British weapons for the F-35

F-35 Armament, fuel tanks, internal and external hardpoints, loadouts, and other stores.
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by timmymagic » 24 Sep 2020, 16:05

marauder2048 wrote:When has US defense export policy ever been motivated by market share considerations?


That segment has never really come under pressure, particularly with traditional buyers of US gear like SK and Japan. No-one likes to see market dominance lost or reduced.

timmymagic wrote:Meteor is going to give the RN a hell of a CAP capability (in most ways it would be superior to the old F-14/Phoenix combination).


7-inch diameter seeker and 50 lb warhead vs a 15-inch diamater seeker + 150 lb warhead?[/quote]

Well Meteor works for one (although to be fair we're presuming that)...longer ranged, more manoeverable at the end game, radar will be more effective at long range as well.


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by mixelflick » 24 Sep 2020, 16:28

No question F-35B/Meteor trumps the F-14/Phoenix, but that's of course expected.

Think about it though... how advanced was the Phoenix, that we're talking about it even now? The F-14/AWG-9 plus Phoenix pairing was downright fearsome, as experience in Iranian service showed. There was nothing remotely close to its capabilities when originally fielded, and even today it represents a credible threat (Iranian F-14AM's plus Fakhour 90). It would be a mistake to take that combo lightly, and provided their F-14's really have been updated with new radars, E/W suite etc... represents a credible threat to just about everything flying (minus the F-22 and F-35).

It's a whole lotta' missile, moving incredibly fast with a monster warhead. Not something I'd want to be confronted with, that's for sure..


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by marauder2048 » 24 Sep 2020, 16:30

timmymagic wrote:
marauder2048 wrote:When has US defense export policy ever been motivated by market share considerations?


That segment has never really come under pressure, particularly with traditional buyers of US gear like SK and Japan. No-one likes to see market dominance lost or reduced.


I've yet to see evidence that concerns about market dominance or lack thereof influences US defense export policy.


timmymagic wrote:
Well Meteor works for one (although to be fair we're presuming that)...longer ranged, more manoeverable at the end game, radar will be more effective at long range as well.


There's really no evidence for any of this.


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by marauder2048 » 24 Sep 2020, 16:34

sprstdlyscottsmn wrote:
marauder2048 wrote:
timmymagic wrote:Meteor is going to give the RN a hell of a CAP capability (in most ways it would be superior to the old F-14/Phoenix combination).


7-inch diameter seeker and 50 lb warhead vs a 15-inch diamater seeker + 150 lb warhead?


that 7-in seeker is going to be far more capable. Improved Tx/Rx losses, signal processing software, etc. And really it is the kinematics that are being discussed here. Meteor range is rather unparalleled with a throttleable ramrocket.


Given that seeker perf is cubic in aperture...
Not sure where you get improved Tx/RX losses. It's not an AESA.
I don't see any evidence that the 7-inch VFDR beats the 15-inch SRM when lofted for range.


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by sprstdlyscottsmn » 24 Sep 2020, 16:38

marauder2048 wrote:
Given that seeker perf is cubic in aperture....


While not inaccurate, it is far from the whole picture when it comes to radar. I've given my reasons for my thoughts, you have given yours. We disagree about the end result. No biggie.
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by marauder2048 » 24 Sep 2020, 16:58

sprstdlyscottsmn wrote:
While not inaccurate, it is far from the whole picture when it comes to radar


Sorry but unless there's an AESA in the mix Big-Oh analysis says that aperture is the whole picture.
Particularly when there's such a huge difference.


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by timmymagic » 24 Sep 2020, 17:46

marauder2048 wrote:There's really no evidence for any of this.


That Meteor is not more manoeuverable in the end game??

It's powered all the way, AIM-54 was coasting...there's no way its not going to have an enormous advantage at the point of intercept at range.


