R-73 max range launch and LA

[topol-m]

He means the seeker tracked it 30km away. He also pointed out it was a done sized flare. Drones tend to be very big - like your car. It's like a plane coming at you in afterburner, but you can see through the fuselage.

 

Well if its like an afterburner does that mean you should be able to track a fighter with afterburner in tail aspect at similar distances?

[GGTharos]

Yes. Unfortunately you can't hit it though :)

[topol-m]

Yes. Unfortunately you can't hit it though :)

 

Ok but if its tracking it why can`t it be launched?

[GGTharos]

You can launch, but the missile will never reach the target at this distance if it is flying away (or sideways).

Maximum range is always gives head-on against a non-maneuvering target. A tail-chase will be close to 1/4 or 1/5 of that range.

[borchi_2b]

gg tharos, a car is a real bad example.

 

a car is a tiny piece of eshit compared to a fighter, in size and heatsource.

 

remember, the enigne still has about 750°celsius, although it is not in burner. this differs from engine to engine, but you coule use it as referance.

 

a car has a heatsource like a hot, huge fart in the african sun, compared with a turbo jet engine.

 

topol-m, there are to many things way of reality in this so called sim, so please wait for a patch that might fix sertain things.

 

just to mention it. this sim was never ment to be realistic at all

[topol-m]

You can launch, but the missile will never reach the target at this distance if it is flying away (or sideways).

 

Ok. But i don`t want to launch it at 30 km, i just want to launch it a little sooner than when i`m 5-6 km away from the target :)

[GGTharos]

You mean head-on. Head-on if the fighter is not in afterburner the seeker just won't see it any earlier. That's just physics - you're looking at the relatively cold aircraft leading edges.

 

Ok. But i don`t want to launch it at 30 km, i just want to launch it a little sooner than when i`m 5-6 km away from the target :)

[topol-m]

You mean head-on. Head-on if the fighter is not in afterburner the seeker just won't see it any earlier. That's just physics - you're looking at the relatively cold aircraft leading edges.

 

That`s cristal clear. What i mean is: if the missile seeker is able to track a fighter in afterburner at 30 km in tail aspect, I should be able to fire the missile at him in the moment he gets in RMax (Lets say 12 km) and not wait the stupid LA to show up when i`m at 6 km. The only way to recieve LA at 6km when i have 12 km Rmax (in the specific conditions) is if the seeker can`t track the target at distance more than 6 km. My point is this missile`s seeker surely should be able to track targets at much greater distances. In Yoda`s example 30 km - in this case the target you say is like a fighter with afterburner. Even if it`s not 30km but for instance 20 km and my RMax for the given conditions is 12km i should get LA at 12km cause the missile seeker IS tracking the target, so i`ll fire at lets say 9 km and not at 5-6km.

[RvEYoda]

12 km head on is is quite much for a heater

[topol-m]

12 km head on is is quite much for a heater

 

Tail aspect.

[Case]

My point is this missile`s seeker surely should be able to track targets at much greater distances.

Yes it should and it would if and only if the target would have a large enough signature for the seeker to pick up.

 

Clearly the Mirage 2000 you are engaging does not fit those descriptions, and I doubt there is any aircraft in LockOn which would fit those descriptions.

[topol-m]

Yes it should and it would if and only if the target would have a large enough signature for the seeker to pick up.

 

Clearly the Mirage 2000 you are engaging does not fit those descriptions, and I doubt there is any aircraft in LockOn which would fit those descriptions.

 

Ok but Tharos said the drone in Yoda`s example is like a fighter with afterburner. I can`t test it now but lets assume i put a F-15 with after burner ( +1 engine if the mirage is generating too little heat with one ;)) the missile should track it pretty far away in tail aspect, will i get LA at Rmax?

[Case]

What i mean is: if the missile seeker is able to track a fighter in afterburner at 30 km in tail aspect, I should be able to fire the missile at him in the moment he gets in RMax (Lets say 12 km) and not wait the stupid LA to show up when i`m at 6 km.

Maybe you are not aware that Rmax is not a fixed number for a given missile. Rmax is computed from the distance between target and attacker and the closure rate between them. In a head on engagement the closure rate is large (say 500+500km/h), but in a tail chase the closure rate is small, and possibly even negative if the bandit is flying faster than the attacker. This means the missile has to cover much more distance than in a head on engagement.

