American IR Missiles

[GGTharos]

Let me clear up how it works in LO:

 

AIM-120 only has MCU guidance and Active, not MCU, Inertial and Active.

This means that once you drop lock, it goes active, and scans - it scans its FULL gimbals, so it's you re inside 7-8nm within 120 deg cone in front of it, chances are it'll see you.

 

One you lose the MCU (ie. drop lock) the missile will fly straight (not ballistic, not to last known target coordinates ... just straight) and scan.

 

At high altitude the AMRAAM retails its speed well in LO, so you can get a 40nm kill.

 

When you first launch the missile, it'll turn to a collision course with the target - then when you drop lock - it'll still be on that collision course and unless the target moves out of the capture area as mentioned before, it is likely that it will be attacked.

[D-Scythe]

I did what you said. I think the pictures are pretty self-explanatory. The seeker finds the target even when the bandit is not travelling toward the missile, without any outside guidance. It certainly doesn't look like the case of bandit accidentally coming across the AIM120's radar. Another intersting thing I saw is that the missile didn't climb. It didn't even speed up for long, the burner went out within a couple of seconds into its flight, if not less. It definitely seems to be tracking at a distance greater than 7~8nm from the target. And no matter how quickly I break the lock (which was within a half second in all of these tests), the missile either 1) turns directly into the bandit, or 2) starts its climb. I tried shooting it way off-angle, at the edge of the gimbal, but to no avail, it still behaves in the one of the two ways I described.

 

I wanted to test at a greater range using this off-bore approach, but that meant that I would have to shoot outside DLZ and the missile will never have any energy to reach. (I tried it, and as expected it just doesn't have the energy to maneuver.)

 

p.s. I exceeded my upload limit for jpg, so I had to delete some screenshot from the previous posts.

 

No, I didn't mean like that - I'll come up with a track or something later.

[anselm80]

Anyway thanks guys for your attention. I didn't bring this up to cause a stir, or even dispute a point. The fact is I am very much clueless as to how the real AMRAAM behaves. All my perception and knowledge is solely based on how it was portrayed in different sims. Even then, like I said on my first post, my experience with LO is pretty limited, since I just bought this software 5 weeks ago.

 

I just brought it up because AIM120 in LO seems to behave a bit 'smarter' than the AIM120s in different versions F4. In F4, it was easy to tell whether missile has a target, or whether it's in its dormant search mode. Once AMRAAM is launched, F-16's FCC calculates the time to impact and starts a countdown. The HUD displays a letter A and a number of seconds next to it, right below the DLZ scale. Once the number reaches 0, the letter A changes to T and a new number is displayed next to it, indicating that the missile is now tracking a target and is in fact fully autonomous, at which point you can freely break the lock. But if you disengage before this happens, the PK is close to nil.

 

Of course, on the HUD of an F-15 I don't see any of these info, so the only way for me to check the point at which the missile goes autonomous is to devise up some tests where I purposefuly break radar locks prematurely, at different ranges and aspects, to see whether that missile gets lost, or tracks its targets. I was pointing out the scenarios when the missile successfully found its target without my aid, and conversely, when it was unable to find a target without my aircraft's radar lock.

 

"AMRAAM has a radar in the nose of the missile which can lock onto a target. Since this radar is much smaller than the radar in the F-16, it cannot track a target as far away as the F-16's radar. The F-16 therefore must find the target and guide the AIM120 to a point close enough for the AIM120's smaller radar to acquire it. When it reaches this point, the missile becomes autonomous and guides without further help from the F-16." -F4:AF manual pg. 114/716

[GGTharos]

It was a fair question ... I realize it may look like the 120 in LO is smarter, but believe you me - you'll quickly become dissapointed with it, especially if you fly against another player.

 

The count-down is there on the HUD, but it isn't as clear as it is in FC. Obviously, if you drop lock, you lose the count-down, too.

 

Anyway, I think F4 has it slightly under-modelled in that case ... I agree that without the MCU's there ought to be trouble, but mostly on long range shots against maneuvering targets. In other words, consider this:

 

If you were to drop lock about 5 sec before the A reaches 0, you should reasonably expect that the target won't be able to physically move out of the 120's scan zone (though it could do other things to help it ditch the missile at that point), it will thus be detected, and attacked.

