In the document, the missile climbed 59,500 feet for a target that was 200km away. I did some testing with the Phoenix just now. I’m not able to replicate the testing in the document due to some game engine limitations, so I did it on a smaller scale. Here’s the testing done:
It seems to me to be performing as expected in line with the source. At 110km, it would climb roughly nearly 7km. In the 203km range, it should climb 17km to maintain the same 17.5 degree angle to the target. I suspect this would be possible for the missile to do with the current loft code.
I was just attempting the 110nmi shot myself, but I have yet to figure out a good way of finding the altitude of a missile in the replay. How have you gone about this?
The shape of trajectory is very important too. Given that missile flies about 30km when burn ends, if target is far enough, when launched at 10,000m, when target is far enough, missile will climb to 10,000 + sin(15) * 30 = ~17,700m.
However, with 15 degree loft, the missile will waste so much time in lower altitude and experiences higher drag, comparing to missile that climbs at 45 degrees and reaches 17,700m as early as possible.
Also from historical footage we know Aim-54 climbs very aggressively.
110nm shot is not possible due to radar render range but a smaller scale trial is possible.
What it took to find the altitude of the missile was that I would launch the missile, record the altitude that the plane was in, follow the missile until it reaches the apex of its climb, then place your camera where the apex of the climb was located. Then record the distance between your position at the apex climb and the distance of your own plane passing beneath you. Your plane’s altitude would also be recorded in the top left. In my case, the plane climbed about 1km, so I added 1km to that distance.
I see, interesting way of doing things. I really wish Gaijin had given us a missile altitude readout in the sensor view.
In the user missions I created to test missile range, I have no issues with locking targets well outside render range. Granted I had to modify the AWG-9 radar in order to hold a lock above ~180km, but it works.
Seems odd gaijin didnt add “altitude” to the missile data card in sensor view…
Also, as stated by SE, its possible whats wrong with the loft is not so much the loftAngle code but the restrictions (loftTargetElevation and loftTargetOmegaMax). We know for a fact that large missiles benefit more from being at high altitudes, due to a mix of reduced drag and increased impulse from the motor due to the reduction in pressure. It is therefore best for a missile using a solid rocket motor to spend as much of its time in flight at a high altitude.
Likely why the correct term for what missiles do is “trajectory shaping” and not “lofting”. Its not as quick to write though.
I do wonder if it’s somehow possible to extract missile altitude from the replay file itself. Unfortunately I’m nowhere near knowledgeable enough about the game’s code to even begin figuring that out myself, though someone else may be.
I think that so long as the the loft reaches the altitude, and that the missile is fast enough to travel 72.5 nautical miles in the test scenario before striking the target, then the modeling of the missile should be good enough.
I dont bug report anymore. I barely bother pinging mods anymore seeing as stuff like today happens where gunjob didnt really bother reading or understanding my question, and K_stepanovich completely ignored the question despite answering a different question of mine on another thread.
Gaijin will ignore any and all sources and evidence so long as it doesnt fit in their world view.
This is a completely out there suggestion, but wouls it be possible to make a user model “plane” using the AIM-54 and just “fly” it? You could at the very least see if the missile can even reach the required altitude on 30 seconds of motor brun from the expected launch condition
These issues aren’t mutually exclusive, but I want to hedge bets that excessive drag compounds lofting issues. That, plus the targetOmega could help alleviate some issues. The reason I’m hung up on drag is that it progessively gets worse as speed increases, which almost certainly affects it adversely in any stage, modified lofting or not.
Terminology is perfectly fine, the AMRAAM enhanced the maximum ballistic range solely with trajectory shaping. AIM-54 being much older, and with far less complicated guidance systems can’t possibly achieve a peak efficiency loft. It simply doesn’t have the necessary sensors and hardware.
As Direct support has shown, loft is fine. Missile drag is far too high. I’ve already explained this.
The thing is, i have no idea how to prove drag is too high, nor do I really know where the claim comes from. The CkX for the AIM-54 is alreadybinsanely low in-game, which is why i have my doubts about it being a drag issue, since afaik, it has the lowest drag coefficient im-game for any missiles. (Granted I understand we arent clear on exactly how CkX works)
I think its a lot more likely to be a loft profile issue. Everytime loft has been improved (old loft code → current loft code → dark_claw imrpoved loft code) the missile has made somewhat substantial jumps in performance.
The AIM-54 is a large missile, with a large motor area, and a long burntime, literally all factors which would dictate it would love to be at high altitudes for as long as possible. NASA prelim sims for the ALSM also piint in the direction that simply improving loft angle for the missile significantly improves performance, particularly at range.
Hell, legoCubes test, which literally only modified omegaMax, saw a 20%+ improvement in impact velocity. Clearly the AIM-54 benefits greatly from being at higher altitudes faster/for longer. Much more so than I believe most of us realized.
My best guess is the lack of modelling of drag reduction from the motor’s exhaust gasses while its burning (is there a shorthand term for this?). Other missiles can get away with ignoring it or tweaking the thrust values to compensate as most of them have comparatively short burn times, but Phoenix with its 30 second burn is likely affected disproportionately more.
It would be base drag reduction from motor brun iirc. Could also just shorten it to the basebleed effect I guess, since thats what basebleed shells use to enhamce range.
Thats only 1 part of the equation though. As Ive posted many times here before, rocket motor impulse increases dramatically with altitude, something I dont believe is modelled in-game.
Also, like Ive previously stated, do we have any actual proof the AIM-54 has too much drag? Ive never seen anything detailing actual speeds acheived for a given missile shot.
Best ive seen are:
the inaccurate NASA sim (used publicly available info only)
multiple claims of a top speed of M5.0 (doesnt help a whole lot when we dont know under what launch conditions)
A claim I posted at one point from an alleged AIM-54 test engineer (claimed M6.1 at some point iirc?) But despite that alleged engineer having some fantastically obscure info which lead to finding details about the WGU-29/B being a directional warhead, im still not sure if he is who he claims to be, and never got a further answer from him.
The earlier source you provided has the necessary detail to model this. After the AIM-54 Phoenix reaches the peak altitude stated in the launch conditions given, it travels 72.5 nautical miles before killing the target.
If it ends up traveling less than 72.5 nautical miles before killing the target, then it is too slow.
The missile arrives after 72.5 nautical miles of travel as the target moves at the speed of Mach 1.5.
The source I posted doesnt include what kind of energy state or time it took for the missile to impact the target. Nor does it specify if 72.5nmi is horizontal range, slant range, or total trajectory range. It doesn include trajectory nor does it include impact angle.
In theory it could be used to test if the missile can acheive one permutation of this multivariable problem, but it doesnt garantee said permutation is correct.
Also, you could probably test the loft profile to some degree by either firing the AIM-54 modified to be unguided at a 15° angle and seeing how high it reaches, or maybe by adapting a lower speed target to reach the apparopirate impact point at the required moment, which would mitigate your need for a M1.5 50kft target and 110nmi of range
