R-27 ET "Anomalies"

[EvilBivol-1]

Also, there is no inertial navigation or different phases of flight. Since the seeker is locked on before you fire, it simply uses proportional navigation as soon as it leaves the rail. Of course, this is assuming you cannot fire it otherwise.

[EvilBivol-1]

And even more also... :D

 

According to Chizh, the R-27Ts ability to find target's post-launch is a result of all of Lock-On's IR missiles' ability to re-target during flight, which was necessary to allow them to bite the flares.

[Pilotasso]

hmm that explains how that got through to the code. I was scratching my head over the logic of the ET's capability to swich plane targets. Having this as a ghost capability from swiching from plane to flare explains alot.

 

Then I think theres no much difference from the way IR and radar missiles operate in LOMAC?

 

AMRAAM and ET are maddoggable and swich to reaquire targets except each as its diferent seeker parameters wich are basicaly the same but with different values?

[GGTharos]

I still have a problem. Suppose indeed, as it seems, that IRL the R-27ET is:

 

- a missile with inertial guidance in first phase of flight

 

Get off the INS already. It really means little until otherwise indicated. Almost all missiles need it ;)

 

- limited, not so sensitive IR seeker in the end-run

- having no data-link

- being not a beam-rider of course

- requiring seeker lock BEFORE launch

 

... then I completely do not understand why they have both a -T and an -ET version?

 

It must be quite evident that the ET, with its long range, is completely useless, since you cannot launch beyond the seeker limit?

 

I would say in those circumstances T = ET, functionally spoken.

 

Or did I miss something again :)

 

Yes. It's for tail-chases ;) Your enemy turns around before you can launch an R-73 at him, the 27ET WILL catch up. ;)

And as Evil stated, the radar missiles have issues when fired from the real quarter.

[EvilBivol-1]

AMRAAM and ET are maddoggable and swich to reaquire targets except each as its diferent seeker parameters wich are basicaly the same but with different values?

AFAIK, in Lock On ARH missiles will actively scan the sky, unlike IR and SARH, whose seekers remain fixed, pointing at last known coodinates.

[Alfa]

JJ .. he is busy :) and he is in US now .

 

Yeah he told me so the last time I talked to him - didnt know that he went to the US though :)

 

Cheers,

- JJ.

[Bouddha]

hmm that explains how that got through to the code. I was scratching my head over the logic of the ET's capability to swich plane targets. Having this as a ghost capability from swiching from plane to flare explains alot.

 

Then I think theres no much difference from the way IR and radar missiles operate in LOMAC?

 

AMRAAM and ET are maddoggable and swich to reaquire targets except each as its diferent seeker parameters wich are basicaly the same but with different values?

 

Hi !

 

I'm not sure to clearly understand one thing.

 

In real life, an R27ET launched "Maddog" should not be able to lock a target ?

Shouldn't an 27ET be able to reaquire in real life ?

 

Thanks for your inputs & best regards

[Pilotasso]

If you read previous pages you would see the answer to that. Its not that simple IRL.

[Bouddha]

If you read previous pages you would see the answer to that. Its not that simple IRL.

 

I must confess, that I have not followed from the beginning the discussions.

Therfore when starting to read this interesting post, I have read the first 10 pages then jumped to the last 2 pages. :icon_redf

 

May I ask you at which page the answer is or should I read the 34 pages ?

 

thanks & regards

[AJ.eightFive]

I think we can forgive people for not reading all of the previous discussion at this point... all 360 posts worth ;).

[GGTharos]

In -theory- you could maddog it, and it could reacquire.

 

Realistically, if you did try that, you would very likely hit nothing but hot air due to the small FoV of the seeker and seeker walk-off.

[Pilotasso]

I think we can forgive people for not reading all of the previous discussion at this point... all 360 post's worth ;).

 

Yeah from now on read just the last 8 pages, and avoid the flame war before them.

[EvilBivol-1]

In -theory- you could maddog it, and it could reacquire.

I object your honor! :D

[GGTharos]

Hey, I am only talking about the missile, what the WCS does/does not do with it, is another matter. :D Personally I think maddogging heaters is a waste of a missile in real life, which is why it isn't done.

