Operational Performance Comparison: Viper, Beagle and Stubby

[ricnunes]

If OSF laser range finder system is equally powerful as ATFLIR, it can start launching Meteor toward F-35 from 74 km.

Really, this again?!

Well for the "million-time-ish":
- There's no way an IRST will detect a fighter aircraft at those ranges (74km or more) operationally and this even against a 4th/4.5th gen fighter aircraft.
As mentioned by marsavian above the F-35 (as well as the F-22) also have extensive IR reduction measures (much more extensive than any 4th/4.5th fighter aircraft) which means that IRST definitely won't detect aircraft like the F-35 at such long ranges.
Sure the IRST could have advantages over the Radar when the stealth/F-35 aircraft is at closer ranges (let's say below 20km) but at longer ranges it will be as "blind" as a radar!
Then, I also don't think that any Laser Rangefinder fitted in any IRST will have a 74km range.

Finally, think this way: If IRST's where that good as advertised than why would fighter aircraft carry radars at all??
All of them would carry IRST's only instead. Lighter aircraft plus Passive-detection with equal or even better performance than Radar, what would be better than this right? But no, this isn't what really happens.

Also, for the "million time" please stop devising some scenarios where a 4.5th could have an advantage over a 5th gen F-35. There simply aren't!
Just like in the past, everytime that a new fighter aircraft technology and generation comes up it smacks the previous fighter aircraft technology and generation and this won't be any different now!
Now of course you can think whatever you want but it seems to me that you're putting "faith" ahead of "facts". My 2 cents really...

[swiss]

Maybe. The Meteor may be at a higher elevation (colder background, more contrast). Co-altitude, sure.

This sounds likely . But i assume the IRST has to look directly to the incoming missiles to detect it. And it seems modern BVR missiles comes mostly from above.

Su-30 body can hide the engine plumes, for a missile, it is impossible, and ramjet plume is hotter than jet engine plume, at great height, missile contrail can be detected from remarkable distance. At the same time, Meteor can't be out run

Why is a ramjet plume hotter than a jet plume? I assume also depends if the jet engine is in mill power or afterburner.

In a clear sky sure. But the question is how many miles away. After the rocket booster burns out i assume the contrail depends on weather conditions. According to Bayern-Chemie the Meteor has a reduced smoke propellant (Boron) .

[eloise]

Well for the "million-time-ish":
- There's no way an IRST will detect a fighter aircraft at those ranges (74km or more) operationally and this even against a 4th/4.5th gen fighter aircraft.

EOTS can identify hotel window from 49 nm (90 km) and it isn't some system with ultra large aperture. In thatcase the FoV is very narrow but it can be cued with ESM system
viewtopic.php?f=22&t=27945

Then, I also don't think that any Laser Rangefinder fitted in any IRST will have a 74km range.

ATFLIR is a common targeting pod in the same generation as Sniper-XR
Sniper-XR was repackaged inside F-35. At least F-35 IRST can have that kind of powerful LRF.
it is unfair to conclude whether others IRST system got powerful LRF or not without knowing their real size

Finally, think this way: If IRST's where that good as advertised than why would fighter aircraft carry radars at all?? .

Because radar max range vs high value target is longer
They are not affect by weather
Radar can track targets at the same time
Radar are versatile for many roles

[sprstdlyscottsmn]

ATFLIR is a common targeting pod in the same generation as Sniper-XR

ATFLIR is a generation beyond Sniper-XR AFAIK.

[eloise]

ATFLIR is a generation beyond Sniper-XR AFAIK.

They were made around the same time
ATFLIR was used by USN
SNiper-XR was used by USAF

[wrightwing]

APG-81 detection range vs Rafale
If Rafale RCS is 0.1 m2. There is 50% chance it is detected from 155 km and 90% chance it is detected from 96 km.
If OSF laser range finder system is equally powerful as ATFLIR, it can start launching Meteor toward F-35 from 74 km.
I assume F-35 cruise speed is Mach 0.85, Rafale supercruise speed is Mach 1.2 => closure rate is Mach 2.05
At 45.000 feet altitude, speed of sound is 1062 km/h, so F-35 has between 36 - 133 seconds to engage Rafale before Rafale can return fire.

Radar.PNG

But with Spectra, Rafale can reduce APG-81 detection distance, it is possible that they will attack one another at the same time so i propose another tactic
1- F-35 cruising at 45.000 feet, immediately launch 2 AIM-120D at Rafale once APG-81 find it. Rafale counterattack by launching several Meteor with guidance from OFS.
2- Right after launching 2 AIM-120D, F-35 should dive below 20.000 ft to hide within the cloud layer, OFS can't track F-35 through clouds so midcourse guidance to Meteor will be disrupted. By contrast, F-35 can keep provide mid-course guidance by APG-81
3-F-35 launch support jammer such as SPEAR-EW/MALD-J to neutralize RBE-2
4-Launch 2 meteors from below cloud layer. Ramjet missiles are more suitable for low altitude launch.


Load out: 2 AIM-120D/2 meteor/4 SPEAR-EW /2 AIM-132

1- a Rafale with missiles and fuel tanks is going to have an RCS over 1m^2.
2- OSF isn't going to detect (much less track) an F-35 at 74km.
3- F-35s cruise closer to M.95 (and up to M1.2 without afterburners.)
4- the F-35 can launch AIM-120Ds outside of the Rafale's radar/IRST range.

