PAK-FA and FGFA Thread

[SaiK]

http://warezbul.com/camouflage-patterns ... ttern.html
More here^

--

Good post kanson. Will make us think for a while till we obtain a wind tunnel data on such designs.

[Gaur]

^^
Those are army camos. You would not want to see IAF flying FGFA in jungle camo, would you?
Anyways, thanks for the effort.

[SaiK]

not really, imho. eg: http://media.defenseindustrydaily.com/i ... -37_lg.jpg

and why not the no.053 from the warezbul link?

or the bonding 007 would be near IAF colors.

[Gaur]

^^
Yeah, well I really hate Russian camos on fighter aircrafts. In any case, I want to visualize final FGFA configuration which should have RAM coating rather than some generic paint camo.
That is why I want to go for a rough and weathered and grainy dark grey camo like that of YF-23.
http://upload.wikimedia.org/wikipedia/c ... axiway.jpg
http://upload.wikimedia.org/wikipedia/c ... t_view.jpg
Look how weathered and subtly grain, lined the grey colour is. This gives the appearance of non reflectiveness and hence looks very good on a stealth plane. Think how flat engines twin seater FGFA will look in that colour scheme. But I am unable to paint that weathered look on standard dark grey color.

However, if that cannot be achieved, I will have no choice but to finally go for F-35 like smooth dark grey colour scheme. IMHO, that would look horrible on PAK-FA.
I would have cropped some large resolution YF-23 image to get the pattern but the problem is that the final texture resolution "must" be over 1000*1000 pixels (though 2000*2000 pixels is ideal) with no bends and uniform lightning all over. I am sadly not able to find a YF-23 picture with which I can do that.

[vardhank]

kanson, thanks for the explanations. how about say additional TVC nozzles or the existing improved 360*TVC as a counterbalance for loss of control during AoA maneuvers?

didn't x31 used paddles for vectoring? any use here to improve AoA?

No. Here at high AoA, as we infer/assume that the engine stalls before wing, the problem is not with control surfaces during AoA. It is the loss of engine power. Fighter planes are not like gliders which can float even without power. So with loss of power, it is just a dead weight that is expected to fall from sky. When engine fails at high AoA in this situation, control surfaces are still active and can be used to stabilize the aircraft from the spin while attempting to re-light the stalled engine.

But then, this rendering shown has LERX and then wing fence like structure/depression leading to inlet. So we can't simply conclude that it can't do high AoA. How high the AoA it can do, can only be determined in wind tunnel test. In addition new techniques can be used to keep the air flow to the engine. But then we are only talking about the inlets.

Paddles are another way of vectoring thrust. It is similar to jet vanes used in missiles. But then it is of any use only when there is enough thrust from the engine. When engine stalls, what is the use of such devices to attain high AoA?

Heh... what about inlets like those in the rendering, but which can open up for high AoA situations? Loss of stealth, obviously, but am I in any way right in thinking that most high AoA situations could be considered out of the ordinary, eg during WVR combat, when stealth can be abandoned?

[Indranil]

^^^ Open up where?!!

[Gurneesh]

At the bottom like conventional fighters....

[vardhank]

^^^ Open up where?!!

sleek recessed intakes like in the rendering, which open up like the pop-up headlamps in '80s sports cars or the metal pouring flaps on a box of chocolate hail, to increase the area of intake and reduce the angle... only these would probably be more sort of telescopic (extending mostly forward instead of upward like pop-up headlamps, if you see what i mean) (gah, i'll try and draw these )

[Indranil]

Gurneet, So you want to have two air intakes? The bottom one is closed in leveled flights? What will you do with the top intake when handling high AoA?

Think about the complexity of air flow when both one or both are partially open.
Now we will have two times the volume for the air intakes.
What is the requirement for such complexity?

Even if you leave aside high AoA, that kind of air intake is not going to work well in level flight. For having the inlets totally covered by the body of the plane, the plane has to be curved such a lot. If you have such a curved body and the intakes pushed so further back, you will have to have a very wide intake for enough airflow. Or to keep the curvature of the body low and use a slit like air intake as in the artists impression. In that case, why would the air want to enter in those slits, it would like to skim over the top with the boundary layer.

So good looks 10/10. Functioning

[Indranil]

Vardhan Sahab, I understand what you are saying. That would be easier to implement with the AoA (:)) of the engine intake (or the top part of it with circular skirting by the side) as a function of the planes AoA.

However, you would need powerful hydraulics for this. Power hydraulics are big occupying space, have a weight penalty and are typically slow. So even if you could produce a hydraulic which could be powerful as well as prompt enough, you would be creating a huge maintenance headache.

Besides, think of the drag created by these extended intakes. Thats not good at high AoA. Besides, such an extension will act as a control surface.

So you would have created a higher drag, lower TWR, maintenance heavy aircraft. any logic to justify the same, when the same functionality can be achieved with none of the side effects.

[Sumeet]

^^
Because LM has never said that it can. People are just basing their speculations upon vague statements. Till now, it has never been claimed by NG that DAS sensors are anything other than typical IRST/OLS systems which are basically FLIR and a laser rangefinders. Though technically speaking, any IRST/OLS may be able to guide missiles but that would not be very efficient. First of all, missile seeker's performance will far outmatch that of IRST/OLS simply because it will be much closer to the target. The performance depriciation will be even more huge if there is rain, fog etc. Secondly, IRST/OLS will view the target from a different perspective view than that of missile head. So, the IRST/OLS has to use its laser rangerfinder and process the accurate co-ordinates of the target and continuesly send it to the IR missile. But the IR AAM does not understand space co-ordinates. So, the information has to be further processed so that the missile seeker is tricked to see ir signature in the proper place. But even the laser rangefinder will not work properly in smoke and fog.
In short, you can guide a missile using IRST/OLS if you want to, but there is simply no need. Why try complicated alternatives when there is a simple way present.

Frankly, I do not understand why people are so disappointed that DAS cannot guide missiles. DAS was mainly developed for situational awareness and hopefully it can do that job well enough. Why does it have to do every other job?

Added Later: As I have said earlier, it is not that it cannot be done. I am simply saying that, IMO, there is no need (also it may prove to be even less efficient). However, LM may believe differently and use DAS to guide IR missiles anyways. But if so, it could only be believed if someone could provide us with proper reference. If that is provided, then I would be happy to be educated. But till then, I do not understand the need to do speculations based on some vague statements.

Two points:

1) DAS is not from LM.
2) watch this video http://www.es.northropgrumman.com/solut ... video.html

[Gaur]

^^

Two points:

1) DAS is not from LM.

Never said that it is.