[AJ.eightFive]

The brevity code manual for NATO multiservice operations mentions only the AIM-120 and AIM-54 for usage of the term MADDOG. Maybe we need to start using a different descriptor for launch-without-lock R-27ET's... I propose, HAPPYCAT...

[chennuts]

The brevity code manual for NATO multiservice operations mentions only the AIM-120 and AIM-54 for usage of the term MADDOG. Maybe we need to start using a different descriptor for launch-without-lock R-27ET's... I propose, HAPPYCAT...

"Lost Puppy"

[HubMan]

Hi all, :)

 

I'm a frequent reader of lockon.ru, but I never had the opportunity to post here... At least until I found this 36 pages thread (I read them all ;) ) and some excellent posts that really pushed me to post the following questions / remarks. :)

 

1. About the Chaff being more effective on a head / tail aspect than on the beam : does it only happen when the radar of the Fox 3 is in look-up mode or does it occur in look-down as well ?

 

As already said :

 

- Chaff rejection is mostly based on Doppler filtering. Thus, a radar in Doppler mode can reject chaffs quite easily in head / tail aspect because chaffs slow down quite fast after being ejected (large radial speed difference => consequent difference in the Dopppler shifts => easy filtering) but with more difficulties on a beam aspect (close radial speeds => small difference in the Doppler shift => difficult filtering)

 

- but chaff rejection is also dependent on the "geometry" (projection) : from the radar point of view, an aircraft seen on the beam will "move" away pretty fast from the cloud of chaffs (different blobs) and can be rapidly reacquired (if non manoeuvring...), by having the radar doing the same correction / interpolating the target trajectory as before.

On the other hand, if the target is on a head/tail aspect, the aircraft will appear for a short while "over"/"through" the cloud of chaffs, and that will make the job of a non-doppler radar more complicated.

 

Fighters radars tend not to use doppler filtering in -search- mode while looking up (not really needed due to not much ground clutter + no vulnerability to "beam"/"doppler notch manoeuver" + no detection / tracking range decrease).

Under these conditions, a radar could be more easily fooled by chaffs on a head / tail aspect than of the beam.

 

While looking down, it is the other way around : a search radar would be in "Doppler" mode and would be more easily deceived by a target using chaffs while on a beam than head/tail aspect.

 

A modern radar in "track" mode is behaving quite differently than in "search" mode : the chaff efficiency is -very- low, and the monopulse seeker of the AMRAAM is very unlikely to get fooled easily by that kind of counter measures.

I was wondering if ED wouldn't have worked on the "gameplay" by modeling the airborne "tracking" radars (and probably the behavior of SARH seekers) the same way than basic "search" radars ?

 

 

About the inertial guidance of the R27-TE : couldn'it be related to the way the missile is fired ?

 

Most of the Fox 2 are fired from a "rail" launcher : there is no "separation" / or really "ejection" from the aircraft.

But in the case of the R27-TE, the missile has to "clear" itself from the aircraft it's not a dogfight missile, it behaves like a heavy Fox 1.

Couldn't the inertial guidance be used for this purpose : move the missile far away (low) enough from the firing aircraft to make sure it doesn't collide after igniting its engine ?

 

About the seeker acquisition when the R27-TE is fired in "Mad Dog"

 

I think that an AIM-9 Sidewinder in uncaged mode is moving its seeker around, and that Lockon is only modeling the "boresight" mode where the seeker is not moving at all.

I'm wondering if it couldn't be the same with the R27-TE and the other russian Fox 2 : fire it in Mad Dog and it will acquire the first IR source that looks like a plane engine exhaust (gaz) within a certain angular limit, not determined by the seeker "proper" field of view (which is very small), but by a larger cone determined by the scan rate of the seeker gyroscope etc...

 

 

Hope it helps :)

 

Ciao :)

 

Hub.

 

PS : sorry for my english, it's not my mother language :)

[169th_Crusty]

...PS : sorry for my english, it's not my mother language :)

 

LOL, Your english is very good!:thumbup:

[GGTharos]

Hi all, :)

 

I'm a frequent reader of lockon.ru, but I never had the opportunity to post here... At least until I found this 36 pages thread (I read them all ;) ) and some excellent posts that really pushed me to post the following questions / remarks. :)

 

1. About the Chaff being more effective on a head / tail aspect than on the beam : does it only happen when the radar of the Fox 3 is in look-up mode or does it occur in look-down as well ?

