Is there any recent news about Pakistan missile H-4?

Crobato:

But this is the key difference and where the beauty of datalink + ARH missile comes in. The secure nature of the datalink makes this kind of sneaky attack a real threat. Who is launching it and how you launch it does matter.

Unlike what you said in #59, this is an advantage that SARH doesn’t have.

SARH missiles also have datalinks.

The final terminal attack phase of the ARH missile will not use the datalink. It will use its onboard illuminator and therefore warns the target’s RWR when it does. You cannot have a complete datalink control of the missile’s flight right to the end.

If you want to talk about typical situation, then pilots sometimes have to engage 2~4 aircrafts at the same time. In that case ARH is still superior.

Its easier to do it with ARH, but it’s not impossible with SARH. Ships and SAMs have been doing as much as 10 targets with a single illuminator.

In group situation, the head-on fighter would also have the opportunity to shoot BVR and break, then allow undetected friendly fighter to get into a better position for WVR.

Why would you do that? The head on fighter if he’s not being attacked, can get straight on for the kill.

Heck, if I want to scare the other guy, I’ll lit up his RWR with my radar using STT mode without firing any missile. He would think I did and therefore tries to evade, putting him in a situation with my close range attack.

The point is, ARH allows the flexibility. In military having the flexibility is always good, no matter what.

Of course. But my point remains is that SARH is still a very dead option, deadlier than most people think it is.

Mind you, Vortex, that article I pointed to you about, seems much more actual based in my experience both in China and Japan. You need to see this with your own eyes.

Crobato:
No I am definitely not talking about TWS mode. I said without Track-while-scan.

What you’re describing is track while scan. The AMRAAM only fires using TWS or STT in BVR, or in any of the dogfighting modes (like boresight) which is besides the point. HOJ (hot on jam) is firing blindly without knowing who the actual target is.

AIM-120 has been tested using datalink in the so-called silent attacks. Gripen’s TIDLS is one example of these kind of applications – only one Gripen needs to do radar sweeps, while several others could use it for attacks. I am pretty sure US military also tested this with JTIDS as well. Using SARH missiles, you have to illuminate in the final phase, which gives enemy fighter time to react (no matter how short).

Wrong.

You cannot use datalink alone in the terminal phase. Datalink do not have the CEP or the precision to bring you within proximity range of warhead explosion. AIM-120 still requires illumination (from onboard the missile) in the terminal phase.

I’m pretty sure in those cases, the missiles still light up the moment they reached terminal stage.

What do you mean by passing SARH command to another platform?

Same thing like you described above, which is missile hand over. You say AAM isn’t LGB, but LGB does work on a semiactive principle, using laser instead of radar. The operating principles remain the same for the two.

AAM isn’t LGB, I’ve never heard of such things. Besides, how does this make a difference? Passing illumination still requires illumination by another aircraft, it doesn’t make your missile attack undetectable like the datalink silent attack.

No difference in terms of warning time since both missiles need to light up at the terminal stage.

OK, I guess the only part I really disagree is this:
-You said that SARH + INS is almost as good as ARH. Supposedly the main difference is the terminal guidance and that’s a very short time and distance, therefore it doesn’t matter that much.

If you have the type of datalink similar to Gripen, then you could guide ARH without using TWS. This effectively gives you an ability to do a silent attack. While the enemy might know that he is being track by one opposing fighter, he doesn’t know another fighter has launched a missile against him. This is not a common used because this kind of datalink attack is hard, but it’s an advantage nevertheless.

You’re talking about track while scan mode.

No it’s not that big an advantage because SARH with datalinked INS can do just about the same thing. With SARH, you can have a target lit up by one illuminator in the final phase. and missiles from different launchng platforms all headed to it. SARH can also be fire and forget if you can pass over command of the missile to another platform, who can also take over illumination duties.

Both AMRAAM and AIM-7M/P can be launched from TWS mode.