Because LM has never said that it can. People are just basing their speculations upon vague statements. Till now, it has never been claimed by NG that DAS sensors are anything other than typical IRST/OLS systems which are basically FLIR and a laser rangefinders.

NG= Northrop Grumman
I just named LM first because it leads the design team of F-35.

2) watch this video http://www.es.northropgrumman.com/solut ... video.html

Skip to 1:40. How does F-35 image, detect and ID AAAs? EOTS & AESA.
Even for A2A scenarios, nowhere does the video say that DAS provides tracking info to the AAM. It just says that it eliminates the possibility of surprise attack by providing better situational awareness.

Added Later: I think that DAS may indeed have some role in A2A targeting. As I had explained in my previous post, it is much better to use missile IR than DAS for target tracking. However, before launching IR AAM, the target has to first detected by Aircraft. That is usually done by Radar because it is more capable than IRST/OLS.
Unfortunately, F-35 has no rear facing radar, so it would have to rely on DAS IRST for initial detection and after that the missile can do the tracking. At least, that is my understanding of how it works.

[vardhank]

Vardhan Sahab, I understand what you are saying. That would be easier to implement with the AoA (:)) of the engine intake (or the top part of it with circular skirting by the side) as a function of the planes AoA.

However, you would need powerful hydraulics for this. Power hydraulics are big occupying space, have a weight penalty and are typically slow. So even if you could produce a hydraulic which could be powerful as well as prompt enough, you would be creating a huge maintenance headache.

Besides, think of the drag created by these extended intakes. Thats not good at high AoA. Besides, such an extension will act as a control surface.

So you would have created a higher drag, lower TWR, maintenance heavy aircraft. any logic to justify the same, when the same functionality can be achieved with none of the side effects.

Who you calling Sahab?

Honestly? I pulled that out of the Musharraf. I honestly have no idea whether something like that would work - I tend to come up with wild ideas and let sensible people sort out the details.

Wild idea No 2: Instead of flaps that extend, maybe you could have flaps that retract, creating a larger inlet. It probably wouldn't help much with the angle, but it might (and again, this is Musharraf aerodynamics) allow a greater volume of air to be sucked in. The quality of the flow, turbulence etc, are not things I'd know very much about. If it doesn't work, oh well. If it does, you've got a good solution for improved stealth and avoiding debris from unprepared landing strips.

[SaiK]

wow.. from divertless to popups. who says we can't invent.

[Indranil]

Vardhan,

I couldn't understand what you meant by flaps which retract and provide greater area.

[Austin]

I would like to know how IR sensors can track and cue missle to the target without ranging information which has to be fed to the missile and updated , in ols it is done by LRF which works in conjuction with IR sensors , das TI sensors cannot range target it would still need LRF or radar to range the target.

[Karan M]

^^

Kinematic Ranging.

http://spie.org/x648.html?product_id=156615

Pirate IRST has similar mode. Not as accurate as LRF but should help.

DTI, December 09, Bill Sweetman "Two EFs can detect, track, and range targets by sharing IRST information over a datalink or a single aircraft can calculate range using dynamic ranging flying a series of weaves and calculating range from the change in the targets bearing".

"IRST is a complement to radar and range is sensitive and depends on many factors including weather, target speed and whether it is using afterburners."

[Sumeet]

Austin,

Your question about ranging in absence of LRF is also answered here.

^^
I just named LM first because it leads the design team of F-35.

Cool I got confused because I read your post in conjunction with abhik's post.

2) watch this video http://www.es.northropgrumman.com/solut ... video.html

Skip to 1:40. How does F-35 image, detect and ID AAAs? EOTS & AESA.

That is for ground targets. Based on information provided by DAS to the mission computer, the sensor fusion architecture & software can enable EOTS or AESA or Both to detect, ID target for countermeasure.

Technically, the same can be done for any air borne target [BM, fighter, missile or UAV etc] provided it is in FoV of EOTS & APG-81 Radar.

Even for A2A scenarios, nowhere does the video say that DAS provides tracking info to the AAM. It just says that it eliminates the possibility of surprise attack by providing better situational awareness.

Those missiles didn't do a turn magically. They were told to do so. Radar & EOTS didn't do that, so who else can do that ? Answer --> DAS.
IRST function of DAS is well documented by NG. In fact NG itself says it has fire control capability. Please see link provided by Kanson earlier. 21st century IRST from Lockheed for F/A-18 E/F also has fire control capability.

Lockheed's IRST for F/A-18 E/F

Check second page they clearly mention "Weapon quality passive ranging".

Modern day IRST can not only get target bearing but also its range using Passive ranging. Please note ranging done via LRF is not passive since its vulnerable to be detected by LWR just like Radar ranging is not passive as radar can be detected by RWR.

So what does Passive ranging means --> Ranging via listening to radar signals like RWR ALR-94 in case of F-22 raptor. For IR based passive ranging there are multitude of techniques other than Kinematic Ranging pointed to by KaranM.

Small note here: One definition of passive ranging is provided by this paper published by folks at NASA, Ames Research Lab.
"Passive ranging consists of processing a sequence of images using techniques based on optical flow computation and recursive estimation."
Source: Computer architectures for a real-time passive ranging algorithm, IEEE
Sridhar, B. ; Suorsa, R.E. ;
NASA Ames Res. Center, Moffett Field, CA

1) A sliding-mode based guidance law for intercepting missile with passive ranging law

2) A modified method of passive ranging using optical flow of target infrared images
[This is based on one way or definition of doing passive ranging, see that NASA paper published in 1993.]

A modified method of passive ranging from optical flow (OF) of infrared target was proposed. The range was achieved through analyze of the movement of the imaging sensor and the OF of the target. As the traditional passive ranging algorithm was only using the definition but no OF in the range estimation. The resolution of the imaging system will influence the ranging result strongly. The OF of the potential target image from an adequate length of temporal changing rate. The direct use of OF in range estimation is supported by a modified 3D gradient operator. We present the OF parameters clustering method to achieve more robust result. Firstly, we use median filter to remove the wildpoints and outliers of the image sequences. Secondly, the moving target was segmented with auto-adaptive threshold algorithm. The whole target was obtained by the OF of the pixels inside the smallest rectangle that surrounds the target. A range expression at each pixel may directly calculate from the pixel location, the motion parameter and OF. Finally, the range to the target is the average range of the target area pixels. The experiment result shows that the algorithm can be applied to the infrared target passive ranging applications.