 

If the target isn't maneuvering, and lauching and dropping lock a good 5 to 10 sec should theoretically not make a difference since the target is heading tot he pre-computed intercept point and the missile is going to be looking there for it.

 

Of course, we have had 'theoretical' speculations before, which were proven wrong ... example, it was widely assumed that the R-27ET had datalink/MCU capability so that it can be used in BVR. That was wrong - it's actually meant to run down retreating targets, and has no lock-after-launch capability.

[D-Scythe]

Of course, on the HUD of an F-15 I don't see any of these info, so the only way for me to check the point at which the missile goes autonomous is to devise up some tests where I purposefuly break radar locks prematurely, at different ranges and aspects, to see whether that missile gets lost, or tracks its targets.

 

Um, the information is RIGHT there. On the VSD, and the HUD.

 

Anyway, I did my own test. Scenario was that me and a Su-33 are head on, 20 nm away, I turn to the left a bit, and fire the AMRAAM at 15 miles, and break lock right after. I think the screens speak for themselves.

 

 

 

And the result is exactly what I said it would be - the AMRAAM doesn't even come close.

 

 

[anselm80]

Hopefully, these pictures can show you why I thought there is a discrepancy between the AIM120 in LO and AIM120 in F4. (like I said, I don't know which is a more accurate representation.)

 

You saw from my earlier post that that under near identical conditions (MiG25 20miles out), the AIM120 in LO successfully made a kill. As you see in the screenshots, AIM120 in F4 failed to do so. Here are the conclusions or possible explanations that I deduce;

 

1) AIM120's onboard radar gimbal is larger in LO than in F4,

2) LO's AIM120 is smarter at optimizing its flight path. (judging from how long range AIM120 shot in LO resulted in the missile's rapid climbing to maximize its travel distance) F4's AIM120 on the other hand stayed at a relatively flat trajectory despite having launched it at 20nm out.

3) F4's AI engages defensive earlier than LO's, ruling out the possibility of accidentally crossing AMRAAM's search gimbal.

 

I cannot pinpoint which is the correct answer for discrepancy, but I wouldn't be surprised if it's some combination of above 3 possibilities.

 

Anyway here are the screenshots of the last test I performed on F4. You can probably get a sense why I felt that the same weapon in two sims behave a bit differently.

 

p.s. I deleted more screenshots of the previous tests b/c of the upload limit issue, if any of you wants to see them again, I can send it to you via PM.

[GGTharos]

Hopefully, these pictures can show you why I thought there is a discrepancy between the AIM120 in LO and AIM120 in F4. (like I said, I don't know which is a more accurate representation.)

 

Well, since you are trying to figure out the difference I'll try to help you.

 

You saw from my earlier post that that under near identical conditions (MiG25 20miles out), the AIM120 in LO successfully made a kill. As you see in the screenshots, AIM120 in F4 failed to do so. Here are the conclusions or possible explanations that I deduce;

Did the one in F4 fly straight? The target I mean.

 

1) AIM120's onboard radar gimbal is larger in LO than in F4,

It is more correct to say that LO's 120 uses the full gimbal limit for searching, while F4's limits the search to a 'killbox'. The latter is probably more realistic in principle.

 

2) LO's AIM120 is smarter at optimizing its flight path. (judging from how long range AIM120 shot in LO resulted in the missile's rapid climbing to maximize its travel distance) F4's AIM120 on the other hand stayed at a relatively flat trajectory despite having launched it at 20nm out.

Both missiles use a lofted trajectory - the perceived smartness you see for LO's AMRAAM is nothing more than it using a different trajectory and different (lower grade) missile physics - but it always uses the same trajectory.

 

3) F4's AI engages defensive earlier than LO's, ruling out the possibility of accidentally crossing AMRAAM's search gimbal.

That would certainly make a very big difference, even with the scanzone as it is right now in LO's 120.

