Finnish DefMin Interest in F-35s NOT Gripens

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bear21

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Unread post27 Jul 2020, 20:53

f119doctor wrote:
bear21 wrote:The other comment around this specific simulation is its values for the rear hemisphere is lower than the other simulations, as no rear of an F35 engine is simulated (it has the same problems as the front of an engine but no S-ducts or RAM to conceal the items like burner flame holders and last turbine blades). RCS values are, therefore, with a high probability higher than shown here, which is a hard surface simulation of a flat surface engine outlet.


Bad assumption about the F135 engine RCS, both inlet and exhaust. Sorry, can’t be any more specific than that.


I make no assumptions about the F35 inlet. Why do you assume that? I do say that the outlet is straight and has no RAM (the jet outlet, I don't talk about the nozzle or area around the nozzle). Now you tell me how you have RAM in a jet engine turbine nozzle and afterbuner that can attain >1000°C.
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bear21

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Unread post27 Jul 2020, 21:01

ricnunes wrote:
f119doctor wrote:
bear21 wrote:The other comment around this specific simulation is its values for the rear hemisphere is lower than the other simulations, as no rear of an F35 engine is simulated (it has the same problems as the front of an engine but no S-ducts or RAM to conceal the items like burner flame holders and last turbine blades). RCS values are, therefore, with a high probability higher than shown here, which is a hard surface simulation of a flat surface engine outlet.


Bad assumption about the F135 engine RCS, both inlet and exhaust. Sorry, can’t be any more specific than that.


Yup, bad assumption up there and bad assumption down below:

f119doctor wrote:The values are in line with the widely quoted RCS for the F35 of 0.01m2 RCS in the front 120° sector


(The F-35 RCS is 'widely reported' to be lower than 0.001 square meters, much lower than 0.01 square meter above)

More awful assumptions below:
f119doctor wrote:In summary, the F35 has a strange EW system, extremely strong where it’s not needed and virtually absent where it’s needed.


The 'author above' forgets that for instance that the APG-81 radar acts like an EW antenna and that due to its lower RCS the F-35 can get closer much to the radar source and (attack) jam it far more effectively than for instance a Gripen with that EW pod in development will ever be able to do.

The 'author above' also completely forgets that even if a enemy radar system manages to somehow detect a F-35 at a useful range (doesn't matter at which angle the aircraft is facing the enemy radar, etc...) that the same enemy radar system will manage to detect any 4.5th/non-stealth fighter aircraft at much, much, much and much higher (a huge magnitude higher) distance/range than it will ever be able to detect the F-35.

Ultimately, the 'author above' forgets that only recently the F-35 entered in service and will receive lots and lots of upgrades during its lifetime including to its EW system.
Posters like the above seem for some odd reason to believe that only 4.5th gen fighter aircraft are 'illegible' to receive massive upgrades but for some reason the F-35 can not :roll:

Resuming, another typical post of some occasional "new people" coming here trying to prove the ridiculous point that aircraft like the Gripen (or any other 4.5th gen) may have a minimal change against a F-35 or better than the F-35 in performing the intended roles for fighter aircraft.
The post above is IMO ever more 'ridiculous' since the author is trying very hard to prove that other aircraft have a better chance against advanced Air Defence System like the S-400 :roll: :doh:

And now, here we go again... :roll:


Re the RCS. OK, so lower the values with another factor 10. It doesn't change the reasoning.

And what I can read there is nothing in the post about 4 gen fighters. The post is about the strange design of the F35 EW system. I didn't comment on any other aircraft or EW system, 4th gen or 5th gen.
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f119doctor

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Unread post27 Jul 2020, 21:47

bear21 wrote:
f119doctor wrote:
bear21 wrote:The other comment around this specific simulation is its values for the rear hemisphere is lower than the other simulations, as no rear of an F35 engine is simulated (it has the same problems as the front of an engine but no S-ducts or RAM to conceal the items like burner flame holders and last turbine blades). RCS values are, therefore, with a high probability higher than shown here, which is a hard surface simulation of a flat surface engine outlet.


Bad assumption about the F135 engine RCS, both inlet and exhaust. Sorry, can’t be any more specific than that.


I make no assumptions about the F35 inlet. Why do you assume that? I do say that the outlet is straight and has no RAM (the jet outlet, I don't talk about the nozzle or area around the nozzle). Now you tell me how you have RAM in a jet engine turbine nozzle and afterbuner that can attain >1000°C.


Inlet - OK, you didn't make any assumptions about the RCS of the inlet. But there is more to Inlet RCS than S-ducts and RAM coatings.

