With the RAAF selecting JSF, I was wondering if AMRAAM type missiles such as R77,mica,SD10 etc can "see" stealth aircraft like JSF,F22. Does the range of the missile become reduced, or will Awac type aircraft be able to "tell" the missile where to go.Was wondering if the self guidence becomes ineffective....
BVR Missile question
- Thread starter old faithful
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old faithful said:
AMRAAM is dependent on mid-range guidance at BVR... if it's at distance and the AWACS can't see her you likely won't get a kill. If JSF falls into the "basket" (self guidance) then a kill is highly probable. Although that would be a lucky shot if AWACs isn't updating the track. With the relatively low speed of JSF it will make it more difficult to escape the basket, however her reduced radar sig more than makes up for this shortfall.
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thanks mate, but what i mean, is the "basket" gonna be reduced,or is it relativly small anyway?
Against a JSF it will be reduced compared to other fighters. Steps have been taken to reduce radar and heat signatures making her a 5th gen aircraft. JSF will be much more difficult for missiles to acquire on terminal guidance making the basket smaller. Traditionally the basket has been in the 5-7km range but against a JSF it will likely be under 1km. It will be interesting to see what new techniques militaries put into their seekers to find 5th gen aircraft.old faithful said:
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im guessing that mica IR is guided by data link untill the IR seeker locks on....that might be the way to go against stealth tech. Cause i think that the radar on board AA missiles like SD10 and R77 will have trouble "finding " aircraft like JSF and F22 untill its to late.
powerslavenegi
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Correction
A slight correction.... Active radar homing is not the only guidance method of a missile. It is most often used during the terminal phase of the engagement, mainly because since the radar transceiver on the missile aint big and powerful enough to engage the target from the poitn of launch itself(in case of bvr eng). Hence they require command guidance with an inertial navigation system (INS) in order to fly from the launch point until the target is close enough to be detected and tracked by the missile radar. The missile therefore requires guidance updates via a datalink from the launching platform up until this point.MBDA's Mica is reported to have a range in vicinity of 80 Km which is inferior to AIM120 and Meteor.As for engaging targets like F-22 and jsf ,the conversation will be meaningful only when we have some declassified info about their RCS,until then we all can just speculate.old faithful said:
old faithful said:
IMO, given that AMRAAM initially operates in a very high PRF to maximize detection thresholds irrespective of aspect or scan dwell as it looks through the seeker cube, the increased ERPS of this mode should be enough to get lockon at near conventional range before settling back to MPRF for terminal closure. It should also be noted that the missile may well be lofted to see 'hotside' target features and if the stealth airframe starts to maneuver against it in the terminal mode (via AAR-56 or EODAS alerting), that the signature thresholds may well increase regardless as the pilot flat-plates the airframe and puts G-vortices on it.
Given I was told that seeker acquisition could begin as early as 10-12nm, it would make sense if 'halving the distance' allowed less time for the threat to initiate countermeasures. I think Bear's engagement with the two MiG-29s over Serbia may be telling in that they started to turn off just about the time he could see them increase their visual profile. Whether they thought they were nothcing on an activated seeker or saw him I don't know but the distances (6-8nm IIRR) vs. launch (12nm?) seem to indicate that even with supersprint boosting the AMRAAMs total engagement envelope may be significantly less than the 80-100km suggested.
Constant command guidance to impact may be an option but it would be a tricky one, IMO, because the target RWR may well pickup the uplink and before the C7/D the missile had no real way to give it's own location relative to the target.
The inevitable day will come when some genius reinvents the wheel (AIM-155) as a function of using a truly large optics package plus GCI to find a stealth fighter and then flying out a missile along the boresight line until it can take over it's own guidance with dual spectrum homing in which the superior angular resolution of an IR cell is matched to a very basic 'range only' RF seeker that operates at sufficiently low or high bandwidths (C or Ka/W) to get -something- off the target.
Which is why I believe in the F-22 but not the F-35. Because the F-35 is an F-117 with Radar. It _cannot_ maneuver and maintain LO. And it is not moving fast enough to start with to truly exploit the high-fast option in slingbombing targets from 80-100nm out and thus avoiding the standing CAP or QRA force altogether.
People need to remember one other thing: If the ABL works as advertised, it will likely be a line of sight weapon against manned aircraft operating above 20-25,000ft. That's a minimum 1,000km from a 30-40,000ft orbit. Thus the definition of 'what is an air superiority fighter' may well have to change to 'What is cheap enough to lose that you can afford to go head to head with the 30 shot counts of the ABL and still have enough left to try and stop the stealth force afterwards...'.