[Case]

lets assume i put a F-15 with after burner ( +1 engine if the mirage is generating too little heat with one ;)) the missile should track it pretty far away in tail aspect, will i get LA at Rmax?

Yes you will, but Rmax will not be 12 km, it will be a lot smaller because the closure rate is small (or negative, see my previous post).

[GGTharos]

Are you saying that you are in a situation where:

 

1. The target is tail-aspect (you are chasing him)

2. He is inside Rmax

3. No LA

 

 

If 1. is head-on aspect, nothing is wrong. If 1. is tail-aspect, something is wrong ;)

 

Ok but Tharos said the drone in Yoda`s example is like a fighter with afterburner. I can`t test it now but lets assume i put a F-15 with after burner ( +1 engine if the mirage is generating too little heat with one ;)) the missile should track it pretty far away in tail aspect, will i get LA at Rmax?

[topol-m]

Maybe you are not aware that Rmax is not a fixed number for a given missile. Rmax is computed from the distance between target and attacker and the closure rate between them. In a head on engagement the closure rate is large (say 500+500km/h)' date=' but in a tail chase the closure rate is small, and possibly even negative if the bandit is flying faster than the attacker. This means the missile has to cover much more distance than in a head on engagement.[/quote']

 

Man, i don`t know how to explain it better. I`m aware of all these limitations and i don`t think a launch at Rmax is the best choice, but yet i should be given the LA at Rmax when the missile is tracking the target. In fact i, usually when using other missiles, launch somewhere between Rmax and the Range for intensively maneuvering target (don`t know the abbreviation). With this missile i can`t do that, i keep repeating that, because i don`t get the GOD DAMN LA. As long as the seeker is tracking the target the LA should appear at Rmax and i should be able to decide when to launch if i want at Rmax or at 100 metres or i can decide to kamikadze the enemy without firing the stupid missile.:joystick:

Edited May 7, 2009 by topol-m

[topol-m]

Are you saying that you are in a situation where:

 

1. The target is tail-aspect (you are chasing him)

2. He is inside Rmax

3. No LA

 

 

If 1. is head-on aspect, nothing is wrong. If 1. is tail-aspect, something is wrong ;)

 

Yep thats what i`m saying. :thumbup:

[Case]

Yep thats what i`m saying. :thumbup:

That is indeed weird... can you post a screenshot of the HUD in this situation?

[topol-m]

That is indeed weird... can you post a screenshot of the HUD in this situation?

 

I will, but later i`m not on my pc right now.

[Vekkinho]

Your issue might be the in the way you scan and acquire that target you wish to engage with R-73! Are you using radar (I key) or EOS (O key) in BVR (2 key)?

 

I believe you're in the BVR (ДВБ) radar mode and your radar's on. You detect a target (Mirage 2000) and lock it up once the returns are strong enough for radar to track it. This should be waaay beyond Rmax of the R-73 no matter of aspect (head on or chase). So I'd use BVR to scan the skies in front and keep my eye on that contact without locking it. I would use the radar but only to monitor the distance to the target (by watching the position of the target mark (--) relative to the range scale in the left part of the HUD). When target comes close (within 10-15km) I'd toggle the radar off and switch to Shlem (it automatically turns EOS on) as I should already have visual on that target! There shouldn't be any И symbols in the HUD only T indicating active EOS.

 

I'm guessing there might be a problem of getting an LA (ПР) if your radar's on and you locked it up on a target so you'll see missile Rmax and Rmin in the range scale (left part of the HUD) but onboard IR seeker of the missile still doesn't track the target so no LA yet!

[topol-m]

Your issue might be the in the way you scan and acquire that target you wish to engage with R-73! Are you using radar (I key) or EOS (O key) in BVR (2 key)?

I'm guessing there might be a problem of getting an LA (ПР) if your radar's on and you locked it up on a target so you'll see missile Rmax and Rmin in the range scale (left part of the HUD) but onboard IR seeker of the missile still doesn't track the target so no LA yet!

