Players dont either when they can LITERALLY just flight straight an somewhat low altitude to have total immunity against all radar missiles ingame.
Majority of claimed AIM-54 kills in real life were fighter targets hit during the Iran-Iraq war and that wasn’t even an AIM-54C, those were AIM-54A’s. Clearly their ability against fighter targets wasn’t exactly lacking
Fighter targets who mostly lacked RWR, countermeasures, training, etc.
Oh look, wiki… nice
AIM-54C had specific provisions made to the upgrade seeker to improve capability against sea skimming AShM’s, clearly something that may require enhanced look down capabilities. This has been stated over and over.
provide the capability to track through the target’s beam aspect and to guide on targets in a stream raid".
Stream raid are fighter in a line to the f-14. If you fire missiles to them, all phoenixes will home to the first target despite you launching them to individual targets
AN/APG-59 and N-019 can track target in PD mode both in range and speed with HPRF only. Some complex pre-calculations in acquisition phase and tricks are made, but if the target is tracked in range it doesn’t mean that it is gated well in range against ground clutter due the high range ambiguity.
Why even bother at this point?
We pull every single publicly available AIM-54 source there is out there and the answer is just a mix of “i dont think so” “thats not how we want to model it in-game”, “I dont think you understand” etc…
These bug reports are just a massive waste of time. They couldnt even be bothered to give it a smokeless motor after they started giving them to everything else that had one ffs.
I understand, the gates are way larger than what MPRF would allow. But in a lookdown situation of a fighter A at 10km altitude tracking a beaming fighter B at 5km altitude at a distance of 40km. Thats ~7° under the nose, for simplicity the background is another 40km behind the plane. There’s gotta be some tracking done if they are range gated. I don’t think the range gate is 80km.
We agree that if the fighter B is lower such that the ground clutter is withing the range gate, track is lost. But a gate must be set
CW or HPRF + FM modulation allows both resolution in range and radial speed so targets flying with the same speed and at different ranges will be separated by such seeker.
It also increases target return - to - MBC ratio due the MBC spot size in range.
But it also increases MBC clutter area in the frequency scale due the MBC spot size in range. For example a tail-on target (with radial speed smaller than the minimal MBC radial speed) at a range larger than the MBC min range appear in the MBC clutter because frequenct = speed + range. Without FM this target will appear in MBC-free region.
There is no obvious advantage of having FM in order to see through the notch.
I have already explained this in the topic about Skyflash missile.
Do we have any sources/data even saying what prf it uses? (The missile’s on board radar) It seems like they went through a lot of trouble developing ECCM techniques for it if it is only effective in tracking head-on targets.
This is a bad example
Hf = 10 km
Ht = 5 km
Dh = 40 km - horizontal
D = 40.3 km - slant
Elevation to the target is atan((5 km - 10 km) / 40 km) = -7 deg
Beam width for AIM-7 seeker is 7 deg * 2 = 14 deg - this is why 7 deg is here
MBC starts in range from 10 km / sin (7 + 14 / 2 deg) = 41.1 km to 10 km / sin(7 - 14 / 2 deg) = infinity
Only 41.1km - 40.3 km = 0.8 km separation between target and MBC in range.
But this is not the worst news.
If HPRF is used that means for example 2 km unambiguous range and range gate 0.2-0.4 km will fit all returns from 2.2-2.4 km, 4.2-4.4 km, e.t.c. The range gate will receive all returns from MBC behind the airplane becase MBC is longer than 2 km.
If HPRF+FM is used that means for example frequency shift for 200 m in range is the same as for to 2 m/s in radial speed.
Let’s assume that fighter speed is 300 m/s.
MBC starts in radial speed from 300 m/s * cos(7 + 14 / 2 deg) = 290 m/s to 300 m/s * cos(7 - 14 / 2 deg) = 300 m/s.
Target radial speed is 300 ms * cos(7 deg) = 298 m/s.
Without FM target radial speed is in MBC area.
Target frequency shift is equals to 298 m/s + 40300 m / (200m / 2 m/s) = 298 m/s + 4030 m/s = 4328 m/s
MBC starts from 290 m/s + 41100 m / (200m / 2 m/s) = 4400 m/s to infinity
They are separated well by 72 m/s - this is wider than normal speed gate width.
Ok
Now assume that the notching target with speed of 300 m/s turns slightly towards to the fighter. The angle changes from 90 deg to 75 deg.