IMO, nothing manned will come close to achieving this on a 2-3,000 dollar chemical expenditure per laser blast. You will _have to_ shift to hunting weapons that can saturate the field in numbers on the order of 50-100 per mission and at that point, you're bleeped because they will come on like Napoleonic Line Infantry, sweeping a corridor 100miles wide and 10 or more deep at a sustained Mach 1.2 or better themselves.
KPl.
Oh found a very interesting question.
To make it simple it would depend on what aspect of the aircraft the missile is approaching. RCS reduction tends to be maximized around the frontal aspect of the aircraft, so if the missile is coming from below or above in a lofted angle, it opens up the radar signature of the target. Don't know how many Russian missiles are doing this, but lofting is an old trick since the AIM-7M.
And again, AWACS detection will also be affected as to what aspect and direction the VLO target is to the AWACS. Suffice to say if the VLO aircraft detects the AWACS emissions and general bearing, he can point his nose at it, bringing his frontal aspect into the direction of the AWACS, and that can make him disappear.
I am starting to think that SARH methods may be heading for a comeback. SARH may have some advantage against VLO targets.
To understand stealth, basically you're trying to reflect radar energy away anywhere but the source emitter. This is because radars are monostatic, meaning both emitter and reciever are the same station. So our monostatic radar would be represented by the symbol ER. ARH is essentially monostatic.
So what do you do? You decouple emitter and reciever from one station into two. Now that becomes bistatic radar. If you have multiple emitters and recievers all over the place in a network, it becomes multistatic.
Because its hard to determine where the reciever is now, you cannot anticipate by faceting where you can direct the radio energy into. Certainly the design is reflecting energy away from the emission as it was meant to, but it also means that another station located not in the same location as the emitter would pick it up.
With SARH, the emitter would be from the source plane, but the receiver is seperately on a missile. Essentially the principle is bistatic. So long the missile is not flying from the same direction as the emitter, assuming it takes a lofted flight path, it can pick up the signals that were reflected away from the direction of a source emitter.
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Cheers crobato,good answer! a lot to be said for irst!
The Fat Pigeon
This is somewhat wishful thinking, don't you think, particularly from the back end.
See -
http://www.irisresearch.com/radargame.html
This is a good primer for anyone interested in coming to terms with LO.
As for performance, not only 'relatively low speed' but sluggish in acceleration - the 'design target' for standard test 0.8M to 1.2M @ 15k ft was 42 seconds and that was before the aircraft got the fats and the weight went up.
The marketeers are writing cheques that the poor little (tubby) jet just won't be able to cover. What a pity. This could have been such a great program.
Naturally, low subsonic accel will be better (more excess thrust) but the F135/136 have big fan and from back on the power speeds to full cob will have spool up times to consider. However, what is the relevance of fast initial accel from low sub. Sorta like saying that the parking brake works well.
Back on the LOs. Off band, the back end won't be LO. With burner lit, the back end won't be LO.
There are particular reasons why the B-2, F-117 and F-22 don't have big, round Con-Di nozzles.
As for that little thing called the ability to surprise, for the standard four ship JSF flight with its entourage of AWACS, tankers and, if in strike mode, fighter escorts, forget it!
This is somewhat wishful thinking, don't you think, particularly from the back end.
See -
http://www.irisresearch.com/radargame.html
This is a good primer for anyone interested in coming to terms with LO.
As for performance, not only 'relatively low speed' but sluggish in acceleration - the 'design target' for standard test 0.8M to 1.2M @ 15k ft was 42 seconds and that was before the aircraft got the fats and the weight went up.
The marketeers are writing cheques that the poor little (tubby) jet just won't be able to cover. What a pity. This could have been such a great program.
Naturally, low subsonic accel will be better (more excess thrust) but the F135/136 have big fan and from back on the power speeds to full cob will have spool up times to consider. However, what is the relevance of fast initial accel from low sub. Sorta like saying that the parking brake works well.
Back on the LOs. Off band, the back end won't be LO. With burner lit, the back end won't be LO.
There are particular reasons why the B-2, F-117 and F-22 don't have big, round Con-Di nozzles.
As for that little thing called the ability to surprise, for the standard four ship JSF flight with its entourage of AWACS, tankers and, if in strike mode, fighter escorts, forget it!
weasel1962
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I was refering to the ability of LRR to track it at distance. If BVRAAMs don't recieve mid-course guidance updates it doesn't matter how much heat she puts out as the seeker won't even be in the ball-park.