3) Research of the aerial target ranging on single-station dual-band IR imaging system


A quick recap:

1) DAS can search, detect and track targets is well proven. [Both documented in writing & shown in the video]
2) Passive ranging is an alternative technique to Laser Ranging for IR application and it exists in real world products
3) Lockheed has implemented weapon quality passive ranging technique on IRST for F/A-18 E/F Super Hornet
4) Northrop has specifically mentioned fire control capability for DAS
http://www.es.northropgrumman.com/ASD/combat/F-35.html

It warns the pilot of incoming aircraft and missile threats as well as providing day/night vision, fire control capability and precision tracking of wingmen/friendly aircraft for tactical maneuvering.

Fire control capability is not possible unless DAS can provide both a) Bearing data b) Range data to weapon.

5) Northrop has passive ranging technology.
Check Mr. Ganguly's resume
http://motion.mee.ucsb.edu/~aganguli/resume.pdf
Project: Range estimation of moving objects using monocular electro-optical/infra-red cameras
Sponsor: US Air Force through Small Business Innovation Research (SBIR) grant
Responsibility: Overall technical lead and co-Principal Investigator.
Achievements: Led a team of 5 engineers and scientists to successfully solve a three decade old problem. Successfully collaborated with Northrop Grumman Corporation to develop an advanced technology demonstration plan which received additional $500000 funding from the Air Force. This is also the first project
at UtopiaCompression to receive non-SBIR government funding.
Collaborators: Northrop Grumman Corporation


http://www.es.northropgrumman.com/solut ... alq218.pdf
From above:

“The ALQ-218 utilizes a unique combination of short, medium and long baseline interferom¬eter techniques with a patented passive ranging algorithm to provide geolocation of emitters for cueing jammers”

Likewise angular location and range estimation via passive ranging can be performed easily by DAS to cue HOBS IIR WVR missile. Otherwise no way those missiles can magically turn around like that and seek target aircraft. If I am not mistaken IIR has higher angular location than a Radar.

Added Later: I think that DAS may indeed have some role in A2A targeting. As I had explained in my previous post, it is much better to use missile IR than DAS for target tracking. However, before launching IR AAM, the target has to first detected by Aircraft. That is usually done by Radar because it is more capable than IRST/OLS.

Unfortunately, F-35 has no rear facing radar, so it would have to rely on DAS IRST for initial detection and after that the missile can do the tracking. At least, that is my understanding of how it works.

An IIR missile track the target only after it has detected it. Till then its dependent on sensor cueing from its launch aircraft; which in this case happens to be DAS. EOTS cannot see above the plane passing through JSF and Radar cannot see anything behind the plane passing via nose cone & cockpit intersection.

In that part of the sphere, DAS is responsible for target search, detection, tracking on detection, finding bearing and ranging and passing it onto IIR WVR missile like AIM-9X operating in lock on after launch mode. It has to guide the missile till missile's own IIR seeker can detect target, start tracking it and acquire lock on it. Then missile will do rest of stuff autonomously.

Missile cannot do searching, tracking independently since its has limited FoV. Even for active radar guided missiles, the X-Band fire control radar keeps updating missile's AR seeker via a data link till missile acquires a target lock after which it can autonomously go after the target.

6) JSF - "Maneuvering is Irrelevant"

"Moreover, DAS is expected to track with enough accuracy and tenacity to permit a safe high-off-boresight, lock-on-after-launch (LOAL) missile shot with any datalink-equipped missile. Indeed, Northrop Grumman's DAS business development leader, Pete Bartos - who was part of the initial USAF JSF requirements team - says that this was basic to the F-35 design and the reason that it did not need maneuverability similar to the F-22. Rather than entering a turning fight at the merge, the F-35 barrels through and takes an over-the-shoulder defensive shot. As a Northrop Grumman video puts it, "maneuvering is irrelevant"."

7) Also, listen to that video again @ 2.18 onwards. "With DAS and High off boresight weapons F-35 can have a kinematic advantage ...." Check what the missile is doing when he talks about it.
Video Link for EO DAS

[shiv]

Heh... what about inlets like those in the rendering, but which can open up for high AoA situations? Loss of stealth, obviously, but am I in any way right in thinking that most high AoA situations could be considered out of the ordinary, eg during WVR combat, when stealth can be abandoned?

I am no expert and you can consider this as "blind leading the blind".

As far as I know the airflow at high AoA is is critical to keep the engine running. Engines do run on the ground so I suppose engines can run even if air speed becomes zero in some situations. I am guessing that sudden high AoA maneuvers disrupt the airflow so that the mass of air per unit time entering the engine is disrupted leading to starvation within the engine and the engine flaming out.

The point is that it is the behavior of the engine when suddenly starved or airflow rather than the shape, geometry and size of the inlet that matters. After all the engine may run perfectly well on the ground no matter what the shape and size of the intake is, provided it is adequate. Fiddling with the intake may be of less use than having a forgiving engine.

I believe that high AoA situations are not restricted to combat maneuvers but are a day to day affair every time an aircraft lands. This may be particularly acute in some situations of steep landing approach, high altitude (Himalayas) and short runway (alternate airfield, battle damage). Another high AoA situation would be slow flying to formate with a slow flying aircraft.

As always I am willing to be corrected by gyanis if any. But I guess this is OT for this thread.

[Avarachan]

Sumeet, thanks for doing all this research and finding these links.

[Austin]

Sumeet , Great Post !

That makes things clear with passive ranging , this should give JSF a good capability with WVR fights an all passive approach to dog fight.

Although they take things to extreme by making statements like "Maneuvering is Irrelevant".

I had asked this question to Peter Goon from APA and he had replied to me , below is his the reply

wrt your proposition – “. . . coz a HOBS missile can always outmanouvere the target.”

Not so. Do the math and you will see it does not take much manoeuvring on the part of even an agile target to evade/dodge, say, the AIM-120 – even the kinematic/aerodynamic capabilities of the AIM-120D. Extreme agility just makes this a whole lot easier, and that’s all before you consider the effects of EW ECM, etc.

Firing from a HOBS position only makes it harder for the missile. Every turn the missile has to make reduces the somewhat finite energy able to be incorporated into an air –to-air missile, particularly those of the smaller variety that don’t use booster packs and the like.

This is all part of what is known as the BVR Paradox which, put simply, leads to the obvious conclusion that in any sort of engagement, you are always within visual range – whether it be within visual range of the aggressor IADS aircraft or SAM system or within visual range of their particular weapons when in flight. Just as in the classic WVR engagement wherein one of the objectives is to out manoeuvre you opponent’s aircraft to achieve the aim of a kill while avoiding being shot, so it is when being engaged by a missile. The longer the missile is in flight (as in what has been called the BVR situation), the more time the target aircraft has to set up the dodge and evade.

Basically, to rely upon such adages as ‘let the missiles do the turning’ and ‘with the JSF systems, manoeuvring is irrelevant’ is simply nonsense and will lead to high aircraft losses and JSF pilots losing their lives. Same goes for the Super Hornet, though at likely higher rates of attrition.