 

As already said :

 

- Chaff rejection is mostly based on Doppler filtering. Thus, a radar in Doppler mode can reject chaffs quite easily in head / tail aspect because chaffs slow down quite fast after being ejected (large radial speed difference => consequent difference in the Dopppler shifts => easy filtering) but with more difficulties on a beam aspect (close radial speeds => small difference in the Doppler shift => difficult filtering)

 

- but chaff rejection is also dependent on the "geometry" (projection) : from the radar point of view, an aircraft seen on the beam will "move" away pretty fast from the cloud of chaffs (different blobs) and can be rapidly reacquired (if non manoeuvring...), by having the radar doing the same correction / interpolating the target trajectory as before.

On the other hand, if the target is on a head/tail aspect, the aircraft will appear for a short while "over"/"through" the cloud of chaffs, and that will make the job of a non-doppler radar more complicated.

 

Fighters radars tend not to use doppler filtering in -search- mode while looking up (not really needed due to not much ground clutter + no vulnerability to "beam"/"doppler notch manoeuver" + no detection / tracking range decrease).

Under these conditions, a radar could be more easily fooled by chaffs on a head / tail aspect than of the beam.

 

Once you put chaff into the air, you create a 'clutter' situation, and the radar goes into doppler mode. It's almost the same as if you were looking at the ground when you have chaff floating about. The radar can tell it's cluttered up without having to know wether it's looking up or down, but that might help too.

 

While looking down, it is the other way around : a search radar would be in "Doppler" mode and would be more easily deceived by a target using chaffs while on a beam than head/tail aspect.

 

A modern radar in "track" mode is behaving quite differently than in "search" mode : the chaff efficiency is -very- low, and the monopulse seeker of the AMRAAM is very unlikely to get fooled easily by that kind of counter measures.

I was wondering if ED wouldn't have worked on the "gameplay" by modeling the airborne "tracking" radars (and probably the behavior of SARH seekers) the same way than basic "search" radars ?

 

I really don't know what you mean here ... yes, search vs. track behavior is different in a number of ways for a number of reasons, but chaff rejection would be done better by an aircraft's radar typically (more processing power, more radar power, yadda)

 

 

About the inertial guidance of the R27-TE : couldn'it be related to the way the missile is fired ?

 

Most of the Fox 2 are fired from a "rail" launcher : there is no "separation" / or really "ejection" from the aircraft.

But in the case of the R27-TE, the missile has to "clear" itself from the aircraft it's not a dogfight missile, it behaves like a heavy Fox 1.

Couldn't the inertial guidance be used for this purpose : move the missile far away (low) enough from the firing aircraft to make sure it doesn't collide after igniting its engine ?

 

About the seeker acquisition when the R27-TE is fired in "Mad Dog"

 

I think that an AIM-9 Sidewinder in uncaged mode is moving its seeker around, and that Lockon is only modeling the "boresight" mode where the seeker is not moving at all.

I'm wondering if it couldn't be the same with the R27-TE and the other russian Fox 2 : fire it in Mad Dog and it will acquire the first IR source that looks like a plane engine exhaust (gaz) within a certain angular limit, not determined by the seeker "proper" field of view (which is very small), but by a larger cone determined by the scan rate of the seeker gyroscope etc...

 

No. It will lock onto to the FIRST IR source it sees ... be it the ground, a cloud, or the sun reflecting off of some lake below. This isn't modelled in LOMAC, and this is why maddogging heaters shouldn't be allowed, since the problems inherent in doing so RL are not tranlated to similar problems in the game.

 

One the missile is locked onto a source, an aircraft crossing in frton of it may well in fact be rejected as a decoy ...

 

 

Hope it helps :)

 

Ciao :)

 

Hub.

 

PS : sorry for my english, it's not my mother language :)

[Pilotasso]

OMFG this thread was ressurrected?!:shocking:

[GGTharos]

Are you ok? You look like you've seen a ghost!

