/R module itself usually doesn't change in the middle of a pulse but theoretically there isn't anything preventing such an occurrence and there are developments at large.
As I have already explained, the pulse that the jammer manipulates and retransmits is the pulse that was sent by the radar. So whatever electronic coding or fingerprinting the original pulse contains will also be present in the version transmitted by the jammer. The radar is waiting to receive an incoming pulse whose characteristics match those of the transmitted pulse, and the jammer is happy to oblige in order to seduce the enemy radar into accepting the false signal.
This is done on a pulse-to-pulse basis, so if the next pulse sent by the hostile radar has a different fingerprint, that will be present when that next pulse is retransmitted.
But you're only duplicating it after the fact and there's nothing to say the pulse will continue as it started.
I am not familiar with how such fast set-on speeds are achieved in practice, but nanoseconds seem to be the unit of time necessary. A recent article on DRFM in the Journal of Electronic Defense talked of a radar pulse being detected and the jamming activated in a total time of 100 nanoseconds in order to cover 90% of the pulse duration. The 10% period for which the pulse was not jammed would have a minimal effect on the effectiveness of the jamming, the author stated.
Dubious. Operating a 4GHz, you'd be hard pushed to perform a program of any complexity in 400 clock cycles. If it's against a simple non-AESA radar, then that's a different matter. What radar was it against?
Exactly - the Red Teams I mentioned earlier were specifically tasked with trying to devise an anti-stealth kill chain. A broken kill chain means no reliable prospect of a kill.
Laymen love to cite the downing of the F-117 as 'evidence' than low-observable technology no longer works, ignoring the fact that the aircraft was not radar-invisible, and such a quality has never been claimed for it. They ignore the fact that the F-117 completed more than 2,100 combat sorties with the loss of only a single aircraft. All that the Serbian kill demonstrated is what we have always known - get close enough to a radar-guided SAM site and you will be engageable.
Another one was also damaged. What it could also be seen to demonstrate is that RF is part of a wider EM spectrum and RAM clearly doesn't work against the whole spectrum, hence it's unlikely to work equally against the whole RF band either. At extremely high frequencies it will also fall down. MWR and IR Lidar could be a problem for it.
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By: obligatory
- 2nd September 2014 at 19:17Permalink- Edited 1st January 1970 at 01:00
It is noteworthy that all A2A engagements are around 5 nm, give or take,
and the give or take is given by if the target is moving away or towards the missile
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By: lukos
- 2nd September 2014 at 19:21Permalink- Edited 1st January 1970 at 01:00
It is noteworthy that all A2A engagements are around 5 nm, give or take,
and the give or take is given by if the target is moving away or towards the missile
How much of your study focused on the AMRAAM era? Lumping SARH in with ARH is pointless.
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By: obligatory
- 2nd September 2014 at 19:23Permalink- Edited 1st January 1970 at 01:00
difference between SARH & ARH is irrelevant in terms of range,
except autonomous missile have an advantage at close range when the shooter might have problem keeping the nose pointed at target
but would be interesting to compare survivability of the shooter of respective missile
By: Levsha
- 2nd September 2014 at 19:30Permalink- Edited 1st January 1970 at 01:00
It is noteworthy that all A2A engagements are around 5 nm, give or take,
and the give or take is given by if the target is moving away or towards the missile
US pilots were restricted to attacking enemy aircraft that were in visual range in order to make a positive ID. What that has to do with the real performance of AIM-7 is not clear. Also, BVR missiles of the sixties were, I believe, primarily designed to shoot down bombers - not MiGs.
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By: obligatory
- 2nd September 2014 at 19:42Permalink- Edited 1st January 1970 at 01:00
1] the trend is increasing demands of positive ID,
2] the chart indicates the real performance vs piloted (and therefore) non-cooperative targets
By: halloweene
- 2nd September 2014 at 19:50Permalink- Edited 1st January 1970 at 01:00
US pilots were restricted to attacking enemy aircraft that were in visual range in order to make a positive ID. What that has to do with the real performance of AIM-7 is not clear. Also, BVR missiles of the sixties were, I believe, primarily designed to shoot down bombers - not MiGs.
Wondering why pilots preferred (ahead of engineers) a new TV channel to a new IR on Rafale's OSF?
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By: Amiga500 - 2nd September 2014 at 11:24 Permalink - Edited 1st January 1970 at 01:00
Further clarity on the whole area should be provided as the PAK-DA becomes more defined.