[vardhank]

Vardhan,

I couldn't understand what you meant by flaps which retract and provide greater area.

Imagine a sliding window... in stealth/regular mode, the window would only be slightly open, to shield the engines as much as possible from radar, and to minimise drag... in high-AoA mode, the window would open fully, to allow much more air to be sucked in. this can be used for takeoff/landing and WVR situations, where stealth is less relevant

Wild idea # 3 ... ports at different places at the front of the aircraft, which open up when required, with fans sucking in air and feeding it to the main engine... obviously these would be ancillaries and would draw some power away from the main engine, but it might give you even greater angles of attack.

(Gurus, please note, these are meant to be mad-professor ideas. If the monster starts lurching towards the village, don't blame me.)

On a separate note, I don't think manouevrability will ever be useless... it's like saying cars don't need steering because all the roads in the future will be straight.

[negi]

The kind of impression which most of the folks on aviation forums have about BVR borders on fantasy, if you would look at the history of AA combat and the list of longest registered BVR kills you would find that the longest registered kill was somewhere in the vicinity of 15-20km and this in a sanitized airspace with AWACS support. Even if one has detected and tracked a bogey a reliable IFF system needs to be in place before one can pull the trigger and this pretty much puts a constraint on the kind of range one can intercept a flying AC.

The folks on the F-35 bandwagon definitely went overboard on the 'Maneuverability' part specially when they claim that F-35 needn't go into a *MERGE*, the moment we talk about WVR combat it is assumed that the two ACs have established a visual contact or are within visual range , at this close a range and the speed at which today's fighters fly a typical duel will last for at most several minutes and unless one of the ACs suddenly spawns behind the other there is no way one would be able to avoid a *MERGE* , to clarify the moment pilots would establish visual contact they would try to get behind other's tail regardless of whatever mythical sensors their AC is equipped with and Maneuverability would play a key part in deciding the outcome of such a duel.

Obviously passive tracking capability of DAS would be useful outside of the WVR envelope(as within visual range there are no extra marks for ability to track in passive mode vs active LRF) or even while returning from strike missions as unlike other contemporary IRST/FLIR systems it does cover the rear hemisphere as well.

[Sumeet]

Thanks, Avaracharan and Austin.

Austin I agree that sometimes, people even the professional folks go overboard while emphasizing a useful novel technology as basis for elimination of some thing basic/fundamental [like maneuverability in this case]. Don't know what is the reason for their exuberance.

Anyways here is some more stuff:

Here is another paper from 2001 written by an Indian professor at University of Arizona, Tuscon and some guy from Raytheon Missile System.

A multiple model algorithm for passive ranging: And air-to-air missile guidance

Passive guidance schemes that employ measurement of relative bearing to the target via an angle-of-arrival mechanism (such as optical telescope or radar antenna) offer several strategic benefits but suffer from the unavailability of measurement of range or range-rate. Passive ranging, i.e., estimation of range information from available measurements, is fraught with many technical challenges, and particularly in an air-to-air missile guidance context is complicated by a stubborn observability problem. As a missile maneuvers for an optimal intercept solution, range and range-rate observability are degraded and, in the presence of measurement noise and target acceleration, become completely unobservable. Available schemes that typically employ extended Kalman filter solutions perform well against non-maneuvering targets but suffer estimation bias and divergence as intercept is approached. Interactive Multiple Model solutions promoted in prior works show promise in removing estimation bias due to target maneuver but have so far been restricted to active ranging problems. In this paper we shall present a novel Multiple Maneuver Model Filter (termed M3F in the following) that employs a suite of constant acceleration models in order to reliably estimate any target maneuver executed in the vertical as well as the horizontal plane. To quantitatively demonstrate the tracking performance of this filter, a set of benchmark tracking scenarios which present a broad range of problems relevant to passive ranging in an air-to-air missile context is also developed in this work. It should be emphasized that while several benchmark tracking problems in a surveillance radar context are recently developed, especially for testing the beam steering efficiency of a phased array system, these are not particularly useful for evaluating the performance of an air-to-air missile guidance scheme, and hence the benchmark scenarios developed in this work are of independent interest. Simulations of the M3F against the benchmark cases are also included to demonstrate the superior performance offered by the present algorithm in reducing estimation bias compared to existing techniques.

Deterministic Method to Assess Kalman Filter Passive Ranging Solution Reliability

Abstract—For decades, the defense business has been plagued by not having a reliable, deterministic method to know when the Kalman filter solution for passive ranging application is reliable for use by the fighter pilot. This has made it hard to accurately assess when the ranging solution can be used for situation awareness and weapons use. To date, we have used ad hoc rules-of-thumb to assess when we think the estimate of the Kalman filter standard deviation on range is reliable. A reliable algorithm has been developed at BAE Systems Electronics & Integrated Solutions that monitors the Kalman gain matrix elements – and a patent is pending. The “settling” of the gain matrix elements relates directly to when we can assess the time when the passive ranging solution is within the 10 percent-of-truth value. The focus of the paper is on surface-based passive ranging – but the method is applicable to airborne targets as well.

The author’s personal experience in developing passive, angle-only target tracking began at General Electric Company’s Aerospace & Electronic Systems Department (AESD) in Utica, New York in the late 1970s using the infrared search and track (IRST) sensor intensity and angle data on F-15 aircraft {Connect this with currently available passive ranging using IR}; electronic warfare sensors that provide RF parameters and angle data {Connect this with ALR-94 on F-22 and ALQ-218 jammer on EA Growler}; and cooperative aircraft anglebased tracking {connect this with KaranM's post of Bill Sweetman's article about multiple EFs using their PIRATE IRST to do Kinematic ranging/angling}. Stealthy operation was a principal driver. The Kalman filter was the basic algorithm building block – which we discuss in more detail in this paper.

I am trying to research and connect all dots. There are multitude of techniques out there to implement IR and RWR based passive ranging. Americans are ahead in this game. And I cannot but emphasize importance of this on a stealth aircraft. Hopefully our AMCA and FGFA have this incorporated in their sensors.

BAE Systems, LM and NG have mastered passive ranging technique enough that it can be packed into real and working systems and deployed on fighters in (near) future.

Another piece of information from Lockheed's Site:

IRST™ Sensor System Fire Control for the 21st Century

The high resolution characteristics of IRST provide dramatically improved raid cell count (40 times more accurate than radar) at maximum declaration ranges – information that can stand alone or be fused with other sensor data to enhance situational awareness, ensuring first-to-see, first-to-shoot capability.The IRST scan volume is comparable to radar, with selectable scan volumes in azimuth and elevation, and can operate in either track-while-scan or single-target-track modes. Additionally, IRST provides autonomous, passive range on targets to develop a weapon-quality solution, as well as track data to enhance target engagement.