In single fighter fight if both fighters launched missiles, the side with ARH has more flexibility and could switch mode and launch more missiles or break and depoly countermeasures. The side with SARH has to finish illuminating first. This type of scenario is similar to multi-target engagement.

You only illuminate in the final phase of missile flight. That’s how you do it. In theory, an F-15 for example, could ripple launch AIM-7M on different targets while on TWS mode, each target designated at TWS. The illuminators only go on towards the final phase of flight.

Life and Death in modern air combat are often decided in few seconds, I don’t think it’s correct to say that SARH’s limitation in terminal phase isn’t important.

Yes, I think it’s a disadvantage.

As for SARH having advantage in ECM environments, well that’s assuming your radar is strong enough. A lot of these advantages/disadvantages are dependent on pre-defined conditions. This is more related to specific systems rather than SARH vs ARH in general.

SARH illuminators, based on the launching platform are much more likely to be much more powerful than the small portable battery powered illuminators missiles have.

I also do not think your description of ARH AAM fits all the different types of AAM out there today. Take AIM-120 as example, it has two modes: radar targeting with datalink or autonomous (option of using radar or without using radar). The AIM-120 flies with IN system, then at the range of seeker, the seeker goes active and switch to home-on-jamming. Now, to increase accuracy or if enemy already knows he’s being fired upon, the radar could do a mid-course update to correct missile flight path. This is obviously different from the nature of SARH missiles.

Well what you don’t seem to know is that SARH missiles can also have INS with update link. If the ARH missile is fired autonomously, it’s usually fired relatively close to the target, which heavily negates range advantage. If you desire to fire an ARH missile at any significant range, you would have to use it with the update datalink. In that sense, an ARH and a SARH missile has no difference, until you get to the seeker’s range.

SARH+INS update like AIM-7M/P do not require direct illumination in the midphase of flight. Illumination is only required in the terminal phase. That is how SAM solutions can engage multiple targets at once with only one or relatively few illuminators. SARH that requires direct illumination from the missile’s launch belongs to an earlier generation of SARH missiles (AIM-7F).

SARH solutions are used before because electronics were relatively crude then. Using an illuminator in the missile takes up space for the propellant, warhead and seeker electronics. That’s why the first real ARH missiles like the Phoenix were quite huge, and ARH was used mainly in AshMs as even these missiles on the average are relatively huge compared to AAMs. To counter the relatively weak illuminator in the missile, you also need very sensitive receivers as well.

There is no doubt that ARH solutions are more flexible, except in the case of low RCS targets and heavy ECM environments, where stationary SARH illuminators will burn through these problems by sheer brute force. It is that SARH solutions still remain potent today and despite the marketing lingo ARH missiles are not true fire and forget when it comes to ranged attacks, not unless you can develop an illuminator around 20cm in diameter that can successfully illuminate a target up to 60 to 70km away, or meet that halfway with a generation of even more sensitive receivers.

Crob,
I think you’ve got me convinced on the FC-1. I originally was of the same line of thought re this aircraft, but whent the FTC-2000 emerged, i got puzzled because i still had the S-7 in the back of my mind. The idea crawled upon me that the FTC-2000 was more of a halfway development variant between the J-7 and the FC-1 as per the original S-7 program, but as you say the FC-1’s design is definately an original (and hence indigenous) one.

I think Grumman was involved in the original S-7 not in the plane design, but in the avionics systems. The nose graft J-7 job seems much more like a Chinese idea to me than American in the fair tradition of the Q-5 Fantan. There are more than enough dreamy engineers at that time in China to provide a more than adequate supply of concept planes.

CWI is used when you depend on a directional receiver. Doppler devices are needed if you don’t want to simply ignore signals from one direction. These are the two main ways to deal with the problem of differentiating echo from source.

Continuous wave is the more simpler of the two. Both AMRAAM and Phoenix from what I read are able to emit and receive pulse doppler radiation. In fact the AMRAAM was supposed to take ADVANTAGE of the new doppler radars coming out in the late 1980s and 1990s. The AWG-9 of the F-15 is a pulse doppler.