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by sprstdlyscottsmn » 24 Sep 2020, 17:57

marauder2048 wrote:
Sorry but unless there's an AESA in the mix Big-Oh analysis says that aperture is the whole picture.
Particularly when there's such a huge difference.


I don't know "Big-Oh" analysis, but I know that aperture is meaningless without wavelength, as the aperture relative to wavelength gives beam width and gain. So you can use a 2x frequency on a 1/2diameter aperture to get the same beamwidth. I know that SW in the back end can be used to determine returns from lower S:N ratios. I know that both hardware design and heating of the system can effect the receiving gain to a large degree. I know that output wattage is not solely a factor of aperture. Even old MSA radars are a lot more than just aperture.

In the end we don't have anywhere near all the numbers to plug in to get the answer. So in looking back at my statement I should have said it could be better, not that it is better.
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by marauder2048 » 24 Sep 2020, 18:01

timmymagic wrote:
marauder2048 wrote:There's really no evidence for any of this.


That Meteor is not more manoeuverable in the end game??

It's powered all the way, AIM-54 was coasting...there's no way its not going to have an enormous advantage at the point of intercept at range.


It's not clear that the higher Vbo for AIm-54C in a loft loses to the ducted rocket. And if there is an increase
in miss distance it's not clear that's not compensated for by the much larger warhead.


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by marauder2048 » 24 Sep 2020, 18:19

sprstdlyscottsmn wrote:
marauder2048 wrote:
Sorry but unless there's an AESA in the mix Big-Oh analysis says that aperture is the whole picture.
Particularly when there's such a huge difference.


I don't know "Big-Oh" analysis, but I know that aperture is meaningless without wavelength, as the aperture relative to wavelength gives beam width and gain. So you can use a 2x frequency on a 1/2diameter aperture to get the same beamwidth. I know that SW in the back end can be used to determine returns from lower S:N ratios. I know that both hardware design and heating of the system can effect the receiving gain to a large degree. I know that output wattage is not solely a factor of aperture. Even old MSA radars are a lot more than just aperture.


Big-Oh says that a cubic term dominates all other terms of a lesser power. Everything else you've mentioned
is a linear term. And of course a higher frequency has greater propagation losses.

And, IIRC, we are talking about the same frequency for AIM-54 and Meteor.


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by timmymagic » 24 Sep 2020, 19:32

squirrelshoes wrote:
timmymagic wrote:SpearGlide

First time I've heard of this.

Sounds like SDB2ish?


Pretty much that. At DSEi 2019 MBDA and the UK MoD talked about 'spiral developments' of Spear, Brimstone tech and other UK IP. One of those was Spear-EW, which is the Spear missile combined with Leonardo's Britecloud DRFM jammer technology. The US equivalent would be MALD-J/N/X. That got a development contract. Another mentioned development was SpearGlide, which was also seen at Paris. Basically, its a direct competitor for SBD2 Stormbreaker. It's the same form factor as Spear, same sensors and overall weight balance. The jet and fuel are removed and replaced with a larger warhead though. To all intents and purposes it will match SBD2 exactly. Should be a very easy development and should also be incredibly easy to integrate to any platform that has had Spear integrated.

They also talked around other 'spiral developments' to Spear, to create a 'family' of munitions. Nothing mentioned but the size of Spear, the desire for a family of weapons, MBDA's existing portfolio and the competition could point us to some possibilities, just speculation...but some obvious ones below:

1) - SDB1 equivalent - This is the obvious one. A 'SpearSimple' if you like. No expensive sensors just GPS and SAL, gliding only with the ability to penetrate a hard target. Has to be dirt cheap.
2) - SpearRecon - An attritable drone with a cheap E/O sensor for a look 'over the hill' with data transmitted back to launch platform. Could be useful for BDA. Could lead to the below..
3) - E/O seeker head - Could provide extreme accuracy for low collateral strikes at range, like the Israeli Delilah. Comparatively cheap as well.
4) - Loitering version - Switching the jet for a more fuel efficient internal combustion engine and prop could create a useful, cheap air launched loitering munition. The issue of control and seeker for it would need to be addressed though, simple and cheap with offboard control or more autonomous and expensive. Could be a simple 'spiral' with a Recon version and an E/O seeker head. Lots of attempts at this sort of concept before, but in truth the idea sometimes seems better than the reality.
5) - Air-to-Air - I've seen this posited before, an air to air version to hunt UAV's and rotary wing. Could be cheaper than a 'normal' A2A missile for more vulnerable targets, but its a bit of a niche capability. The idea some have had of it hunting in an area seems a little far-fetched for the type of seeker it could usefully carry.

Apart from that I can't think of any more, the size of the form factor and limit on power generation capability counts out some of the more novel payloads, and there comes a point where the juice isn't worth the squeeze.


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by sprstdlyscottsmn » 24 Sep 2020, 19:36

marauder2048 wrote:
Big-Oh says that a cubic term dominates all other terms of a lesser power. Everything else you've mentioned
is a linear term. And of course a higher frequency has greater propagation losses.

And, IIRC, we are talking about the same frequency for AIM-54 and Meteor.


Hmm, I think I need a bit more help here. I am seeing effective Aperture as being the same as Gain, or Power, or S:N. all are 4th root wrt Range, none are cubic. I know the radar equation has many derivations so I am wondering which one you are looking at.

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by marauder2048 » 24 Sep 2020, 20:59

sprstdlyscottsmn wrote:Hmm, I think I need a bit more help here. I am seeing effective Aperture as being the same as Gain, or Power, or S:N. all are 4th root wrt Range, none are cubic. I know the radar equation has many derivations so I am wondering which one you are looking at.


We commonly call the center figure PAG since those "variables" in are in fact inderdependent.
If you increase the aperture you increase the gain by virtue of a smaller beam size.
You also tend to have more radiated and received power (in the monostatic case). Because of the independency
of that term we say that increases in aperture result in cubic increases.

It's why everyone tries to build bigger radars (see SM-6); the other figures are much harder to manipulate in a way that produces big increases. In fact, aperture size is about the only meaningful thing they changed on SM-6 relative to AIM-120.

There are practical limitations like weight and drag for A2A missiles so you end up with a compromise.


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by sprstdlyscottsmn » 24 Sep 2020, 21:09

marauder2048 wrote: We commonly call the center figure PAG since they are inderdependent.
If you increase the aperture you increase the gain by virtue of a smaller beam size.
You also tend to have more radiated and received power (in the monostatic case). Because of the independency
of that term we say that increases in aperture result in cubic increases.

I see, thank you. So, yes, all other things constant, aperture is cubic. I doubt any of the rest is actually constant myself, but I see how it would be an uphill battle. Even doubling the frequency (and yes you already covered the propagation issue) will just hold G constant while A gets slashed, and newer hardware allowing you to thermally push the same power through a smaller antenna still keeps P constant. The only place to make it up would be improved S:N processing, but half the diameter means A is cut to a quarter so improving S:N by 4x is unlikely. At best you are mitigating your losses unless you have a PESA or AESA.

Thanks for taking the time to more thoroughly explain your position.
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by marauder2048 » 25 Sep 2020, 01:00

sprstdlyscottsmn wrote:
Thanks for taking the time to more thoroughly explain your position.


No problem. And I don't mean to imply that it's not worth every bit of effort expended on improving
processing and other gains (e.g. pulse compression/coherent integration) and reducing noise.
AESAs are all about the latter and as you see the gains can be quadratic on monostatic since Tx/Rx
noise tends to be reduced by the same factor.

Every bit helps and if you move enough linear terms in the right direction everything is better.
But the big hammer is aperture.

The later versions of AIM-54C seeker were digital and had very good processing gains so it's not
immediately clear to me that a half-aperture seeker other than an AESA could move enough
terms in the right direction to compensate.


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