IRST subsystems include: a sensor head with a three-axis inertially stabilized gimbal unit that scans the optics and detector assembly, a COTS processor that hosts the algorithms and a high density digital recorder. {Note: LRF is totally absent. You have entirely passive ranging by IR Sensor} IRST is compact enough to be mounted in various locations, from a conformal fuselage mount to a pylon. On the F/A-18E/F it will be mounted in the nose section of the centerline fuel tank. Lockheed Martin, The Boeing Company, and the U.S. Air Force are developing an IRST pod for the F-15C which will be transportable across a wide range of platforms.

[Sumeet]

Obviously passive tracking capability of DAS would be useful outside of the WVR envelope(as within visual range there are no extra marks for ability to track in passive mode vs active LRF) or even while returning from strike missions as unlike other contemporary IRST/FLIR systems it does cover the rear hemisphere as well.

Passive Ranging using RWR and IR sensor are very important for a true stealth aircraft. I hope we develop something similar for AMCA and FGFA.

[Avarachan]

Sumeet, you're welcome.

Austin, thanks for posting that email from Peter Goon at APA. I always thought that the "maneuvering is irrelevant" slogan was nonsense--it's good to get confirmation of that from a professional.

All of this gives me even greater respect for the Russian decision to balance RCS considerations along with the other traditional requirements of a fighter jet (speed, maneuverability, weapons payload, internal fuel capacity, maintainability, affordability, etc.). Making radical compromises on those traditional requirements for the sake of stealth is foolish.

[Gaur]

Sumeet,
From a quick look at your post, I am getting some idea regarding DAS's capabilities. When I get some time off, I will make sure to read your post in full. It should be very educational. So, thanks for researching so much info.

[SaiK]

How much of passive sensors could be used for homing? Perhaps it could be used in stealth mode at a reasonable BVR distance to keep a track for the possible next targets. It would be great to have a passive seeker.

Passive sensors triggering chaffs and flares are one aspect in WVR use (MAWS integration). If the missile sensor tech advances to differentiate between the signature of actual chaff and flare to that of locked signature, then seat ejection is the only answer.

[Cain Marko]

The capabilities of the DAS have been seen somewhat earlier via the Rafale - it is this approach targeting via passive sensors and using a BVR IIR weapon that makes the Rafale somewhat different in its approach to A2A. I believe the Rafale uses the OSF+Spectra to get ranging information. Supposedly good enough to engage at v.long distances (think meteor).

As far as 360* coverage goes, doesn't the MiG-35 attempt something similar with a downward facing OLS? Not 360 but still a rather large FOV. Although I don't believe the 35 has the kind of fusion required for effective ranging at bvr distances.

I expect such passive ranging capabilities to be standard issue on upcoming 5 gen a/c.

CM

[Kanson]

The kind of impression which most of the folks on aviation forums have about BVR borders on fantasy, if you would look at the history of AA combat and the list of longest registered BVR kills you would find that the longest registered kill was somewhere in the vicinity of 15-20km and this in a sanitized airspace with AWACS support. Even if one has detected and tracked a bogey a reliable IFF system needs to be in place before one can pull the trigger and this pretty much puts a constraint on the kind of range one can intercept a flying AC.

That is becoz of lack of understanding about the BVR concept.

Another way defining BVR missile is WVR or near BVR missle optimized for long range.
True range of BVR missiles is in WVR or near BVR(around 40 Km). True range of Astra missile is around 20 km. It changes with the altitude. Most likely we are only interested in talking about head-on ranges. Head-on range is a range achievable in extreme conditions. As the conditions are extreme, as extreme conditions don't happen regularly, probability of Kills achievable in extreme conditions at max range is very less. As the condition complicates, the ranges at which the kills happen reduces. As we talked about conditions influencing the kills at long ranges, with development of tech and better practices, chances of meeting these conditions are improving. That is the reason, people are still investing in BVR techs. Otherwise, we will be hearing more from Prof. Das and not about DAS.

Although they take things to extreme by making statements like "Maneuvering is Irrelevant".

I had asked this question to Peter Goon from APA and he had replied to me , below is his the reply

wrt your proposition – “. . . coz a HOBS missile can always outmanouvere the target.”

Not so. Do the math and you will see it does not take much manoeuvring on the part of even an agile target to evade/dodge, say, the AIM-120 – even the kinematic/aerodynamic capabilities of the AIM-120D. Extreme agility just makes this a whole lot easier, and that’s all before you consider the effects of EW ECM, etc.

Firing from a HOBS position only makes it harder for the missile. Every turn the missile has to make reduces the somewhat finite energy able to be incorporated into an air –to-air missile, particularly those of the smaller variety that don’t use booster packs and the like.

This is all part of what is known as the BVR Paradox which, put simply, leads to the obvious conclusion that in any sort of engagement, you are always within visual range – whether it be within visual range of the aggressor IADS aircraft or SAM system or within visual range of their particular weapons when in flight. Just as in the classic WVR engagement wherein one of the objectives is to out manoeuvre you opponent’s aircraft to achieve the aim of a kill while avoiding being shot, so it is when being engaged by a missile. The longer the missile is in flight (as in what has been called the BVR situation), the more time the target aircraft has to set up the dodge and evade.

Basically, to rely upon such adages as ‘let the missiles do the turning’ and ‘with the JSF systems, manoeuvring is irrelevant’ is simply nonsense and will lead to high aircraft losses and JSF pilots losing their lives. Same goes for the Super Hornet, though at likely higher rates of attrition.

Nice to know from APA/Peter Goon. But it has been that APA is known for its induced bias against F-35.

wrt your proposition – “. . . coz a HOBS missile can always outmanouvere the target.”

Not so. Do the math and you will see it does not take much manoeuvring on the part of even an agile target to evade/dodge, say, the AIM-120 – even the kinematic/aerodynamic capabilities of the AIM-120D. Extreme agility just makes this a whole lot easier, and that’s all before you consider the effects of EW ECM, etc.

Firing from a HOBS position only makes it harder for the missile. Every turn the missile has to make reduces the somewhat finite energy able to be incorporated into an air –to-air missile, particularly those of the smaller variety that don’t use booster packs and the like.

HOBS missile *can* out manoeuvre the target if the target is within its kill box. Kill box of such missile is greater than the kill box of missile which is not having HOBS. Becoz of HOBS properties, missiles kinematics profile is chosen to compensate for the loss and missile is designed accordingly. Modern newly built missiles are energy aware.

