Update of R-27R/T/ER/ET guidance system with inertial/radio command update

[GGTharos]

He was 4nm from the MiG. Should he have flown straight into it and reduced his chances of survival if the missile was launched just 4 seconds later?

Bad example.

 

But at the same time, an iraqui MIG-29B (Capt. Jameel Sayhood) locked on "Rico" Rodriguez F-15, and he considered that a missile could be incoming, and he began defensive maneuvers.

[JunMcKill]

He was 4nm from the MiG. Should he have flown straight into it and reduced his chances of survival if the missile was launched just 4 seconds later?

Bad example.

 

Honestly, he saved, because the Iraqis only had R-60, if they had an R-73 at 4nm, kaput!

[GGTharos]

I don't think it can do 4nm on the deck against a maneuvering fighter, but most importantly I don't believe the seeker can handle it (any of that type of seeker, not just R-73). Just IMHO.

[Seaeagle]

I agree with you that a LOCK (STT) signal, should be a warning to the pilot and begin defensive maneuvers. But what is in discussion here is what you posted, whether the target RWR receives (or not), the missile launch warning. For example most F-15 in desert storm used AIM-7 (SARH) and the iraquies MIG-23MF and BN never had a clue of what was flying to them!

 

But that could be:

 

a). a limitation to older RWR systems of those particular aircraft.

 

b). RWR not in proper working order.

 

But at the same time, an iraqui MIG-29B locked on "Rico" Rodriguez F-15, and he considered that a missile could be incoming, and he began defensive maneuvers.

 

Yes but doing that may help to prevent/worsen the conditions for an enemy launch or at least buy you some precious extra seconds for evasion. In my opinion the above doesn't really prove that he couldn't detect a missile launch - only that he didn't wait for it :) .

 

However, aside from the ability to detect the start of radio command transmission, there is also the possibility that an RWR could issue a launch warning simply when the received signal strength(compared to stored parameters for the particular radar type) indicates that the enemy aircraft is close enough to launch missiles.

[JunMcKill]

I don't think it can do 4nm on the deck against a maneuvering fighter, but most importantly I don't believe the seeker can handle it (any of that type of seeker, not just R-73). Just IMHO.

 

The lock happened at 8000 feet in own Rodriguez words (26:00), and he received the lock not at 4nm but from 8 to 4 nm, it's not clear

 

Edited June 16, 2016 by JunMcKill

[JunMcKill]

But that could be:

 

a). a limitation to older RWR systems of those particular aircraft.

 

b). RWR not in proper working order.

 

 

 

Yes but doing that may help to prevent/worsen the conditions for an enemy launch or at least buy you some precious extra seconds for evasion. In my opinion the above doesn't really prove that he couldn't detect a missile launch - only that he didn't wait for it :) .

 

However, aside from the ability to detect the start of radio command transmission, there is also the possibility that an RWR could issue a launch warning simply when the received signal strength(compared to stored parameters for the particular radar type) indicates that the enemy aircraft is close enough to launch missiles.

 

The real deal is that we dont really know how it is with the SU-27 and their 90s radar (not the original N001), and the 90s soviet RWR (not the ones sold to 3rd world allied countries in the 80s).

 

For what I read, the radar of the german MIG-29G was not bad compared with F-16 and F-15, but the US interchange pilots found, was that the R-27R sucks in range (compared vs AMRAAM), and the IRSTS was so bad that they forgot it, and used only radar. The MIG-29 was in maneuverability between the F-16 and the F-15.

 

Source: http://foxtrotalpha.jalopnik.com/how-to-win-in-a-dogfight-stories-from-a-pilot-who-flew-1682723379

Edited June 16, 2016 by JunMcKill

[JunMcKill]

Mid course signals are generated when the missile is launched. There are no 'stealthy timings' or other fun stuff in these automated systems.

Likewise, there is no 'TWS tracking' which is what you seem to be describing - for SARH missiles, with a final switch to STT.

 

There's no tricky 'switching to terminal guidance' stuff - the STT signal is all the modern SARH missile needs to home in on.

You will get the lock signal because those weapon systems require a lock to launch the missile.

 

The only point of dispute is whether the RWR can pick up and process the M-Link and thus trigger a launch warning based on sensing STT with embedded M-Link.