Exactly, there was a time when RAF tornados were switching to amraams before the avioncs were modified to give out midcourse corrections. Result was that even the older sky flash missiles (kinda like aim7) that amraam was supposed to replace had better hit percentage than non-corrected aim120.
I do believe that, just like with IIR sensors replacing radar ones in new gen of anti ship missiles, IIR may also be used on BVR AAMs in the future. Especially against low RCS targets. Of course, no one is saying that one can cram as capable IR sensor in a small missile head as one could in a plane itself, nor is anyone saying that such a seeker could determine range to target when in BVR mode... BUT, there doesn't seem to be a better way to go against stealthy targets. Various amraam-class seekers are lucky if they get a lock-on on f22 beyond a mile or two anyway. Basically useless.
On the other hand, imaging IR coupled with a decent software/hardware will lock on any high flying target up to visual range, with telephoto camera easely 10 km, more so in clear weather. Imaging part will also be able to determine range for terminal guidance, though of course other means would be needed to provide heading (and in flight corrections) and range just upon launch. That won't be achievable without low wavelength radar or/and multistatic sensor network.
I do believe that, just like with IIR sensors replacing radar ones in new gen of anti ship missiles, IIR may also be used on BVR AAMs in the future. Especially against low RCS targets. Of course, no one is saying that one can cram as capable IR sensor in a small missile head as one could in a plane itself, nor is anyone saying that such a seeker could determine range to target when in BVR mode... BUT, there doesn't seem to be a better way to go against stealthy targets. Various amraam-class seekers are lucky if they get a lock-on on f22 beyond a mile or two anyway. Basically useless.
On the other hand, imaging IR coupled with a decent software/hardware will lock on any high flying target up to visual range, with telephoto camera easely 10 km, more so in clear weather. Imaging part will also be able to determine range for terminal guidance, though of course other means would be needed to provide heading (and in flight corrections) and range just upon launch. That won't be achievable without low wavelength radar or/and multistatic sensor network.
Where are you guys getting the numbers from claiming an AMRAAM will only get a lock a mile or two away from a F-22?
Stealth doesn't reduce detection range as much as you think.
Radar like sound energy requires multiple times the energy to double the range of the radar. If you reduce the radar cross section of a given aircraft to 1% of its original size if you could detect the original aircraft at 100 miles doesn't mean you will now detect it at 1 mile. It will be detected much sooner, definitely more than 10 miles away.
So based on this if an F-22 can detect another F-22 at 50miles. If the AMRAAM seeker is only 1% as powerful as the F-22 radar it would get a lock on well before 1 mile away, probably up to 5 miles away and the AMRAAM would be locked on the F-22, definitely useful against other stealth aircraft.
On another note, people also say that the AMRAAM is too short ranged for the F-22, i dont think so. A long range missile like the Pheonix would be good for only shooting down enemy AWAC's and transports. These large aircraft you detect long before you get within missile range so it would be handy to be able to shoot a missile from a very long distance away. However in the coming decades the enemy will start to produce stealthy planes, assuming these future enemy aircraft aren't as stealthy as the F-22 and their radar is inferior then the F-22 will only first detect enemy within AMRAAM firing distance.
All that really needs to be done is to put a more powerful seeker on the AMRAAM just like how radars on fighters are also getting more powerful.
Stealth doesn't reduce detection range as much as you think.
Radar like sound energy requires multiple times the energy to double the range of the radar. If you reduce the radar cross section of a given aircraft to 1% of its original size if you could detect the original aircraft at 100 miles doesn't mean you will now detect it at 1 mile. It will be detected much sooner, definitely more than 10 miles away.
So based on this if an F-22 can detect another F-22 at 50miles. If the AMRAAM seeker is only 1% as powerful as the F-22 radar it would get a lock on well before 1 mile away, probably up to 5 miles away and the AMRAAM would be locked on the F-22, definitely useful against other stealth aircraft.
On another note, people also say that the AMRAAM is too short ranged for the F-22, i dont think so. A long range missile like the Pheonix would be good for only shooting down enemy AWAC's and transports. These large aircraft you detect long before you get within missile range so it would be handy to be able to shoot a missile from a very long distance away. However in the coming decades the enemy will start to produce stealthy planes, assuming these future enemy aircraft aren't as stealthy as the F-22 and their radar is inferior then the F-22 will only first detect enemy within AMRAAM firing distance.