He is right about manoeuvering target evading/dodging missile. It happens more often with BVR than WVR if situation favours aircraft.

If this discussion is WRT to DAS & HOBS missile, it is clearly mentioned in NG promo video shown firing HOBS missile using DAS that either it makes the approaching aircraft to break off from chasing the F-35 or face the consequences. So i think no one claims HOBS missile means it out manoeuvres the target.

In the scenario depicted by the NG promo video clip, though the missile takes a 180 deg turn, it position itself for a head-on engagement with the approaching target a/c. That is the most favourable position either to kill the mission or the aircraft. In that sense one can claim, "manoeuvring is irrelevant".

This is all part of what is known as the BVR Paradox which, put simply, leads to the obvious conclusion that in any sort of engagement, you are always within visual range – whether it be within visual range of the aggressor IADS aircraft or SAM system or within visual range of their particular weapons when in flight. Just as in the classic WVR engagement wherein one of the objectives is to out manoeuvre you opponent’s aircraft to achieve the aim of a kill while avoiding being shot, so it is when being engaged by a missile. The longer the missile is in flight (as in what has been called the BVR situation), the more time the target aircraft has to set up the dodge and evade.

I think, he has given an answer for the 4th gen system than for the 5th gen system. Anti-missile laser may be part of F-35. F-35 can avoid threats. It is fast enough to respond to any developing threats and can carry missiles like AIM-120D and Meteor. I couldn't agree with him on BVR Paradox wrt F-35.

Sumeet, nice explanatory post. I guess, you must be knowing about Raytheon ADAS for helis. It is also talks about sound triangulation and sound approach warning system(?).

[Sumeet]

Gaur,

Take your time.

Kanson,

Thanks. I am aware of ADAS, have glanced through its features. But no detail knowledge of this system.

Cain Marko,

The reason I didn't mention Rafale is:

Thales technologies onboard the Rafale

Thales’s Front-Sector Optronics (FSO) system is fully integrated into the Rafale to provide covert long-range detection and identification, high-resolution angular tracking and laser range-finding for air, sea and ground targets. Operating in optical avelengths, this sensor is immune to radar jamming.

So Rafale, EF and even MKI don't quite fit in with the context of our current discussion which centers around total passive searching, detection, tracking and calculating target data [both bearing and range (without LRF)].

Althought Rafale, EF and MKI do a lot of this passively, they have to depend on LRF for range data. We are talking about true 5th generation sensor system that truly befits a true 5th generation fighter.

[Austin]

Some nice piece of information on PAK-FA ( via flateric/otaku )

Multimode highly-integrated aerodynamic Aircraft Layout

[Indranil]

^^^ Austin ... thanks for that ... I have always wondered what's with the broad neck of the PakFA behind the cockpit. This paper explained it.

Also it specifies the "side cargo compartments 7". Co that triangular tube like structure by the side of the air intakes is a bay tucked up into the wing! Lot's of people had speculated over it in the first few pages of this thread. It is a simple weapons bay and that's great

P.S. If you put figure 5 and the the Plan view of the Pak-FA together from here, it becomes quite clear that the PakFa doesn't have the serpentine air intakes. They would be using some other kind of radar blocker. I am aware of the radar blockers that posters have posted here. Are there any specifics available?

[srai]

Thanks, Avaracharan and Austin.

Austin I agree that sometimes, people even the professional folks go overboard while emphasizing a useful novel technology as basis for elimination of some thing basic/fundamental [like maneuverability in this case]. Don't know what is the reason for their exuberance.

...

It's simple really. If you build a product (in this case a JSF with not that great maneuverability) and you want to sell that product, your sales and marketing team has to come up with some novel sales pitch and fancy marketing brochures, "coin" catchy phrases (i.e. "Maneuvering is Irrelevant"), and recruit (paid/unpaid) "brand" ambassadors (former pilots/generals) and evangelists (aka fanboys/journalists) to spread the word until it becomes an accepted norm.

[Austin]

P.S. If you put figure 5 and the the Plan view of the Pak-FA together from here, it becomes quite clear that the PakFa doesn't have the serpentine air intakes. They would be using some other kind of radar blocker. I am aware of the radar blockers that posters have posted here. Are there any specifics available?

Its difficult to say the Plan 5 is just a generic picture and not the kind where you can make a valid argument if the engine and intake are in straight line ( i.e. Flanker ) . Every pak-fa picture should there is a tilt in the intake and engine angle not a straight line for sure.

Its certainly not the classic serpentine or S intake , so a blocker/ram is a certain.

[b_patel]

Thanks to Otaku from Key pubs. This is the OFFICIAL patent for PAK-FA. I really hope the diagrams for the ducts are wrong b/c this might finally prove that PAK-FA doesn't have serpentine intakes. Hopefully the radar blocker they are working on works as well as they hope, otherwise they are in big trouble.

12) ABSTRACT OF INVENTION
Status: As of 08.11.2010 - is valid

(21), (22) Application: 2009133611/11, 09.09.2009

(24) Date of the origin of the term of the patent:
09.09.2009

(46) Published: 09/27/2010

(72) Author (s):
Mikhail Pogosyan Aslanovich (RU),
Davidenko Aleksandr Nikolaevich (RU),
Strelets Mikhail (RU),
Runishev Vladimir Aleksandrovich (RU),
Tarasov Alexey Z. (RU)

(73) patent (s):
Open Joint Stock Company "Sukhoi" (RU)

(54) MULTIMODE highly-integrated aerodynamic AIRCRAFT LAYOUT

(57) Abstract:
The aircraft has a fuselage, in which the middle part (2) seamlessly paired with swept wing (3), warhead (1) and tail (6), where the all-moving vertical tail (4) and all-moving horizontal tail (5). The head part (1) the fuselage is light (10). The fuselage has increased the width of the cross section and recruited from airfoils whose height allows you to place the main cargo compartment in the fuselage between the air intakes. The invention is directed to a uniform distribution of air loads and increase load-bearing properties of the fuselage. 10 ill.


Спойлер: Скрыть
The invention relates to multi-mode aircraft operated in supersonic and subsonic flight speeds in a wide range of altitudes. Preferred scope of the invention are multi-mode super-maneuverable aircraft with a cruising flight at supersonic speeds and low level of visibility in the radar (radar) range.

Known in the art aircraft integral aerodynamic layout containing one carrying the fuselage, in which the middle part of the fuselage smoothly paired with swept wing, head of the fuselage and its tail part (RU 2140376 C1).

As a well-known shortcomings of the aircraft should indicate the following. In a plane distribution of goods to the external load does not allow to achieve a low degree of visibility of the radar, and high aerodynamic characteristics at supersonic flight regimes.