 

I cannot pinpoint which is the correct answer for discrepancy, but I wouldn't be surprised if it's some combination of above 3 possibilities.

'all of the above'? :)

 

Anyway here are the screenshots of the last test I performed on F4. You can probably get a sense why I felt that the same weapon in two sims behave a bit differently.

 

p.s. I deleted more screenshots of the previous tests b/c of the upload limit issue, if any of you wants to see them again, I can send it to you via PM.

They do behave quite differently in fact, for various reasons. And like I said ... wait until you play against someone online. You'll start to hate the 120 as it is in LO :)

 

Lastly, try an altitude for your shot in F4 that's much higher ... 30000 to 40000.

You're firing near Rmax so you're really helping you missile.

[Pilotasso]

Missiles in F4 are horribly overmodeled. They seem glide forever and act as in the no escape zone way above the marker on the HUD. In LOMAC we got the oposite, with people downright mocking radar missiles by turning arround well inside the NEZ and shove a heat seeker on the chasers face.

[anselm80]

D-Scythe, I shoot 20nm out and I keep getting the kill. I can do this all day long with pretty much the same result all the time. I will try it again tonight with a different heading, location, and distance between the respective aircrafts (I am gonna use a non-MiG25 also, to see if it's the bandit AI that's making the difference). Anyway here are the screenshots from my latest attempt.

 

Here is the how I set it up, MiG25, 20nm out, no waypoints like you said.

 

 

I fired as soon as I got the lock.

 

 

I dropped the lock right away as you can see.

 

 

There is our AIM120, still climbing, high above the bandit, 15nm out. Maybe it's lost, maybe not, we will see.

 

 

Still about 9 nm out, it changed its heading by 2 degrees, it went from traveling straight to a slight descent. It may have detected the MiG already.

 

 

 

3 seconds later, 6nm out, it's making a mad descent, dashing toward the crash course. As expected, it definitely sees the bandit now.

 

 

Poor bugger, my missiles got a lead on him. He's been traversing the plane towards the airport, putting my missile on his 3 O'clock. But it's seems to be of little use.

 

 

Here's the pic right before the impact. Like I said I think the missile's own radar gimbal is pretty big, or at least bigger than what I thought it to be, given the point at which it started maneuvering even without my own guidance.

[D-Scythe]

Just out of curiosity, what task did you set the MIG-25 up for? Because if you have it on "CAP" or "Fighter Sweep", if it detects you it's still going to fly straight at you, and right into your AMRAAM too.

 

In any case, I wouldn't look too much into it. BVR combat in Lock On is pretty arcade-ish right now, and hopefully the entire thing just gets redone from the ground up in the future. In this respect, Falcon 4.0 is far more realistic, IMO.

[anselm80]

Just out of curiosity, what task did you set the MIG-25 up for? Because if you have it on "CAP" or "Fighter Sweep", if it detects you it's still going to fly straight at you, and right into your AMRAAM too.

 

In any case, I wouldn't look too much into it. BVR combat in Lock On is pretty arcade-ish right now, and hopefully the entire thing just gets redone from the ground up in the future. In this respect, Falcon 4.0 is far more realistic, IMO.

 

I didn't set it up to do anything. It just flew around a bit and headed for that airfield. When my missile was about 8~10nm away, it seemed to have noticed it, as it tried to put the missile on its 3, as you can see from the screeshot.

 

Anyway, having played Falcon 4 for 7 years, I wouldn't say F4's BVR is realistic either. You can detect mid-range missile launches from miles and miles away even before the radar onboard the missile goes active. Making evasive maneuvers even easier to perform. In fact, you can fly the entire campaign without ever having to worry about getting shot down A-A. (SAMs on the other hand can be quite deadly.)

 

Watch these 2 movies, and see how the detection of incoming missile can be done at the instant it is fired, thus making identification and preparation for evasive maneuver that much easier. Also, I've read that HoJ is less realiable than a solid radar lock, but for some odd reason in Falcon 4, HoJ is deadlier than radar guidance. That's why the dude piloting in the second movie turns off the ECM near the end.