 

 

Ok after numerous tests at different altitudes/speeds/targets/aspects/etc. to generalize (this is going to be long :)) :

1. I could not repeat the case where i am tail chasing and i do not have LA at Rmax. After scratching my head a little bit wondering how could that be i finally got a lucid moment. Vekkinho hinted me at that. The thing is that i probably was using the radar to lock on the target - the result was the enemy fighter that i was approaching unnoticed from behind is getting an alert when i turn on my radar and lock on him so he immediately begins a turn to face me. Thats the moment when the range needed for my missile`s seeker to be able to track him is increasing and even though he is in range max of the missile he is not in track range as his engines are facing the opposite direction. From tail chase we pass to side approach and finally to head on so the so the LA to appear i need to get closer. At the same time Rmax is changing too. As GGTharos said the Rmax is calculated head-on against a non-maneuvering target and a tale chase will be 1/4, 1/5 of that range. So in this situation the range max is increasing - if i initially have 5-6 km Rmax when the bandit begins its turn to face me Rmax begins to increase until it reaches lets say 19 km. At the same time the distance needed for the missile seeker to track is increasing too as the bandit is no longer in tail aspect. So in this given situation with specific distance, speeds, etc. there is the false feeling something is not right as you are approaching and you keep not getting the LA on your hud and at the same time the enemy is far closer than Rmax, while in fact it appears there is nothing wrong and the situation has its explanation :)

2. Another question is though how accurately the distances, at which the specific IR missiles in the game can track a target (at various aspects), are modelled. This is pretty difficult to tell. I can only make test in the game and i don`t have accurate info about the same missile`s performance in reality at different altitudes, ranges, tracking specific targets - fighters, bombers, at different aspects... Yoda gave us an example where R-73 could track a drone (resembling a fighter in afterburner in tail chase) at 30 km - pretty huge distance! How can i observe that in the game? Have no idea. And if it is 30 in tail aspect what should be the track distance in head on or side approach? Pretty important especially in head on because thats what is limiting your early launch (you can`t get LA until the seeker is able to track the target and that will happen much later than the target is in Rmax - in other words if we have Rmax 20km the missile will have enough energy to reach the target if you launch it at 14 km and the target doesn`t perform too energetic maneuvering. But you can`t launch it at 14 km because it can`t track the given target in head on at that distance so you`ll recieve the LA at lets say 8 km.). So here comes the question how close are the tracking distances modelled in the game compared to the real ones? Because of Yoda`s example and the next test I think they should be greater. I tested with 2 targets: B1 bomber - 4 engines in afterburner (1100kph) and F-16A - 1 engine not in afterburner (600kph) in head on. There was pretty little difference in the tracking range with R-73`s seeker. The B1 could be tracked at 12 km and the F-16 at 8 km (the altitude was 13000m, my speed - 1300kph). Shouldn`t there be a bigger difference? Any real missiles info? Also shouldn`t there be more difference in various IR missiles tracking range at different aspects of the target?

Edited May 8, 2009 by topol-m

[GGTharos]

Actually the difference is big - 4km. Keep in mind that radiated heat does not lose energy linearly - ie. if you had say (not real units, just giving you example) energy/distance, for radiated energy it is actually energy/distance^2. So the difference will not scale linearly.

 

This is also why, for example, reducing aircraft RCS by a factor of 10 reduces detection range 50%, not down to 10% (although for radar it's worse, it's energy/distance^4)

 

So LOFC has it right. The numbers are reasonable, even if not necessarily real.

[topol-m]

Actually the difference is big - 4km. Keep in mind that radiated heat does not lose energy linearly - ie. if you had say (not real units, just giving you example) energy/distance, for radiated energy it is actually energy/distance^2. So the difference will not scale linearly.

 

This is also why, for example, reducing aircraft RCS by a factor of 10 reduces detection range 50%, not down to 10% (although for radar it's worse, it's energy/distance^4)

 

So LOFC has it right. The numbers are reasonable, even if not necessarily real.

 

I knew it for the RCS but didn`t know that about radiated heat. Now the numbers really look more reasonable, though more realism in missiles stats (speed, range, energy,G-s) and behaviour (flight path, stable lock maintenance) would be great.

[GGTharos]

Not all of this is possible within LOFC (but we can hope for some things!) ... DCS will have much better physics modeling I think.

[Vekkinho]

As I said Rmax of the R-73 doesn't necessarily mean it's a tracking Rmax of it's IR sensor!