Due to the complex technical solutions applied in the layout and, above all, the integrated aerodynamic configuration of the fuselage, the plane is characterized by high value of the aerodynamic qualities at subsonic flight conditions.

The technical result on the aim of the invention is to create an aircraft has a low level of radar visibility, maneuverability at high angles of attack, high aerodynamic efficiency at supersonic speeds and at the same time preserving a high aerodynamic quality at subsonic regimes.

The technical result is achieved by a multi-mode highly maneuverable aircraft integral aerodynamic layout containing the fuselage, the middle part of which is smoothly conjugate with swept wing, head of the fuselage and tail, all-moving vertical and all-moving horizontal tail located in the rear fuselage, the average integrated with the fuselage center-wing and made flattened in the vertical direction, and its outer surface in the longitudinal direction is formed by a set of airfoils with high building heights, providing accommodation within the fuselage, built-in cargo compartments, with the upper surface of the fuselage, paired with the outer surface of the lamp and the expanding at the site from the lantern to the tail section of fuselage with decreasing curvature.

The invention is illustrated by drawings, where Figure 1 shows the plane in plan view, in Figure 2 - section A-A Figure 1; in Figure 3 - section B-B Figure 1; in Figure 4 - section B In Figure 2, in Figure 5 - section F-F Figure 2, Figure 6 - Rotation of least resistance (the body Siirsa-Haack) on Figure 7 - position of transverse sections of fuselage in Figure 8 - transverse section 7 shows, in Figure 9 - Schedule of cross-sections of the aircraft fuselage; Figure 10 - The enlarged part of the graphic cross-sectional areas of the fuselage of a lantern.

The aircraft has a fuselage, in which the average of the two seamlessly paired with swept wing 3, the head part 1 of the fuselage and the tail 6. In the rear part 6 of the fuselage are all-moving vertical 4 and all-moving horizontal tail 5. At the head of a fuselage is light 10.

In terms of aerodynamic layout aircraft has the following features: wide lifting fuselage and smoothed graph cross-sectional areas at the site of an airplane cockpit.

The fuselage has increased the width of the cross section (Fig. 1, 2) and recruited from the airfoils 11, 12, 13 (Figure 3, 4, 5), whose height can accommodate the main cargo compartment 9 in the fuselage of the aircraft (Figure 2, 3) between the air inlets 8 and also provides the necessary building height to accommodate the side cargo compartments 7 (Figure 2, 4).

In addition to space for cargo, resulting in a flattened layout an even distribution of air loads on airframe surface and an increase in load-bearing properties of the fuselage from the perspective of a lifting force that allows you to keep the aerodynamic characteristics of aircraft in general, smaller wing area,

In addition, a flattening of the fuselage reduces the effective area of the radar in the most likely areas of exposure: Side and front projection plane.

Smoothing schedule cross-sectional areas at the site of an airplane cockpit can improve the aerodynamic characteristics of aircraft by reducing drag.

Besides the general theoretical outline, the aerodynamics of the plane and drag affect the arrangement and mutual linkage aircraft parts. To estimate the drag on the mutual influence (interference), the design rule is used areas (Figure 6), which is as follows: in order to reduce the resistance, curve 14 cross-sectional areas of all elements of Sj plane along the length of the aircraft shall comply with the diagrams of the equivalent body of revolution least resistance (cigar-shaped body of high aspect ratio, the so-called body Siirsa-Haack).

According to the state of the art in the design of aircraft used the scheme to link canopy and fuselage, shown in Figure 8 (A - a common scheme), which is characterized by the fact that cross-sectional area decreases in the area of the canopy to the tail. The schedule of areas for this scheme has a marked departure from the body Siirsa-Haack in the canopy (Figure 9 and Figure 10, section A).

To improve the aerodynamic characteristics of a scheme for linking, which consists in the fact that the upper surface 15 of the fuselage expands on the section of the lamp 10 to the rear part 6 of the fuselage, compensating for the decrease in cross sectional area (Figure 8, B - invented by the scheme), resulting in smoother "failure "on the graph area of a lamp driver, which is characteristic for conventional aircraft integral aerodynamic layout. The curve on the chart area close to the optimal shape, which indicates an improvement in aerodynamic performance (Figure 10, section by reducing drag.


Claim
Multimode highly maneuverable aircraft integral aerodynamic layout containing the fuselage, the middle part of which is smoothly conjugate with swept wing, head of the fuselage and tail, all-moving vertical and all-moving horizontal tail located in the rear fuselage, wherein the middle part of the fuselage is integrated with center-wing and made flattened in the vertical direction, and its outer surface in the longitudinal direction is formed by a set of airfoils with high building heights, providing accommodation within the fuselage built cargo compartments, with the upper surface of the fuselage, paired with the outer surface of the lamp and extending the area from the lantern to the tail section of fuselage with decreasing curvature.
__________________

[SaiK]

http://ablogin.ru/wp-content/gallery/av ... pg.jpg.jpg

Is there a S shaped depth to the inlet on the dorsal-ventral axis? I think there is no S yet, perhaps planned for FGFA versions, by squeezing the inlet opening to come closer or spread apart that much to make the bent. Or, it could be a vertical axis bent.. bottom line, very much possible modifications for FGFA.

[Cain Marko]

Thanks to Otaku from Key pubs. This is the OFFICIAL patent for PAK-FA. I really hope the diagrams for the ducts are wrong b/c this might finally prove that PAK-FA doesn't have serpentine intakes. Hopefully the radar blocker they are working on works as well as they hope, otherwise they are in big trouble.

Why exactly are they in big trouble? And how does this prove that the a/c does not have curvature from inlet to engine compressor face?

CM

[Sancho]

Althought Rafale, EF and MKI do a lot of this passively, they have to depend on LRF for range data. We are talking about true 5th generation sensor system that truly befits a true 5th generation fighter.

Hi Sumeet, I think you are mistaken about the capabilities of Rafale and SPECTRA as well as the lead of the US in this field.