If it is a B-2ski, then the thought-train I have proposed is erroneous. The PAK-FA is what it is because they cannot make the delicate VLO treatments serviceable in the field... so are going for kinematics to compensate for that.
Posts: 276
By: ActionJackson - 2nd September 2014 at 12:12 Permalink - Edited 1st January 1970 at 01:00
The 60 foot wide, high power, low frequency, MOBATS antenna - a permanent fixture at Helendale RCS test facility in California. Helendale facility advertises the ability to test between 120MHz and 35GHz.
Those who think stealth aircraft designers somehow overlooked low frequency radar are most seriously deluding themselves.
Posts: 1,760
By: lukos - 2nd September 2014 at 12:32 Permalink - Edited 1st January 1970 at 01:00
Two stealth aircraft walk into a bar.....
If you have 2 stealth aircraft against one another, obviously stealth works both ways. If you have a significant number up against each other then inevitably it will probably end WVR even if there are a few BVR shots. Who said BVR didn't require manoeuvrability anyway?
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By: lukos - 2nd September 2014 at 12:41 Permalink - Edited 1st January 1970 at 01:00
Didn't work for the F-117. It's not that they didn't test against VHF/UHF, it's just that they didn't do so well in that regime, although still far better than regular aircraft. Obviously stealth is only effective over a certain part of the EM spectrum, otherwise you wouldn't be able to see it even with your eyes.
There's also a lot more to it than just how much you bounce back. Ground or naval arrays can be multistatic and have supercomputers on the back end. E.g. Type 997 Artisan 3D can allegedly track 800-900 targets the size of a small bird doing Mach 3 at 200km range. And target a sea skimming object of that nature at 25km.
Posts: 1,348
By: Mercurius - 2nd September 2014 at 15:47 Permalink - Edited 1st January 1970 at 01:00
The future shape of air-to-air combat in a world where both sides are stealthy is a fascinating subject, but one that I have explored professionally to only a limited degree. As you might imagine, those directly involved in next-generation weapons and tactics can be remarkably laconic when dealing with an outsider. But the general idea (at least in some quarters) will still be to engage the enemy at BVR, and at least one of next generation of BVRAAM missiles will be designed with such combat in mind.
At any moment in time, all the elements in an AESA array are dedicated to a single beam-forming task, and operate at the same frequency. The result is a beam of RF energy that may have better characteristics than those from a traditional antenna, but it is still a single beam of relatively high power. The frequency of that beam may be changing from pulse to pulse, but each of these individual pulses in created by an array of elements all emitting the same frequency but with the phase delays needed to create the required beam shape and direction.
As I have already explained, the pulse that the jammer manipulates and retransmits is the pulse that was sent by the radar. So whatever electronic coding or fingerprinting the original pulse contains will also be present in the version transmitted by the jammer. The radar is waiting to receive an incoming pulse whose characteristics match those of the transmitted pulse, and the jammer is happy to oblige in order to seduce the enemy radar into accepting the false signal.
This is done on a pulse-to-pulse basis, so if the next pulse sent by the hostile radar has a different fingerprint, that will be present when that next pulse is retransmitted.
I am not familiar with how such fast set-on speeds are achieved in practice, but nanoseconds seem to be the unit of time necessary. A recent article on DRFM in the Journal of Electronic Defense talked of a radar pulse being detected and the jamming activated in a total time of 100 nanoseconds in order to cover 90% of the pulse duration. The 10% period for which the pulse was not jammed would have a minimal effect on the effectiveness of the jamming, the author stated.
Exactly - the Red Teams I mentioned earlier were specifically tasked with trying to devise an anti-stealth kill chain. A broken kill chain means no reliable prospect of a kill.
Laymen love to cite the downing of the F-117 as 'evidence' than low-observable technology no longer works, ignoring the fact that the aircraft was not radar-invisible, and such a quality has never been claimed for it. They ignore the fact that the F-117 completed more than 2,100 combat sorties with the loss of only a single aircraft. All that the Serbian kill demonstrated is what we have always known - get close enough to a radar-guided SAM site and you will be engageable.
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By: Levsha - 2nd September 2014 at 16:14 Permalink - Edited 1st January 1970 at 01:00
Well I wouldn't say dumb exactly (your choice of words) but yes, the US certainly has a better grasp of the practical realities of aerial warfare than just about any other country.
Why not? It's got strike fighters to escort.
There was a cold war that threatened to become hot?
Number of States?
Have you seen how many countries and continents the development and production of the Boeing 787 has been spread out among?