[Pilotasso]

:lookaround: :fear:

 

Please let this one go. ;)

[HubMan]

Hi GGTharos, :)

 

Thanks for your answer. I'm afraid I was not rigorous enough in my first post. If you don't mind and still have the strength to follow this subject, I would like to clarify some points (by the way, my apologizes to Pilotasso for resurrecting the Evil Dead Thread :) )

 

Here we go : roughly said, a typical fighter radar for the lomac historical period can operate in :

 

- "search"/scan mode where it scans a large volume of airspace to detect an aircraft using Pulse technology and/or Doppler technology.

 

- "track"/lock mode, where the monopulse technic (phase or amplitude) is generally used to determine the target position as accuratly as possible.

 

Those two behaviors are quite different, a SAM site will use different physical radars or even vehicules for each of it, but considered that a fighter does not have that much room to spare, the same antenna and as much common components as possible are used.

 

Anyway my point is :

- a modern aircraft radar in -track- mode is very difficult to be deceived, chaffs are almost useless and a beam manoeuver will usually be inefficient (Shaw wrote in its "Fighter Combat" page 353 that chaffs are quite efficient while used on the beam against a Doppler radar equipped opponent, but the book is getting quite outdated on some technical points...)

 

- a radar in "search"/scan mode can be fooled with less difficulties : chaffs and beam can work etc...

 

- missiles radar are of the -track- type. Despite being less efficient / powerfull than an aircraft radar they do not lose a lock easily.

 

Lomac is a game. I'm afraid the team modeled the tracking radars guiding the Fox 3 (and the Fox 1...) almost the same way than the search radars : that's not realistic, even though, to my opinion, it greatly improves the game play (the same way than the RWR's can detect in the game the launch of Fox 1 not using CW illumination ;) ).

 

 

Hi all,

 

I'm a frequent reader of lockon.ru, but I never had the opportunity to post here... At least until I found this 36 pages thread (I read them all ;) ) and some excellent posts that really pushed me to post the following questions / remarks.

 

1. About the Chaff being more effective on a head / tail aspect than on the beam : does it only happen when the radar of the Fox 3 is in look-up mode or does it occur in look-down as well ?

As already said :

 

- Chaff rejection is mostly based on Doppler filtering. Thus, a radar in Doppler mode can reject chaffs quite easily in head / tail aspect because chaffs slow down quite fast after being ejected (large speed difference => consequent difference in the Dopppler shifts => easy filtering) but with more difficulties on a beam aspect (close radial speeds => small difference in the Doppler shift => difficult filtering)

 

- but chaff rejection is also dependent on the "geometry" (projection) : from the radar point of view, an aircraft seen on the beam will "move" away pretty fast from the cloud of chaffs (different blobs) and can be rapidly reacquired (if non manoeuvring...), by having the radar doing the same correction / interpolating the target trajectory as before.

On the other hand, if the target is on a head/tail aspect, the aircraft will appear for a short while "over"/"through" the cloud of chaffs, and that will make the job of a non-doppler radar more complicated.

 

Fighters radars tend not to use doppler filtering in -search- mode while looking up (not really needed due to not much ground clutter + no vulnerability to "beam"/"doppler notch manoeuver" + no detection / tracking range decrease).

Under these conditions, a radar could be more easily fooled by chaffs on a head / tail aspect than of the beam.

Once you put chaff into the air, you create a 'clutter' situation, and the radar goes into doppler mode. It's almost the same as if you were looking at the ground when you have chaff floating about. The radar can tell it's cluttered up without having to know wether it's looking up or down, but that might help too.

I agree. But my point was not to talk about ECCM in real life, but to share my idea about the way the tracking radars are implemented in the game : as if they were hybrids based on the "search" radar model and using a strictly defined look-up (strictly pulse mode => chaff mostly efficient on the front/rear) / look-down (strictly doppler mode => chaff mostly efficient on the beam, ) algorithm. :)

 

 

While looking down, it is the other way around : a search radar would be in "Doppler" mode and would be more easily deceived by a target using chaffs while on a beam than head/tail aspect.

 

A modern radar in "track" mode is behaving quite differently than in "search" mode : the chaff efficiency is -very- low, and the monopulse seeker of the AMRAAM is very unlikely to get fooled easily by that kind of counter measures.