Target radial speed changes from 298 m/s to (300 m/s + 300 m/s * sin(90 - 75 deg)) * cos(7 deg) = 375 m/s.
The frequency shift changes from 4328 m/s to 375 m/s + 40300 m / (200m / 2 m/s) = 4405 m/s. The target now doesn’t notch, but target return appears within the notch area from 4400 m/s to infinity.
Yes, spectrum density of MBC with FM is smaller, but if it was 1000 times stronger than the target return w/o FM and becomes 1000 times better because MBC gets 1000 times wider - it still not strong enough, but MBC is much wider. Doesn’t look a good deal.
I know what you mean, but you are forgetting range in the doppler range map. MBC spot size in F increases but it’s center is on the (large) range gate(s) created where the center of the beam is. As you get farther from it, in the noise is reduced and with enough SNR, a traget can be found.
Look at this map. Range is 0 to N range bins(created by the FM) and doppler from 0 to M Doppler bina
You say spot size increases, I agree. But on the range axis the MLC ia centered in the beam center at range 5th bin. If the target is getting tracked and is beaming, near the ground. The target will be in the 4th range bin, its signal return will be lower than the clutter. Now lets go on my first example. The target is on the 3rd range bin. If the side aspect RCS is big enough and SNR is sufficient track can be kept.
Why is the beamwidth 14 degrees? I’m not getting this or misunderstanding what you want to say here.
Of course if the BW is as large as 14° the area illuminated will offer a larger return bandwidth.
Sin(7-7) is infinity, I don’t get your math or notation. But if I’m understanding what you say, a 14° beam centered at -7° in elevation will look from angle (-14° to 0°[horizon]). If its for example ok.
Of course you get a an integrated look area of infinity. But the signal return is not infinity. There’s a point the noise is bliss. And simply ia ignored due to the SNR.
On the doppler range map MBC at f0 is from the altitude return to infinity. But the intensity is not uniform but centered on the beam. Even if you might argue that the MBC is not on the horizon( which is what I think you want to point out), the sidelobes do and they don’t get infinity return because the intersected area goes to infinity.
Think of which ground return is stronger, that at 40km or the sum from near horizon to some x distance the signal isn’t even picked by the receiver!
When you range gate HPRF, you take into account the range bins created by the FM. Look at the doppler map again, if we use these (FM) range bins, the target(if enough SNR) will pop out between the rangebin(s) the MBC is and 0.
Let me answer the other post later, is 4h30am here
Radial Speed, is not the only discriminator, that would be relevant. If sufficiently separated by distance, a similar RCS targets will reflect less power and so the resulting convolved guidance commands would favor the closer target with the falloff aligning with the reflected power formula.
and if separated in angle the conical scan seeker will limit the duty cycle(due to nutation of the scan)of the off axis target, on top of observed power losses due to HPBW of the illuminator (the target would need to be ~84% the range of the referenced target at the -3db angle)
The AIM-7 and it’s derivitives should be able to due to the use of an FM-CW waveform, so range is additionally recoverable so could be further used to filter out non target returns, and arm the warhead when close to intercept.
training was good , it was just that they were using old soviet school technics
You can tell that this doesn’t really work well by taking the F-14 into Air Assault and trying to use the AIM-54 with TWS on targets there.
maverick will work better
it really does which is so weird, it makes me wonder what and AGM-65 armed F-14 would have been like.
As I mentioned previously Skyflash uses purely unmodulated CW (so much so that the radar requires a special unit to remove any modulation present in the CW emission):
It is able to differentiate very close targets using a phase lock loop (and also has excellent clutter resistance)
The problem is this functionality is found on basically all ARM’s. If there is coding limitations or the dev’s aren’t sure how it works then with AIM-120 and R-77 round the corner that may present issues. I don’t see a reason to withhold it from Phoenix, especially if it gets correct G-Pull.
If few targets are within the radar main beam and they are not separated in range or speed the radar tracks the average weighted (based on return signal strength) direction to these targets. In WT this have worked for all radars, radar seekers and even IR seekers (with FoV instead radar beam) since their introduction.
Each target return signal strength depends on RCS, range and its position within the radar main beam.
If one target is slightly closer to the antenna than another, but it is further away from the main beam centerline than the another one, it may happen that return signal from this more distant target is stronger and the radar will track direction closer to this target than to the closer one. Until the range decreses and makes range ratio between them more favourable to the closer target.
Yes, there is no such thing as side aspect RCS in the game. RCS is more or less the same from all aspects.