Exhaust - Yes, the F135 has internal and external component shaping, positioning, and cooling to address both RCS and IR signature. And again yes, there are high temperature exhaust system coatings (and advanced component design to help keep those coatings intact) that are intended to last an overhaul interval in the afterburner environment of the engine. P&W has some of the world's best material scientists, engineers, and processes to make this happen.
P&W FSR (retired) - TF30 / F100 /F119 /F135
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jessmo112

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Unread post27 Jul 2020, 23:38

it's been revealed that the F-35 has a lower RCS than the F-22. ... from the rear because engineers reduced cost by not designing a radar blocker for the engine exhaust." ... Their design eliminates conventional spray bars and flame holders and integrates ...

From a simple search.
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wrightwing

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Unread post27 Jul 2020, 23:51

Pro-tip: there isn't any angle, where an F-35 isn't many orders of magnitude stealthier, than any 4th generation jet. It has 360° spherical signature reduction. It also as a signature management system, which not only alerts pilots to all hostile emitters, but the ranges where detection becomes possible. As for EW, the ASQ-239 provides spherical coverage, along with the APG-81s electronic attack/jamming, and towed decoys that also have jammers. If all of that fails, there's always smart expendables to break RF/IR lock. In Block 4 you can add MSDM to the mix, which allows F-35s to shoot down incoming missiles, and later in the decade, you can also add DEW/DIRCM to the mix.
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optimist

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Unread post28 Jul 2020, 14:35

Bear, it's going to be hard to get an RCS of a flame holder, when the F-35 doesn't even have one. I don't think any more needs to be said about what you think.
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ricnunes

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Unread post28 Jul 2020, 14:38

bear21 wrote:Re the RCS. OK, so lower the values with another factor 10. It doesn't change the reasoning.


There is much more to this than a simple lowering of a RCS value by a factor of 10.
For instance a radar that can detect an aircraft with a RCS of 0.01 square meters at a maximum range of 151 km will only be able to detect an aircraft with a RCS of 0.001 square meters at a maximum range of 85 km or putting into another perspective, the detection range is reduced by almost half! This is HUGE!

And like jessmo112 said, the F-35 is even stealthier compared to the F-22 which means that the F-35 RCS figure is actually lower than the 0.001 square meter value mentioned above.


bear21 wrote:And what I can read there is nothing in the post about 4 gen fighters. The post is about the strange design of the F35 EW system. I didn't comment on any other aircraft or EW system, 4th gen or 5th gen.


Ok, I probably got you wrong here.

I'm probably excusing myself but since there are some some (many?) new posters coming here with all sorts of 'rants' claiming that 'X' aircraft is better than the F-35 and that 'Y aircraft' is better than the F-35, etc, etc... and this by using the most ridiculous conclusions (and even 'propaganda') means that I seemed to have jumped to a conclusion. Also and IMO, posting in this thread (Finnish DefMin Interest in F-35s NOT Gripens) probably didn't help.
Anyway, if this is the case then I apologize.
“Active stealth” is what the ignorant nay sayers call ECM and pretend like it’s new.
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magitsu

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Unread post28 Jul 2020, 18:54

These occasionally tend to include a bit of tunnel vision. For the purpose of this thread we shouldn't be talking quite as much about a single unit of specific fighter, when we know that the standard operation is a flight of 4. Which is completely different when accounting for things like the possibility of cooperative EW.
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bear21

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Unread post28 Jul 2020, 20:26

magitsu wrote:These occasionally tend to include a bit of tunnel vision. For the purpose of this thread we shouldn't be talking quite as much about a single unit of specific fighter, when we know that the standard operation is a flight of 4. Which is completely different when accounting for things like the possibility of cooperative EW.


I agree. Cooperative EW via a realtime link like MADL is interesting and powerful. In this case, I fail to see how it solves the coverage problem of the jammer. Enlighten me.
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Unread post28 Jul 2020, 22:04

bear21 wrote:I agree. Cooperative EW via a realtime link like MADL is interesting and powerful. In this case, I fail to see how it solves the coverage problem of the jammer. Enlighten me.


F-35's EW system covers more than previous gen platforms. It's more effective to hide what's already a VLO platform than legacy with similar jammer energy.
It's not necessary or even feasible to try to disrupt everything, just select pieces of the kill chain. For example X band alone covers most fighter radars and missile radar seeker heads... and it already has capability for the next few high bands.

NGJ or whatever is needed to beef up F-35's EW capability in the future will cover more ground. Because the F-35 user base is the biggest business opportunity around for the next few decades.

It's probably more healthy to look it from the perspective of an overall improvement instead of demanding the best solution in every regard. Growler is likely still very useful, but F-35s are much more capable of doing things of their own that we are used to. The overall perspective seems to be changing with the F-35. For example Typhoon is probably an air superiority fighter (owning the air), but the F-35's forte seems to be information superiority (quarterbacking the battlespace).
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Unread post29 Jul 2020, 06:31

bear21 wrote:
The F35 has four towed decoys to tow behind the jet, but these work as beacons and reveal the jets to any tracking radars. For a BVR A-A case, they work well as you can adapt the geometry and the missile is very limited in its miss distance lethality.