What you basically said is, that the F35 uses it's EWS combined with ETOS to passively detect, track and identify targets, as well as engage them. But that is something that the Rafale F3 already can and the F3+ offered in MMRCA will do even better.
Of course you are right that radar and laser signals can be detected, but the laser range-finder, that you pointed out for FSO is not directly linked to the IRST. Unlike MKI with OLS, or the EF with PIRATE, the Rafale has not only an IRST, but combines different sensors in FSO as you can see here:



On the left we see the IRST sensor of Rafale which is fully passive, on the right instead we see the TV channel of the FSO, which is used for identification of the targets and includes also the laser range-finder. Here is the Thales brochure of FSO, where this is also shown at TECHNICAL CHARACTERISTICS, the laser range-finder is an addition to the identification channel and not combined with the IRST:

http://www.thalesgroup.com/assets/0/93/ ... gType=2057


Just like you pointed out for the US systems in F22, or F35, SPECTRA can use several sensors for passive detecting, tracking and identifying of targets, in the air as well on the ground. The RWR can detect radars up to 200Km ranges, twice the range that is quoted for the EF so far, besides several other sensors like its IIR MAWS that already provides 360° detection and all combined offers spherical SA to the pilot similar to what F35.
Rafale is not a stealth fighter of course, but be it in BVR combats, or in penetrating enemy air space during strike missions, these capabilities are big advantages and they are even pratically proven during exercises like Red Flag, NATO MACE, or ATLC. Here are some quotes of various reports about it:

The Rafale also can rely on several other sensors:

Front-Sector Optronics (or OSF for optronique secteur frontal) system, developed by Thales (for TV) and Sagem (IR). Integrated over the aircraft’s nose in the form of a double ball, it can operate in the optronic wavelengths and provide long-distance tracking in the full passive mode. It is immune to radar jamming and provides covert long-range detection and identification, high resolution angular tracking and laser range-finding for air, sea and ground targets.
Spectra EW system, developed by Thales and MBDA, provides a multi-spectral threat warning capability against hostile radars, missiles and lasers. According to test pilots who have flown the Rafale, the EW system provides the aircraft with the highest survivability assets against airborne and ground threats to date. It also provides passive, 360-degree tactical situation awareness.

Considered a fully automatic self-protection system, Spectra provides passive, all-weather reliable, long-range detection, identification and geographical location of threats in the infrared, electromagnectic and electro-optical ranges. It uses short response times and cutting-edge defensive measures based on a combination of jamming, decoying and evasive maneuvers and technologies, such as Digital Radio Frequency Memory (DRFM) for signal processing.

The efficiency of Spectra notably was demonstrated in 2008 at the Red Flag exercise at Nellis Air Force Base, Nevada, where during all sorties the Rafale escaped SAM missile threats. This followed a successful demonstration at the NATO MACE electronic warfare campaign in Europe.

The angular localization performance of Spectra makes it possible to precisely discover ground threats and to target them for immediate destruction with precision-guided munitions. In this totally passive mode, Spectra is also used as a general awareness and intelligence reporting system.

http://www.aviationtoday.com/av/categor ... 32315.html

One of the more challenging aspects of Rafale operations is how to fully exploit its capabilities, and especially its range of passive sensors. Pilots, for example, can use its TV/thermal imaging observation system (dubbed Optronique Secteur Frontal, and similar in principle to infrared scan and track) to visually identify other aircraft at ranges of more than 50 kilometres (approx. 30 nautical miles), and transmit this and other tactical data to other aircraft using their MIDS datalink.

Another unique capability, according to Col. François Moussez, the French Air force’s Rafale program officer is that it can fire missiles at targets detected and designated by its integrated Spectra countermeasures suite, again without any need for active transmissions that can give away its position.

http://forum.keypublishing.co.uk/showpo ... tcount=578

ATLC [...] Better yet, december 7, a pair of Rafale which protected a SAR combat device shot down 10 incoming hostile fighters while dropping six AASM on 6 different land targets forty km far, everything without leaving their CAP racetrack.
On 6 December, a MICA has been assigned its target - indeed virtually destroyed - only with the SPECTRA system. SPECTRA which was also capable, twice, to detect and classify - and to propose flight path changes to the pilot to avoid detection-specific envelope - some air defense systems (SA-6) that even the F-16 CJ American specialized in the SEAD mission (suppression of air defense opponents), yet also in flight, were not able to collect

DSI magazine may 2010


The Rafale F3+, that is offered in MMRCA will also have the DDM NG MAWS, which is an improved version of the present system, that provides also IR imaging like ETOS:
http://www.deagel.com/news/DDM-NG-Deliv ... 07243.aspx



As you can see Rafale with FSO and SPECTRA fulfills your requirements of an 5. gen system like the F35 will have too and adds additional sensors like the laser range-finder, or the AESA radar too. Just like Cain Marko said, the French made a different approach, by not focusing on the AESA radar mainly, but investing much more into the EWS and passive detection capabilities. That makes Rafale way different than any MMRCA contender and much closer to 5. gen fighters like the F35!

SPECTRA and it's passive capabilities are one reason why I hope that Indian forces will choose Rafale! With the long range AESA radars and air superiority capabilities of MKI and FGFA in future, Rafale would complement them perfectly and would offer a highly capable combo for air defense and strikes.
If we can get ToT of SPECTRA through Rafale procurement it would be great for FGFA too.
Stealth, 360° passive detection, possibly 360° AESA radar detection (still not sure about that), SC, TVC, high maneuverability - what a great fighter!


Regards, Sancho

[Viv S]

What you basically said is, that the F35 uses it's EWS combined with ETOS to passively detect, track and identify targets, as well as engage them. But that is something that the Rafale F3 already can and the F3+ offered in MMRCA will do even better.
Of course you are right that radar and laser signals can be detected, but the laser range-finder, that you pointed out for FSO is not directly linked to the IRST. Unlike MKI with OLS, or the EF with PIRATE, the Rafale has not only an IRST, but combines different sensors in FSO as you can see here:

On the left we see the IRST sensor of Rafale which is fully passive, on the right instead we see the TV channel of the FSO, which is used for identification of the targets and includes also the laser range-finder. Here is the Thales brochure of FSO, where this is also shown at TECHNICAL CHARACTERISTICS, the laser range-finder is an addition to the identification channel and not combined with the IRST:

Just like you pointed out for the US systems in F22, or F35, SPECTRA can use several sensors for passive detecting, tracking and identifying of targets, in the air as well on the ground. The RWR can detect radars up to 200Km ranges, twice the range that is quoted for the EF so far, besides several other sensors like its IIR MAWS that already provides 360° detection and all combined offers spherical SA to the pilot similar to what F35.

Hi there Sancho I was wondering if I'd see you around. - Vnomad

With regard to your post,

Exactly which sensor does the Rafale field, that the EF/SH/MiG-35 don't? The IRST, TV guidance, MAWS, LWR, TRD are all featured on the EF. And the DASS does provide 360° protection. Also, the PIRATE can be used for passive kills just like the SPECTRA.

Also, with regard to the Rafale's RWR range being twice that of EF, what are we taking as a benchmark? A ground or AWACS based pulse doppler may up at a very long range while an fighter sized AESA may not show up until its close to visual range. Until we've got all the figures at hand I don't think we can make any conclusions based on open sources figures without any clarification from the original source.