All that really needs to be done is to put a more powerful seeker on the AMRAAM just like how radars on fighters are also getting more powerful.
Where are you guys getting the numbers from claiming an AMRAAM will only get a lock a mile or two away from a F-22?
Stealth doesn't reduce detection range as much as you think.
Since the F-117 first flew radars have increased in power, not by 10 times but well over 100 times in power. So if you reduce the radar cross section to 1% of the original size you just need a radar 100 times more powerful. They have already done this. The Aegis Mk7 system is well over 100 times more powerful than the radar on the F-22.
Radar like sound requires multiple times the energy to double the range of the radar. If you reduce the radar cross section of a given aircraft to 1% of its original size if you could detect the original aircraft at 100 miles doesn't mean you will now detect it at 1 mile. It will be detected much sooner, definitely more than 10 miles away.
So based on this if an F-22 can detect another F-22 at 50miles. If the AMRAAM seeker is only 1% as powerful as the F-22 radar it would get a lock on well before 1 mile away, probably up to 5 miles away and the AMRAAM would be locked on the F-22, definitely useful against other stealth aircraft.
On another note, people also say that the AMRAAM is too short ranged for the F-22, i dont think so. A long range missile like the Pheonix would be good for only shooting down enemy AWAC's and transports. These large aircraft you detect long before you get within missile range so it would be handy to be able to shoot a missile from a very long distance away. However in the coming decades the enemy will start to produce stealthy planes, assuming these future enemy aircraft aren't as stealthy as the F-22 and their radar is inferior then the F-22 will only first detect enemy within AMRAAM firing distance.
All that really needs to be done is to put a more powerful seeker on the AMRAAM just like how radars on fighters are also getting more powerful.
Stealth doesn't reduce detection range as much as you think.
Since the F-117 first flew radars have increased in power, not by 10 times but well over 100 times in power. So if you reduce the radar cross section to 1% of the original size you just need a radar 100 times more powerful. They have already done this. The Aegis Mk7 system is well over 100 times more powerful than the radar on the F-22.
Radar like sound requires multiple times the energy to double the range of the radar. If you reduce the radar cross section of a given aircraft to 1% of its original size if you could detect the original aircraft at 100 miles doesn't mean you will now detect it at 1 mile. It will be detected much sooner, definitely more than 10 miles away.
So based on this if an F-22 can detect another F-22 at 50miles. If the AMRAAM seeker is only 1% as powerful as the F-22 radar it would get a lock on well before 1 mile away, probably up to 5 miles away and the AMRAAM would be locked on the F-22, definitely useful against other stealth aircraft.
On another note, people also say that the AMRAAM is too short ranged for the F-22, i dont think so. A long range missile like the Pheonix would be good for only shooting down enemy AWAC's and transports. These large aircraft you detect long before you get within missile range so it would be handy to be able to shoot a missile from a very long distance away. However in the coming decades the enemy will start to produce stealthy planes, assuming these future enemy aircraft aren't as stealthy as the F-22 and their radar is inferior then the F-22 will only first detect enemy within AMRAAM firing distance.
All that really needs to be done is to put a more powerful seeker on the AMRAAM just like how radars on fighters are also getting more powerful.
No numbers have or ever will be published by any kind of official source. Like here, they are all a product of rough calculatons based on radar equation and various comparable data. Assuming that apg77 has peak power of 25kw, which seems to be on the high end of guesses that are floating around, and assuming rcs of 0.001 m, which is again, not the smallest number thrown around, detection range falls around just 15-17 nm, 20-22 at most if it can search with 10 cm wavelengths.
I haven't found amraam radar power but R-77's radar is quoted to be just under 800 w. And russians have traditionally had more powerful seekers to compensate for lower gain of their radars. One has to keep in mind that all those seekers work in 2-3 cm long wavelengths, which is very good for precise tracking but not as good for maximum range. Also, figures of 20 km are often cited as tracking ranges for amraam class seekers on usual 4th gen non stealthy targets.
To get a double increase in range, one has to increase radar power by a factor of 16. That is not a feat easely done on a any missile, let alone a small form missile of amraam class.
I haven't found amraam radar power but R-77's radar is quoted to be just under 800 w. And russians have traditionally had more powerful seekers to compensate for lower gain of their radars. One has to keep in mind that all those seekers work in 2-3 cm long wavelengths, which is very good for precise tracking but not as good for maximum range. Also, figures of 20 km are often cited as tracking ranges for amraam class seekers on usual 4th gen non stealthy targets.
