Air to Air Missile Flight Physics and Logics, Take two!

[SwingKid]

For guys like me who just want the comparative picture, what is the comparison between Falcon 4.0s modelling of missile kinematics and sensors (FF3/SP4 versions) and LOMACs (1.1 version).

 

I'm glad you asked that question! 8)

 

Besides actual performance and envelopes, are they governed by the same parameters? For example does the IR world in LOMAC feature parameteres such as gimbal limits, seeker tracking rates, irccm capabilies, sun IR properties, flare IR properties, ground / sky IR properties, aircraft IR properties based on engine state, engine cooldown times, etc?

 

I haven't kept up to date with the very latest third-party Falcon 4 modifications, but the last time I checked, the missile modelling in both sims was IMHO somewhat inaccurate.

 

Falcon 4.0 has an advantage in the missile's physics model, in that the missiles actually accelerate and decelerate according to some physical laws, but as far as I can tell, the correspondence of those laws to reality may be limited. The drag model is seriously oversimplified. As a result, the missiles all have much longer range than they do in real life, and BVR combat doesn't really resemble reality. Someone once tried "tweaking" the missiles to give them realistic absolute max range performance, but that ended up destroying the missile's performance against maneuvering targets in terminal maneuvering and it almost always missed. The Falcon 4 "missile physics" model is thus more advanced than Lock On's, but still too simple- a poor physics model can be even worse than a "non-physics" model.

 

Lock On uses a lot of scripting in missile behavior to control acceleration, maximum speed, deceleration, lofting etc. As a result it's easy to point out details that don't work as they would in real life, but the overall "big picture" of missile behavior is actually a little closer to real life - with the notable exception of the supremely important AIM-120, whose real-world performance remains a topic of continuous research and debate.

 

The result is that the missile speed is wrong and the AIM-120 underpowered, in Lock On, but the range is wrong and the AIM-120 overpowered in Falcon 4. Since accuracy in range is more important than speed IMHO, the advantage should go to Lock On, except that the AIM-120 range issue in both sims makes it closer to a tie. I think it comes down to preference, which weapons and missile performance characteristics are most important to you. It also means I consider this a prime area where Lock On v1.2 could get a serious leg up on the Falcon community, if only we worked on the missile modelling instead of... more flyables... :wink:

 

People have brought up gimbal limits, trajectories, and other parameters in the past, but in my research I haven't found serious problems or differences in these regards in either sim. I consider them details that don't so much change the "big picture" of whether a missile will hit or miss, so much as things like speed, range, turn performance and drag.

 

-SK

[Kula66]

From what I know you can notch the radar when the closure rate read by the Emitters radar is equal to the Emitter Speed.

 

I heard figures of 43mph difference being the gate speed ...

 

Interesting thread gents ... I've never been convinced by the accuracy of LO notch modelling ... if an a/c notches you, and you turn 20degs off course ... surely he should reappear ... often doesn't.

 

Somethings not right ... to my simple brain :)

 

James

[Sharpshooter]

Sharpshooter, that's not what I meant - there ways to simualte the real effect without simulating reality such as it is. When you do try to simulate reality, you get into trouble ... when I say slow, I mean -slow- ;)

 

I mean an hour to figure out if your missile hit or not ;)

 

But you know, we can upgrade the sim without overloading everything, at least you would have said the same thing about the AFM... and there it is... it is not overloading my processor at least, and it`s pretty realistic over the old FM, don`t you think ? I think the same could be done with missile physics and logics. ED just has to find an equilibrium between realism and processing time, so we don`t end up waiting an hour for a missile to hit a target.

[Sharpshooter]

Also, there's the issue of notching ... it seems that it is modelled incorrectly. Right now, to get intot he notch one had but to beam the threat radar - but from what I've read, an aircraft could maneuver to prevent the target from entering the notch. This, along with the explanation of what the notch gate is and the physics behind it, suggests that you would notch the enemy aircraft if you flew perpendicular to its flight path, NOT perpendicular to its radar beam.

 

Oh no, not this again... :cry: We had a huge debate over this a year ago on the UbiSoft forum, I had to draw all these pictures and stuff... it wasn't pretty.

 

Lock On has this correct. You notch the radar by flying perpendicular to the radar beam. You cannot take a target out of the notch by turning your own aircraft - while this does change the closure of the target, it also changes the closure of the ground behind the target by the exact same amount. To a Doppler radar, he's now a different-colored snowman in a different-colored blizzard, but still just as invisible.