I’m sorry but I have to keep telling you that AMRAAM and Phoenix are all monopulse seekers. Missiles like these get their range information via datalink from the parent plane. Once they’re in terminal range and the seeker goes on, they’re just homing towards the target via monopulse reciever, which gives directional information only.

For the Sparrow, the AIM-7F added the ability to receive pulse doppler and expanded the range all the way out to 76 miles.

No, it’s also a monopulse.

No one said it was the same. But calculating the doppler shift has been been used since the first modern proximity fuses in US artillery shells in WWII The AIM-9 proximity fusing system is an IR but it uses the same principle. You can’t measure distance between objects where there is at least one moving without calculating the doppler shift.

The IR proximity fuse doesn’t stick out a ruler and measure distance to target before exploding. It tracks light bouncing back from the target, measures it (usually between two separater receivers) and figures out closing speed before exploding.

Now, the only proximity fuse that doesn’t require calculating the doppler shift is a magnetic fuse on a torpedo. It is set off by the magnetic field around the target.

No. BVRAAMs do not use doppler shift for proximity fusing. Why would they? The same system used in IR systems is much simpler and easier. If your proximity fusing is not linked to your radar, the fusing cannot be defeated by countermeasures.

Nope, this is the argument. The difference between having the illuminator aboard and the illuminator elsewhere on another device is very different.

Wrong again. Does not matter much for monopulse recievers.

All missiles do. If not for guidance then for proximity fusing. Again, the more advance missiles: AMRAAM, AIM-7F and the AIM-54 also have provisions for it for guidance.

Again, I’m not arguing the CWI is not used. It is used when you attempt to guide without bothering to differentiate echo from source.

No no no. Radar homing missiles do not use pulse doppler.

It didn’t because the radar is still king.

The early F-14 had IRSTs. It was then and it is now, a good complement to the main show, the radar. But it nothing more than a complement. The IRSTs on the Fulcrums and Flankers that people feared never because the main show. They would still need to turn on their radars.

So?

Okay, say it does work well over range. It doesn’t work well from the frontal aspect, so where does it leave us? 🙂

Rear and side aspects are also important.

Nope, it was only partially solved 20 yrears ago when the AIM-9L all aspect came about and it’s still only partially solved today. IR is much more accurate within range. It’s probably has an extremely high kill percentage within in the 2.6 miles range that the first AIM-9 operated.

But the problems of different aspect, longer range and weather related externals are not solved and is still an ongoing process. Otherwise, we would freeze the AIM-9M design.

No no no. The problem of more intense heat souces was already solved even before the AIM-9L came. By the time you have all aspect missiles, the ability for IR seekers to discriminate heat sources was become clever enough that decoy and flare design has become an artform.

Differentiation is a problem that occurs the further you are away from the target. Back in the past it, was a problem even when you had tone (or lock.) The problem is “solved” for the range we used in the past.

No no no. Differentiation is quite easy—regardless of distance. That is because the spectra of the sun’s heat, the spectra of a burning building, and the spectra of a jet engine exhaust are all different. The heat spectra of each heat source has its own unique signature. You simply design and program your IR seeker to look for this signature.

Differentiating between the target over extended range is currently better with radar energy than heat. And it will probably always be so.

It’s true but it does not eliminate IR for BVR use. With heat sources giving out exponentially greater radiant energy than reflected signals, the signal for IR would be far stronger and positive than radar. You can get better range using techiques of contrast—a warm object against a very cold background like the sky will show nicely.

Granted, the IR is a good complement.

Anyways, a device can only tell if a target is receding by calculating doppler shift 🙂

Range for receding targets would indeed drop of radically. If a radar has a 100km range head on lock on, on a tail aspect your lock on range is down to 30km. In IR, if the seeker only has a 10km seeker range from the front, on the rear, it can go as far as 50 to 60km from the tail.