To get a double increase in range, one has to increase radar power by a factor of 16. That is not a feat easely done on a any missile, let alone a small form missile of amraam class.
I thought it was around 10-16 times, wasn't exactly sure
You can use the calculation in reverse as well, which gets my point across. If the radar has a 16th of the power its range is only half, most people think it would be much less than half. Thats why the AMRAAM will be able to detect a stealth aircraft much sooner than expected..
If the AMRAAM has 256th of the power of an F-22 radar its detection range is only a quarter of the F-22's detection range. So i was pretty much spot on, if an F-22 can detect another F-22 at 40 miles and the AMRAAM has 256th of the power (very small) it will get a lock on at 10 miles. If the AMRAAM seeker was only say a 50th of the power, then it would be getting a lock on at nearly 20 miles.
So there you go, the AMRAAM wont have any trouble getting a lock onto a stealth aircraft.
I could gurantee that a Navy Aegis radar would see an inbound F-22 clear as day from 50 miles away. But then a SDB would already be on its way, so the F-22 could have avoided detection completely by slinging the bomb from high speed and altitude before getting close enough to be detected.
Yet another disadvantage of the JSF as the JSF will have to get nearly twice as close to its target to drop a small diameter bomb, so thats 16 times more likely to be detected than an F-22. Thats also asssuming the radar cross section of both aircraft is the same too, if the JSF had a radar cross section 10 times bigger than an F-22, the JSF will now be 100 times more likely to be detected on a bombing mission than a JSF.
Another reason they should cancel the JSF.
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Though no one here really has accurate info, some figures are more likely than others. To get into the whole game of guessing radar ranges we need to know power of radar, gain, operating wavelength and RCS of target. That last one is actually dependant on radar wavelength but all the info that's ever given or hinted at for various plane's RCS is given as final RCS for some unindentified wavelength, presumably somewhere in 5-10 cm as most air search radars use those wavelength.
For f-22, only official figure given by USAF was RCS of a marble. It didnt say what kind of marble, what size, under what wavelength. It could range from 0.002 to 0.0001 square meters. With jsf it was said a golf ball, which is quite precise in size, so that would suggest range of 0.014 for large wavelengths and possibly as low as 0.001 for small wavelengths like that of amraam seeer.
While we don't know precise values of raptors and amraams radars' power, we can suspect they are in 15-25 kw and 700-900 w range, respectevely. So that is some 25 times less power in amraam than it is in apg-77. There is also difference in wavelength which we sort of know but there's radar gain too, which is harder to guess.
Radar equation then gives out the figures i mentioned before, just some two or so nautical miles for amraam class seeker and not much more than 20 nm for apg77, in ideal circumstances. Yes, amraam has only ten times smaller range but it also has some 25 times weaker radar. While amraam can in theory lock onto f22, in practice its unlikely target will be so steady and peaceful to allow the amraam launching plane to achieve that lock on.
Assuming publicized (but not necesarrily true) values for spy-1 radar, we would get detection range of some 40 nm. so yeah, that's basically 50 statute miles like you were guessing. f-35 would be detected at over 70 nm. It is, though, questionable if either, especially raptor, could be targeted by either ship missile guidance illuminators or missile's own radars.
For f-22, only official figure given by USAF was RCS of a marble. It didnt say what kind of marble, what size, under what wavelength. It could range from 0.002 to 0.0001 square meters. With jsf it was said a golf ball, which is quite precise in size, so that would suggest range of 0.014 for large wavelengths and possibly as low as 0.001 for small wavelengths like that of amraam seeer.
While we don't know precise values of raptors and amraams radars' power, we can suspect they are in 15-25 kw and 700-900 w range, respectevely. So that is some 25 times less power in amraam than it is in apg-77. There is also difference in wavelength which we sort of know but there's radar gain too, which is harder to guess.
Radar equation then gives out the figures i mentioned before, just some two or so nautical miles for amraam class seeker and not much more than 20 nm for apg77, in ideal circumstances. Yes, amraam has only ten times smaller range but it also has some 25 times weaker radar. While amraam can in theory lock onto f22, in practice its unlikely target will be so steady and peaceful to allow the amraam launching plane to achieve that lock on.
Assuming publicized (but not necesarrily true) values for spy-1 radar, we would get detection range of some 40 nm. so yeah, that's basically 50 statute miles like you were guessing. f-35 would be detected at over 70 nm. It is, though, questionable if either, especially raptor, could be targeted by either ship missile guidance illuminators or missile's own radars.
weasel1962
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