 

-SK

 

This means, the only way to not be notched is looking up with your radar.

[Kula66]

 

But the radar beam moves from side to side and up and down ... over a large angle, so how do you fly perp to it if is swinging from side to side?

 

James

[SwingKid]

This means, the only way to not be notched is looking up with your radar.

 

I'm not sure this would work - you would have to bypass the radar filter circuits electronically in the look-up situation. The original APG-63 retained a pure pulse mode for this purpose, but I think it was deleted in later radars when they realized chaff can mask a low-closure target look-up just as effectively as ground clutter does look-down. Not sure though.

 

But the radar beam moves from side to side and up and down ... over a large angle, so how do you fly perp to it if is swinging from side to side?

 

When it swings away, it is no longer looking at you and cannot detect you regardless if you are beaming or not. You only need to notch the radar beam when it is pointed directly at you.

 

The problem is mainly, what to do when you are painted by multiple beams from different directions - it's usually only effective to beam one radar at a time. This is where wingman tactics become useful.

 

-SK

[Kula66]

I guess it boils down to how narrow the beam is ... if it is an a/c width then I see what you mean ... if is wider and you are painted by an arc of the beam then this wouldn't work ....

 

James

[Sharpshooter]

This means, the only way to not be notched is looking up with your radar.

 

I'm not sure this would work - you would have to bypass the radar filter circuits electronically in the look-up situation. The original APG-63 retained a pure pulse mode for this purpose, but I think it was deleted in later radars when they realized chaff can mask a low-closure target look-up just as effectively as ground clutter does look-down. Not sure though.

 

But the radar beam moves from side to side and up and down ... over a large angle, so how do you fly perp to it if is swinging from side to side?

 

When it swings away, it is no longer looking at you and cannot detect you regardless if you are beaming or not. You only need to notch the radar beam when it is pointed directly at you.

 

The problem is mainly, what to do when you are painted by multiple beams from different directions - it's usually only effective to beam one radar at a time. This is where wingman tactics become useful.

 

-SK

 

I guess we`ll never know, nothings infalible, though the look up does work in LockOn, I use it a lot. Radar lock lost to chaff is not modeled at all in LockOn AFAIK.

[SwingKid]

I guess it boils down to how narrow the beam is ... if it is an a/c width then I see what you mean ... if is wider and you are painted by an arc of the beam then this wouldn't work ....

 

Why not? If you are painted by an "arc" of the beam, then the ground behind you is being painted by the same arc, right?

 

-SK

[169th_Crusty]

SAM - Situational Awareness mode or something. Falcon 4 had it.

 

Yes... and if I remember correctly it was part of the "easy radar" :wink:

[Guest ruggbutt]

SAM - Situational Awareness mode or something. Falcon 4 had it.

 

Yes... and if I remember correctly it was part of the "easy radar" :wink:

 

Then my pilot buddy is using easy radar when he's flying out of Luke AFB. :shock:

[ApolloFarStriker]

SAM - Situational Awareness mode or something. Falcon 4 had it.

 

Yes... and if I remember correctly it was part of the "easy radar" :wink:

 

SAM is a submode of RWS (Range While Scan) it is very there in the real jet.

[Trident]

Question is - is it there in the real F-15C? That's not a given, although it may simply be called differently.

[enigma6584]

Could you tell us when he started flying the F-16, what version of the F-16 or what type of AMRAAM he talks about ?

 

I spoke to him at length about the community here. He was impressed that we all know about notching, beaming, WEZ, PK, etc. He said he'd love to get me and a couple of guys up in a '16 and he thought that we'd do very well. He said his students have a hell of time w/instruments and simulators. I told him the story about how I finally figured out how to calculate the heading needed to properly beam an opponent. I explained that I used to do the addition or subtraction before I realized the HSI was there to "do the math" for me. He laughed at length and stated that a couple of weeks ago he had explain to his students the exact same process. He also said that he'd probably suck bad if he tried to fly any of the sims on the computer as they have no tactile input. He said he can feel what the airframe is doing, and what he can do just by the G's on his body. I'm thankful that this guy is a fantastic human being and that when he has time that he'll chat w/me. I thank him often for that and for his service.

 

I'm going to put a bunch of LOMAC vids on a DVD for him so he can see what "fun" we have. He was also impressed w/the TrackIR technology. He had no idea that was available.

 

Very interesting. I bet once you show him those vids, even he will go out and buy this simulation. Help train his students mind you. :wink:

[Guest ruggbutt]

He said he hates the simulator.......lol. I guess if there was a choice he'd rather fly. I know I would.