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By: TR1 - 2nd September 2014 at 18:15 Permalink - Edited 1st January 1970 at 01:00
You can test all you want, but expecting magical performance against modern VHF sets similarly to the (claimed) performance vs more common engagement radars is deluded in itself.
Posts: 2,163
By: Amiga500 - 2nd September 2014 at 18:47 Permalink - Edited 1st January 1970 at 01:00
You are putting words into my mouth.
I clearly indicated an emphasis of one over the other, not a rejection of one due to the other.
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By: Phaid - 2nd September 2014 at 18:47 Permalink - Edited 1st January 1970 at 01:00
Nobody is expecting magical performance. However, the assumption here seems to be that F-22 and F-35 pilots will blithely fly in a straight line toward their target, thinking they are invisible to VHF radars because they are deluded by visions of American superiority. When in fact they know very well how their aircraft performs against such systems, and, since they can see the radar long before the radar can see them, they can take appropriate action to avoid detection.
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By: Amiga500 - 2nd September 2014 at 18:47 Permalink - Edited 1st January 1970 at 01:00
There is a difference between overlooking it and being able to do something about it.
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By: Levsha - 2nd September 2014 at 18:54 Permalink - Edited 1st January 1970 at 01:00
Well if "stealth aircraft designers" have been working on the problem for many years maybe they have indeed "being able to do something about it" ?
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By: obligatory - 2nd September 2014 at 19:00 Permalink - Edited 1st January 1970 at 01:00
....
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By: Levsha - 2nd September 2014 at 19:11 Permalink - Edited 1st January 1970 at 01:00
There seems like something flawed in those statistics given in the first thumbnail - what 5 campaigns are referred to?
In the Vietnam war those aircraft that were actually armed with BVR missiles (and let's not forget, most combat aircraft in that war were not armed with BVR missiles) had decent success with them.
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By: lukos - 2nd September 2014 at 19:16 Permalink - Edited 1st January 1970 at 01:00
Theoretically the current ones can if you pick the target up on IRST but at those kinds of ranges BVR separation is unlikely to be maintainable and a merge is likely.
This is not the case. The main advantage of AESA over PESA is the ability of separate T/R modules to operate on different frequencies and combine frequencies in a single beam. Each T/R module itself usually doesn't change in the middle of a pulse but theoretically there isn't anything preventing such an occurrence and there are developments at large.
But you're only duplicating it after the fact and there's nothing to say the pulse will continue as it started.
Dubious. Operating a 4GHz, you'd be hard pushed to perform a program of any complexity in 400 clock cycles. If it's against a simple non-AESA radar, then that's a different matter. What radar was it against?
Another one was also damaged. What it could also be seen to demonstrate is that RF is part of a wider EM spectrum and RAM clearly doesn't work against the whole spectrum, hence it's unlikely to work equally against the whole RF band either. At extremely high frequencies it will also fall down. MWR and IR Lidar could be a problem for it.
Posts: 6,983
By: obligatory - 2nd September 2014 at 19:17 Permalink - Edited 1st January 1970 at 01:00
It is noteworthy that all A2A engagements are around 5 nm, give or take,
and the give or take is given by if the target is moving away or towards the missile
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By: lukos - 2nd September 2014 at 19:21 Permalink - Edited 1st January 1970 at 01:00
How much of your study focused on the AMRAAM era? Lumping SARH in with ARH is pointless.
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By: obligatory - 2nd September 2014 at 19:23 Permalink - Edited 1st January 1970 at 01:00
difference between SARH & ARH is irrelevant in terms of range,
except autonomous missile have an advantage at close range when the shooter might have problem keeping the nose pointed at target
but would be interesting to compare survivability of the shooter of respective missile
Posts: 2,814
By: Levsha - 2nd September 2014 at 19:30 Permalink - Edited 1st January 1970 at 01:00
US pilots were restricted to attacking enemy aircraft that were in visual range in order to make a positive ID. What that has to do with the real performance of AIM-7 is not clear. Also, BVR missiles of the sixties were, I believe, primarily designed to shoot down bombers - not MiGs.
Posts: 6,983
By: obligatory - 2nd September 2014 at 19:42 Permalink - Edited 1st January 1970 at 01:00
1] the trend is increasing demands of positive ID,
2] the chart indicates the real performance vs piloted (and therefore) non-cooperative targets
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By: halloweene - 2nd September 2014 at 19:50 Permalink - Edited 1st January 1970 at 01:00
Wondering why pilots preferred (ahead of engineers) a new TV channel to a new IR on Rafale's OSF?