Image

For a front or rear S400 case there is a major geometrical problem as the proximity fuse of the missile will not trigger on the decoy and the miss distance to the F35 can be close enough to make it lethal (this problem is why towed decoys are seeding to Britecloud type free fly decoys in several newer systems).


AFAIK, they have far more capabilities than being just beacons. For example AN/ALE-55: https://www.baesystems.com/en/product/a ... owed-decoy

Unlike traditional decoys, such as straight-through repeaters, the fiber-optic towed decoy works synergistically with an aircraft’s onboard electronic warfare equipment to defeat radio frequency threats. It protects aircraft throughout the threat envelope, delivering three layers of defense.


and https://www.baesystems.com/en/download- ... 725027.pdf

The AN/ALE-55 subsystem consists of an on-board signal conditioning assembly and the FOTD. The signal conditioning assembly converts RF frequencies to light for transfer through the fiber-optic line. The system has two modes. In the primary mode, the onboard EW system detects and analyzes a threat, determines the appropriate response, and then sends that response down the line to the FOTD for transmission. The alternative back-up mode is an independent repeater. In this mode, the threat signal is detected, modulated, and then sent down the line to the FOTD. The system can interface with any on-board techniques generator, and can convert any technique. This broad capability enables the system to be installed on a variety of aircraft and to handle both today’s range of techniques and any developed to defeat future threats.


About AN/ALE-70:
https://www.militaryaerospace.com/unman ... ys-for-f35

When deployed from the aircraft, the ALE-70’s countermeasure transmitter responds to commands from the countermeasure controller located in the jet and emits waveforms to confuse or decoy adversary radars or radar-guided weapons. The system may be towed or free-flying.


The low RCS of F-35 directly helps the EW system as there is much smaller signature to conceal. So it can protect against much more powerful radars or from a lot closer distances than similar systems used in 4th gen fighters.
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ricnunes

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Unread post29 Jul 2020, 15:07

bear21 wrote:I agree. Cooperative EW via a realtime link like MADL is interesting and powerful. In this case, I fail to see how it solves the coverage problem of the jammer. Enlighten me.


In the following thread/link you can read a nice discussion about the topic:
viewtopic.php?f=62&t=56869

In that thread/link you can read a source where it points out that the F-22's EW system (RWR/ESM part) with band 3 and 4 antennas can cover as low as the 0.5 GHz frequency. You can also read that the F-16 AN/ASQ-213 (an older system) can cover as low as 0.5 GHz.
So I'm pretty sure that the F-35 EW system which is basically a much improved F-22 EW system and together with band 2 antennas that the RWR/ESM part of the F-35 EW system can cover much lower frequencies than 0.5 GHz (which goes well within the VHF band for instance) and thus contradicts what you said in a previous post of yours (which I'll re-post below):
• The RWR/ESM part has coverage 2-6GHz (Band 3), 6-18GHz (Band 4) as a base and adds 05-2Ghz (Band 2) and 18-40Ghz (Band 5) for Block 4. LM etc. only say Band 3, 4, and so on but you don't have to be Einstein to put in the GHz values.


Resuming, this is well in line with what magitsu said in his last post: the F-35's EW system covers more than previous gen platforms.
“Active stealth” is what the ignorant nay sayers call ECM and pretend like it’s new.
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Unread post30 Jul 2020, 04:27

hornetfinn wrote:
bear21 wrote:
The F35 has four towed decoys to tow behind the jet, but these work as beacons and reveal the jets to any tracking radars. For a BVR A-A case, they work well as you can adapt the geometry and the missile is very limited in its miss distance lethality.

Image

For a front or rear S400 case there is a major geometrical problem as the proximity fuse of the missile will not trigger on the decoy and the miss distance to the F35 can be close enough to make it lethal (this problem is why towed decoys are seeding to Britecloud type free fly decoys in several newer systems).


AFAIK, they have far more capabilities than being just beacons. For example AN/ALE-55: https://www.baesystems.com/en/product/a ... owed-decoy

Unlike traditional decoys, such as straight-through repeaters, the fiber-optic towed decoy works synergistically with an aircraft’s onboard electronic warfare equipment to defeat radio frequency threats. It protects aircraft throughout the threat envelope, delivering three layers of defense.


and https://www.baesystems.com/en/download- ... 725027.pdf

The AN/ALE-55 subsystem consists of an on-board signal conditioning assembly and the FOTD. The signal conditioning assembly converts RF frequencies to light for transfer through the fiber-optic line. The system has two modes. In the primary mode, the onboard EW system detects and analyzes a threat, determines the appropriate response, and then sends that response down the line to the FOTD for transmission. The alternative back-up mode is an independent repeater. In this mode, the threat signal is detected, modulated, and then sent down the line to the FOTD. The system can interface with any on-board techniques generator, and can convert any technique. This broad capability enables the system to be installed on a variety of aircraft and to handle both today’s range of techniques and any developed to defeat future threats.