I was wondering if ED wouldn't have worked on the "gameplay" by modeling the airborne "tracking" radars (and probably the behavior of SARH seekers) the same way than basic "search" radars ?

I really don't know what you mean here ... yes, search vs. track behavior is different in a number of ways for a number of reasons, but chaff rejection would be done better by an aircraft's radar typically (more processing power, more radar power, yadda)

I hope I was clearer this time :)

 

 

 

About the inertial guidance of the R27-TE : couldn'it be related to the way the missile is fired ?

Most of the Fox 2 are fired from a "rail" launcher : there is no "separation" / or really "ejection" from the aircraft.

But in the case of the R27-TE, the missile has to "clear" itself from the aircraft it's not a dogfight missile, it behaves like a heavy Fox 1.

Couldn't the inertial guidance be used for this purpose : move the missile far away (low) enough from the firing aircraft to make sure it doesn't collide after igniting its engine ?

 

About the seeker acquisition when the R27-TE is fired in "Mad Dog"

I think that an AIM-9 Sidewinder in uncaged mode is moving its seeker around, and that Lockon is only modeling the "boresight" mode where the seeker is not moving at all.

I'm wondering if it couldn't be the same with the R27-TE and the other russian Fox 2 : fire it in Mad Dog and it will acquire the first IR source that looks like a plane engine exhaust (gaz) within a certain angular limit, not determined by the seeker "proper" field of view, but by a larger cone determined by the scan rate of the seeker gyroscope etc...

 

No. It will lock onto to the FIRST IR source it sees ... be it the ground, a cloud, or the sun reflecting off of some lake below. This isn't modelled in LOMAC, and this is why maddogging heaters shouldn't be allowed, since the problems inherent in doing so RL are not tranlated to similar problems in the game.

No :) The first historical seekers were quite prone to lock anything because the technology available at this time only made possible to process IR signal with a wavelength higher than 2.5 microns, (lot of background clutter and high temperature needed for the IR source (tailpipe) in this band)

Most of the missile have been able to use for a while the 4 microns band ( emitted by the airframe located around the tailpipe and the exhaust gaz a bit cooled down). Considered the fact that the sun reflection on the clouds / water / ground is quite limited in this band, that there are not much propagation issues and the amount of optical and electronical filtering available in the seeker of a Fox 2 (not talking about IIR...), you should not expect such a missile to guide too easily on the clutter.

In contrary to what has been said, Fox 2 -can- filter out noise, but less efficiently than radars using doppler filtering... (a truck burning on the battlefield is a good example...).

 

If Fox 2 and maddog seems a strange association in the same sentence, it's probably due to the fact that :

- most of the Fox 2 are short range missiles (makes a "maddog" quite stupid : due to the fact that the kinetic range doesn't exceed that much the detection range).

- most of the Fox 2 doesn't have an inertial guidance system : that means that they just cannot go "straight" on a defined bearing/altitude by themselves.

- even though the Fox 2 can reject clutter, they will probably have the tendancy to lock by themselves some heat source on the ground while looking down toward the Earth.

- the seeker is very "sensible" and there would be a real need to define a higher "threshold" at which the missile should lock onto a supposed target while fired in Maddog. This level shoud definitly be far higher than the one used for "normal" use (IR seekers still tend to be able to lock onto a lot of things that are in no way related to a flying aircraft... :))

- the detection range being quite "short", it gives not that much time to the missile to correct its course (and a hard manoeuver means a lot of energy wasted).

- the risks of fratricid

 

Anyway, achieving a kill with a "maddoged" R27ET should be possible but should require far more luck and "Kentucky Windage" than what required right now and should in all cases be more considered as a low pk dirty trick / last ditch manoeuver than a standard method ... :)

 

One the missile is locked onto a source, an aircraft crossing in frton of it may well in fact be rejected as a decoy ...

Depends on the aircraft (full A/F, aspect...), depends on the heat source :)

 

 

Ciao :)

 

 

Hub.

 

 

 

PS : thanks Crusty ;) :)

PS : Sorry Pilotasso, but it seems that "Ze kreature ize alife" ;) :)

[GGTharos]

Ok. Without going into details, I think we are agreed then :D