[169th_Crusty]

SAM - Situational Awareness mode or something. Falcon 4 had it.

 

Yes... and if I remember correctly it was part of the "easy radar" :wink:

 

SAM is a submode of RWS (Range While Scan) it is very there in the real jet.

 

Yes it is! I went back to the manual (F4 SP3) and ... there it was :roll:

It`s been too long!

[GGTharos]

SK, I assume the notching issue then arizes from the simple fact that the speed fo the ground is measured along the length of the beam, that's fair ... didn't think on it before.

 

But in that case, why have I heard that maintianing lock depends a lot on your own aircraft's aspect to target?

 

I got that one from a real F-16 pilot ... I wasn't able to ask more.

 

Anyway! Back to missile physics ... according to minizap a 40-5k shot at a receding target (target receding at 480 knots) you've got an rmax of 20nm or so ... that's the launch range, not flight range. Again, this iisn't reflected in lock on ... but when playing FF3 this does seem to be more the case than not. Range is cut by a third to a half against low flying supersonic targets, naturally.

 

Edit: Oops, I was wrong. It's about 14-15nm against a target at 5k altitude ... or almost any altitude for that matter against a receding target ... this is just fine, but LOMAC essntially cuts -that- range in half ...

 

To be a little more clear, it -seems- to me like LOMAC jsut models drag too heavily at lower altitudes, or /something/ of this sort, since according to minizap the difference in Rmax in a high to low shot and a high to high shot is very very similar against a receding target.

[wsoul2k]

Anyway! Back to missile physics ... according to minizap a 40-5k shot at a receding target (target receding at 480 knots) you've got an rmax of 20nm or so ...

 

Sorry GG but what you mean with receding :oops:

 

o dont wanne get out of topic here can you send what you mean to my e-mail wsoul1974@hotmail.com or r.f.m@terra.com.br

 

tks

 

PS I dont know if the PM is working this is why i post my question here ok 8)

[GGTharos]

That just means that it's going away :)

 

As in, you're on its tail, chasing it, and its probably pulling away, so my use of the word is probably not compleetely correct :)

[zzzspace]

So the 120C would be a virtual death ray ;)

 

On a practical note; if that were made so in the sim then Lock On A-A would become a bit pointless (and boring), we could just assume the Eagle + AIM-120 will win, and go play in the mud, minus any fighters in our missions. But as always, it's the skilled operator, and not so much the tool they use which makes all the difference.

 

Personally, I like what I'm seeing in 1.1 (with modded demo), except it's a little too easy to energy kill all missiles with a few sapping manoeuvres, and the countermeasures seem perhaps a little too effective, but I can live with this as it is still a challenge to win and stay alive, and all the goal posts have been moved in 1.1, so it remains interesting for developing tactics. If I knew my BVR missile was going to kill >95% of the time, I’d not enjoy that a whole lot.

[GGTharos]

zzzspace, when I say virtual death ray, I imply a fighter maneuvering withou the benefit of using countermeasures - obviously nothing's impossible ... but I understand that the 120 cannot be kinematically defeated within 8nm or so. That means slaloming, turning around adn kickng the cans,a nd so on won't see you escape the missile ... you'll have to use countermeasures.

 

Mind you even in this case the pk is soemthing like .85, not 1 so .. ;)

 

Speculatively speaking, that is! And I agree with you .... missiles need slightly better logics and some remodelling of physics (they really seem to lose speed at low altitudes just a -little- too fast)

 

And i don't mean jsut the 120's...

[zzzspace]

I´m against ED getting the 120C better it´s already killer, I get only but kills in no escape zone.

 

 

Nah, I had Su-30s defeating AIM-120s in 1.1 last night between 3-6 nm range. As always, decoys, altitudes, maneuvers and approach aspects mean there is no such thing as a true 'no-escape zone'.

[GGTharos]

I'll second that.

[zzzspace]

Speculatively speaking, that is! And I agree with you .... missiles need slightly better logics and some remodelling of physics (they really seem to lose speed at low altitudes just a -little- too fast)

 

And i don't mean jsut the 120's...

 

 

I see 8)

 

Yeah the Buks are pretty easy to defeat by energy bleeding, then you just push them down low so that they intersect with the dirt. That shouldn't happen with, as you say, better interception logic/ballistics.

[GGTharos]

Yeah ... I hear the SAMs now will head high and then dive onto the target, which should fix a numebr of problems.