About AN/ALE-70:
https://www.militaryaerospace.com/unman ... ys-for-f35

When deployed from the aircraft, the ALE-70’s countermeasure transmitter responds to commands from the countermeasure controller located in the jet and emits waveforms to confuse or decoy adversary radars or radar-guided weapons. The system may be towed or free-flying.


The low RCS of F-35 directly helps the EW system as there is much smaller signature to conceal. So it can protect against much more powerful radars or from a lot closer distances than similar systems used in 4th gen fighters.


Thanks hornetfinn.

When I write they work as beacon I don't mean the first generation of towed decoys that weren't connected to the motherships EW system (those were simple repeaters and could be ECCM filtered as such). I meant that you have a very low RCS aircraft, where the main asset is the signal to noise ratio for any acquisition/tracking system being lousy. Now you start a transmitter hanging at X m behind this low observable platform that give those systems a perfect presence signal with a very good signal to noise ratio, whatever your ECM waveform.

The ERP of the decoys, dumb or intelligent like the ALE-55/70, is about a Watt of RF power times 0 dB gain (circular polarized broadband spiral fore and aft), i.e. about 1W ERP. This limits you smart ECM waveforms as the angle confusing waveforms against monopuls radars requires a high ERP/multiple apertures.

The main BVR missile in the Russian Air Force, the AA-10, is an angle tracker. As you try to fiddle with it's velocity gate you only improve it's angle tracking, and if sussefull (you don't know as it's a receive only system) you risk it switches to HOJ. Thus, the safe waveform is the decoy waveform to generate a miss distance to the F35.

For the SAM systems you give them a perfect track vector in angle as you apply range/velocity gate confusing waveforms. As the ALE-70 is the only omindirectional jammer for the F35, these intelligent and adaptable system can add X m forward to this vector and they have a perfect track of the F35.

Through the MADL you can apply cooperative ALE-70 jamming to get the desired angle deception, but now you need to place the formation in the same threat system angle and range cell.

For all cases you increase the threat system signal to noise ratio during your jamming and given the ERP, your choise of smart jamming waveforms are limited. If you cut the optical link and let the ALE-70 free fly, you have a non-smart transmitter from the cut moment.
Last edited by bear21 on 30 Jul 2020, 10:05, edited 1 time in total.
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Unread post30 Jul 2020, 04:43

ricnunes wrote:
bear21 wrote:I agree. Cooperative EW via a realtime link like MADL is interesting and powerful. In this case, I fail to see how it solves the coverage problem of the jammer. Enlighten me.


In the following thread/link you can read a nice discussion about the topic:
viewtopic.php?f=62&t=56869

In that thread/link you can read a source where it points out that the F-22's EW system (RWR/ESM part) with band 3 and 4 antennas can cover as low as the 0.5 GHz frequency. You can also read that the F-16 AN/ASQ-213 (an older system) can cover as low as 0.5 GHz.
So I'm pretty sure that the F-35 EW system which is basically a much improved F-22 EW system and together with band 2 antennas that the RWR/ESM part of the F-35 EW system can cover much lower frequencies than 0.5 GHz (which goes well within the VHF band for instance) and thus contradicts what you said in a previous post of yours (which I'll re-post below):
• The RWR/ESM part has coverage 2-6GHz (Band 3), 6-18GHz (Band 4) as a base and adds 05-2Ghz (Band 2) and 18-40Ghz (Band 5) for Block 4. LM etc. only say Band 3, 4, and so on but you don't have to be Einstein to put in the GHz values.


Resuming, this is well in line with what magitsu said in his last post: the F-35's EW system covers more than previous gen platforms.


I read the thread. It's some good scouted graphs of the F22 and some confustion in the interpretations. Here is why I think so:

The Figure 2.33 CNI and 2.34 EW tells the story. The confusion comes from not realizing that the low bands, 0, 1 and 2 covers from below100 Mhz to 2GHz and these frequencies are a mix of lots of stuff. Most is CNI like Radio systems, Nav systems, Data links, but also long range radar systems and command links for SAMs.

Look at the Band 2 antenna of 2.33 and compare with the Band 2 of the F35. Same type and placement, adjacent to the Band 3 and 4 antennas in both cases. I suggest the bands are the same in both cases and Band 3 is not covering to 0.5 Ghz. What is then Band 0, 1 and 2?
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Unread post30 Jul 2020, 05:36

This is so significantly deviating from the thread topic you really ought to have made your own thread.
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