 

http://rapidshare.com/files/33527959/Missile_test_2.avi.html (only 4mb)

http://www.youtube.com/watch?v=8N-SEWKqWDA (direct feed)

[D-Scythe]

I didn't set it up to do anything. It just flew around a bit and headed for that airfield. When my missile was about 8~10nm away, it seemed to have noticed it, as it tried to put the missile on its 3, as you can see from the screeshot.

 

Anyway, having played Falcon 4 for 7 years, I wouldn't say F4's BVR is realistic either. You can detect mid-range missile launches from miles and miles away even before the radar onboard the missile goes active. Making evasive maneuvers even easier to perform. In fact, you can fly the entire campaign without ever having to worry about getting shot down A-A. (SAMs on the other hand can be quite deadly.)

 

Watch these 2 movies, and see how the detection of incoming missile can be done at the instant it is fired, thus making identification and preparation for evasive maneuver that much easier. Also, I've read that HoJ is less realiable than a solid radar lock, but for some odd reason in Falcon 4, HoJ is deadlier than radar guidance. That's why the dude piloting in the second movie turns off the ECM near the end.

 

http://rapidshare.com/files/33527959/Missile_test_2.avi.html (only 4mb)

http://www.youtube.com/watch?v=8N-SEWKqWDA (direct feed)

 

It's not that bad. Obviously, there are some unrealistic issues with Falcon 4.0, but in terms of the overall outcome, the game still forces the player to execute proper BVR tactics in order to win.

 

Lock On, on the other hand....let's just say it let's people be as unrealistic if they want to and live.

[Kuky]

In that last screenshot the AIM-120 is doing just 835 Km/h... which is very slow for a missile. If that MiG would have evaded just a little bit (and not fly like a numbnut) that missile would loose absolutely all of its remaining energy (which it has very little off at that stage anyway) and MISS.

[Weta43]

GG said -

Let me clear up how it works in LO:

AIM-120 only has MCU guidance and Active, not MCU, Inertial and Active.

 

Actually - it doesn't have either, it simulates the behaviour of MCU's & active radar. It also simulates the effect of inertial navigation, otherwise the missile wouldn't know which way it was pointing between MCU's & would just be ballistic between mid course updates.

Even to stabalise it's flight into a straight line after losing lock (& not just go ballistic in an arc to the ground) it has to use inertial guidance. Also - after reading up on the AIM-120 guidance from a few sources (admittedly sources on the web) it appears that - as I suggested - the intercept course is calculated and loaded before launch ( if the missile is not active at launch ), & that path will be followed if the lock is broken - not a straight line, so if LO's AAIM-120 don't do that - there's something else they could fix ...

[GGTharos]

There's intertia ... but no inertial guidance. Period.

All the LO 120 has is MCU's and Active.

[Weta43]

You're wrong. Period.

Watch the flight of a RL dart - which has inertia but no guidance - thrown up and away.

Nose up at launch, arcing parabolic flight, nose down at landing

Watch the in game flight of the missiles from an MLRS.

THEY have inertia & no guidance.

Nose up at launch, arcing parabolic flight, nose down at landing.

 

Now watch an active guided missile in LO after the radar of the launching plane is tuned off. dead straight till the speed falls to where the missile can't generate enough lift to maintain its course, then nose up as it starts to fall - still trying to climb back to where the course it was originally on was.

 

Not like a dart at all really.

But that's inertial guidance for you.

[GGTharos]

If it HAD inertial guidance ... GUIDANCE ... it would be steering happily along a flight path to the last computed intercept/active point.

Instead, if you fire it on a loft and drop lock, it just keeps going straight.

It may have an inertial auto pilot, but guidance? No.

[Weta43]

And what does an

inertial auto pilot

do if not guide ? (:-)

 

However – I do know what you were saying - that LO’s radar guided missiles’ calculated course to point of impact does not persist after radar lock is broken

Which is wrong, as the real thing does hold onto this data & will fly to the last course computed, but easy to understand as LO's engine will be calculating the intercept course in real time, and to model the actual behaviour would require the whole future course to be plotted & stored somewhere for use once the lock was dropped.