[eloise]

1- a Rafale with missiles and fuel tanks is going to have an RCS over 1m^2.
2- OSF isn't going to detect (much less track) an F-35 at 74km.
3- F-35s cruise closer to M.95 (and up to M1.2 without afterburners.)
4- the F-35 can launch AIM-120Ds outside of the Rafale's radar/IRST range.

1- It can fly without fuel tank or drop fuel tank once ESM indicate there are enemies in the area

2- We don't know how good the new OSF is, Talios pod should be as good as ATFLIR , Sniper-XR.
3- Faster = more heat = easier to detect
4- However, can APG-81under jamming tracks Rafale before Talios/OFS get a track on F-35?

[optimist]

This is where I lost interest on the last page, Even the rafale guys must have trouble. To keep up the 'I do believe in fairies' this much. I hate seeing fairies die, like they did on the Gripen thread.

APG-81 detection range vs Rafale
If Rafale RCS is 0.1 m2.

[marsavian]

With a flat AESA antenna facing back 90 degrees to the world 0.1 sq m seems quite unlikely. However Eloise's general point is valid, as radar is denied range due to stealth and ECM, electro-optics do become relatively more important in detecting and tracking, it's just simple physics. Because the F-35 needed a ground laser attack system that was not overlooked in its design and it will keep pace with its competition.

[eloise]

Pirate is a dedicated IRST, considered the gold standard right now.

Legion pod is the best IRST at the moment, look at that aperture area

[spazsinbad]

Looks like the second pic cannot be hotlinked so it is attached below: http://aviationintel.com/wp-content/upl ... _1200w.jpg It is unnecessarily large so the pic is HALVED for this forum....

[wrightwing]

1- It can fly without fuel tank or drop fuel tank once ESM indicate there are enemies in the area

Not very far, and it's unlikely that the tanks will be dropped before AMRAAMs are on the way

4- However, can APG-81under jamming tracks Rafale before Talios/OFS get a track on F-35?

Very likely. The Rafale has to detect the APG-81 before it can attempt to jam it. By that point, it won't be able to jam the EOTS or ASQ-239, much less 3rd party targeting (Or dealing with the F-35's jamming.)

[ricnunes]

EOTS can identify hotel window from 49 nm (90 km) and it isn't some system with ultra large aperture. In thatcase the FoV is very narrow but it can be cued with ESM system
viewtopic.php?f=22&t=27945

First you're confusing IRST with an EO sensor such as the Sniper (which the EOTS and its EO functions are based on) or ATFLR or Damocles or Talios or whatever.
For example the EOTS (as well as other modern EO sensors/pods) uses very high performance MWIR sensors which allows you to look at targets thru an IR imagery which has a resolution very close to what the human eye sees (light spectrum).

Basically the principle of using the EOTS to find very long range targets like shown in the video above is like using a "normal" telescope and speaking of which good luck trying to find aircraft flying around the airspace simply by looking at a telescope which otherwise in theory allows you to look at the same aircraft at very long ranges (which requires to have something that helps cueing the telescope - more on that below).

Regarding the IRST the principle is the same/similar but the sensors that most if not all IRSTs use aren't the very high performance MWIR sensors as you find on an EOTS (or on other EO sensor/pods such as ATFLIR, etc...) - they are from lower quality which should hamper detection and above all, identification range.

Moreover you're conveniently forgetting that the F-35 has in-build IR reductions measures which will drastically degrade the maximum detection range that an IRST could theoretically have against a F-35.

So and getting back to the video above, how do you think that the pilot found the windows of that building/hotel in Las Vegas with the EOTS in the first place??
- I believe that I can reply it: First it had to find the building (that contain the windows) itself, something which by itself is massively bigger and STATIC compared to a F-35! So and even before that building could have been found by the EOTS, the EOTS was (and I'm 99.99% sure of this) cued by something else in order to point the EOTS on the vicinity.
Since this was from a F-35, it was definitely thru a track feed by the sensor fusion (as you can see in a bunch of F-35 videos!) and the biggest contributors to that same track could have either been the Radar (yes, the R-A-D-A-R) and/or a pre-determined area/waypoint.

What do I mean with the above? Good luck trying to find that same building (not to mention its windows!!) using the EOTS alone...

Because radar max range vs high value target is longer
They are not affect by weather
Radar can track targets at the same time
Radar are versatile for many roles

So, here you are!
So can you please stop now with these "magical scenarios" where a Rafale could detect a F-35 first or about the same time at BVR range as opposed to otherwise? Thanks in advance...

1- It can fly without fuel tank or drop fuel tank once ESM indicate there are enemies in the area

External tanks will only be dropped in emergency situations! No External tank will be dropped lightly or just to get a somehow lower RCS - They are too expensive for that!
And then even after dropping the external fuel tanks you'll still have the pylons to "contend to" which will still contribute to increase the RCS somehow.

4- However, can APG-81under jamming tracks Rafale before Talios/OFS get a track on F-35?

For the "million times" (I guess):
- YES, YES and YES!

Again don't forget that the F-35 in-built IR-Reduction measures will "jam" (hamper/limit are the accurate terms here, obviously - "jam" term is just an "analogy") the Rafale's OSF (or any other IRST carried by any other aircraft).

[optimist]

When you drop an external tank. They say you light up like a xmas tree on radar. Would they have resolved the fuel vapour issue yet?

[spazsinbad]

When you drop an external tank. They say you light up like a xmas tree on radar. Would they have resolved the fuel vapour issue yet?

Where does the fuel vapour come from? How much fuel and for how long? I'll guess one would have to know what happens when a fuel tank is dropped (empty/part full/full) on any aircraft - as a general rule. Then probably it is - not much?