R77 & AIM120 "MAGIC" FOV's ???

[Force_Feedback]

And in case you haven't noticed, some of us actually realize that the issue is for all ARHs and not just the 120. Is there any reason at ALL why you can't resist the urge to speak in a derogatory manner instead of injecting something constructive? Haven't you been told your delivery sucks often enough to start figuring it out?

 

Negative, on the delivery. The problem is that some of "you" don't realize that not only the aim-120 is bugged. My problem is that I see people that only fly one plane in lomac, and they show no interest in the other (people flying the mig hate the f15 or people flying the a10 hate the su27), I hate it when people are so narrow-minded, are aware of that and are proud of it.

 

back on topic, but if the missile needs to "seek" with it's seeker (which had a FOV of 12 according to a previous post) and can depress it as far as 180 degrees, what is the turn rate of the scanning beam? I mean without knowing the turn rate of the seeker head nobody can judge, let alone model the preformance.

 

*I think of the seeking process as a spinning tube mounted on a flat surface (the missile body), the tube that spins can bend upto 90 degrees off horizontal. So when the tube sping, and bends by 90 degrees, it has a 180 degree "radar disk" emitting perpendicular to the missile body.

 

 

I suck at paint(ing) :|

[GGTharos]

No, your delivery sucks. Period. Wether other people are focused on one plane or another gives you zero dibs to judge then in any way, or to be derogatory. Regardless of which, you focus on being derogatory to F-15 pilots. Stop it.

 

 

Back to missiles: Your drawing is to the point and pretty much correct. You're right, we don't know the scanning rate, but we can guess it - in essence you can think of it as having the same scan rate as the F-15's radar (simply ebcause it's easy to see what the antenna is doing on the 15) - this has less to do with the ability of the servo to pan the antenna itself - you also need to scan in a specific direction long enough to register a solid 'hit' and get all the info you need. Once you're 'locked on' things change a bit.

 

If you're about to surmise that under those circumstances, scanning 180 deg would take too long to be of practical use, you'd be right ;)

 

The AMRAAM (and pretty muhch all ARH missiles) will typically scan a 'killbox' when they go active (Assuming they're not coming off the raile locked on target) - to give you a better idea, the simplest way to define a dkillbox is this:

 

I have a target which will do a max of 600kts.

The time between sweeps is 5 seconds. Ie. I repaint the target every 5 sec.

If the last update I have is 5 sec old, I know that this aircraft could have gone about 0.8nm forward (if my math is right)

 

So, I will scan in a radius of 0.8nm around the target.

 

Now suppose my update for some reason is much older: The target beamed, or whatever, and the track is gone. The track is approximately 18 sec old, which means I need to scan a volume of 3nm around the target to make sure I capture it.

 

You would NOT scan the whole 180 deg. See what I mean? The ability to gimbal to 180 deg is useful for use with special trajectories and final intercepts where the missile may have to maneuver radically or use a special trajectory where it needs to look to the side to see the target.

 

Even then the 180 is not *strictly* necessary but i nreality you much accound for delays in homing navigation which may cause the seeker to move to track the target before the missile turns, so that gives you some extra 'leeway' for the seekr to pan during agressive target maneuvers.

[169th_DedCat]

Good summery GGTharos.

 

Even in the case of a maddog ARH missile shot, I doubt the AMRAAM (or the Adder for that matter) would use a killbox for the full horizontal and vertical 180+ degrees that its gimbals may allow. Not only is search time an issue, but safety would be as well. The limits of the default killbox would probably be on par with the visual aiming circle on the HUD for the AMRAAM. If a pilot needs to make a maddog Fox 3, he wants the missile to go after the target he's pointing his nose towards. If the maddog fails to immediately find its intended target, the pilot doesn't want it to go for another, possible friendly, aircraft that may be much closer but 85 degrees above him. Missiles in LOMAC will. There must be safety restrictions to consider, even when a weapon is told to "go find your own target". It should be more of a "go find your own target, in this general area".

 

Imagine a weapons production company designing a cruise missile that after initially failing to find its intended target, went after the first building it saw. I don't know anything about cruise missiles, but it seems to me that whatever the weapon, restrictions are usually considered for what it will and won't go after outside of the dangerous simplicity of anything as far and as wide as it can possibly see.

[GGTharos]

Yeah DedCat. AFAIK, a 'maddogged' ARH will be looking straight ahead when you launch it: No searching. Although I heard that it -does- do some scanning, but what this scanning -is- is also classified apparently, which is annoying.

 

But I would guess that it is something semi-inelligent, like: if you launch while pulling a 4-5g turn for example, the missile might use something akin to VS and assume that the target you were tracking ebfore you maddogged was ceneterd in the HUD. Them it could calculate most probably maximum deflection in the direction of the turn and just scan along that line quickly until it captures the target.

 

 

If you fire unloaded or close to unloaded though, straight ahead (until it lockes on, obviously then the seeker gimbals to trak the target and if lock is somehow broken it'll initiate a killbox search based on the last known target data) ... speculation on my part of course but I can't see why not :D