 

In fact you lock to emit a narrow pulsed or continuous-wave in order to make the target reflects more, but suppose that you launch a R-27ER to a target 50km away, as you say, the missile radar seeker is small compared with the attacker receiver and will not catch the rebound emision until it close the distance to the target. Now, in this phase of the flight, the missile use INS, making corrections via radio commands and do not need the radar CW emisions (remember the missile is in the first stage, and is close to the launcher, and is not a beam riding missile with a radar receiver in the tail), the missile monopulse seeker is all the time on, ampliflying the incoming microwave energy reflected by the target until find it (or not), at the final stage the missile will be far from the emitter and the RF guidance is no longer necessary, the seeker is able to amplify and receive the target reflection and fly to destroy it. (correct me is Im wrong)

 

The only thing that the target RWR can detect is the change of the radar mode from a standard pulse emision to CW, but dont know if you were simply locked, or a missile is on the way, as is in DCS RWRs (all FC RWR aircafts have the same problem, you can detect all missile launchs, with the exception of the one launched by F-15 using TWS)

Edited June 16, 2016 by JunMcKill

[Seaeagle]

The real deal is that we dont really know how it is with the SU-27 and their 90s radar (not the original N001), and the 90s soviet RWR (not the ones sold to 3rd world allied countries in the 80s).

 

I really don't know what you mean by that. The Su-27's radar in the 90'ies is the same N001 as in the 80'ies(and RWR as well for that matter). Newer designs were developed in the latter part of the 80'ies(for expected induction in the 90'ies), but due to the collapse of the Soviet Union, they weren't fielded. Its only very recently that Su-27 variants in Russian service got an upgraded version of the N001 or an all new radar(Su-35S).

 

For what I read, the radar of the german MIG-29G was not bad compared with F-16 and F-15...

 

Not bad in terms of pure range capability, but generally more cumbersome to find targets with when operated without GCI assistance.

 

... but the US interchange pilots found, was that the R-27R sucks in range

 

Yes thats basically also what the German Luftwaffe pilots said - that it had a disappointingly short range, but performed well enough within its launch parameters.

 

(compared vs AMRAAM)

 

....which probably isn't all that surprising considering that it(AMRAAM) is a newer generation weapon :) .

[JunMcKill]

I really don't know what you mean by that. The Su-27's radar in the 90'ies is the same N001 as in the 80'ies(and RWR as well for that matter). Newer designs were developed in the latter part of the 80'ies(for expected induction in the 90'ies), but due to the collapse of the Soviet Union, they weren't fielded. Its only very recently that Su-27 variants in Russian service got an upgraded version of the N001 or an all new radar(Su-35S).

 

The N001 was during the early 1990s superceded in Russian Air Force production by the N011 planar array design used in the Su-27M. It remained in production for export Su-27SK aircraft delivered to China, Vietnam and other global clientèle's.

 

A series of incremental upgrades have been performed on the N001, primarily to improve reliability and provide additional modes. The N001V/N001VE have improved digital processing, with a Russian Baguette BCVM-486-6 processor, compatibility with the R-77 / RVV-AE Adder BVR missile, and a range of air to surface modes to support multirole operations and air to surface and anti-shipping munitions. The relationship between the N001VE/VEP is not unlike that between the APG-63 on the F-15C and APG-70 on the strike oriented F-15E.

 

Sources:

http://www.ausairpower.net/APA-Flanker-Radars.html#mozTocId228428

 

http://aerospace.boopidoo.com/philez/Su-15TM%20PICTURES%20&%20DOCS/Overscan's%20guide%20to%20Russian%20Military%20Avionics.htm

 

Anyway inside the missile_data.lua of DCS, all missile parameters are below the specs given in all published docs, mainly the Rmax (Raero) and the Max speed, including head to head encounter at 10k height and 900km/h, the ones at 10k-900km/h pursuit and head to head at 1k height - 900km/h

 

....which probably isn't all that surprising considering that it(AMRAAM) is a newer generation weapon

 

You're right, the AIM-120B deployment started in 1994 and the 120C in 1996

Edited June 17, 2016 by JunMcKill

[Seaeagle]

The N001 was during the early 1990s superceded in Russian Air Force production by the N011 planar array design used in the Su-27M.

 

..Newer designs were developed in the latter part of the 80'ies(for expected induction in the 90'ies), but due to the collapse of the Soviet Union, they weren't fielded.

 

;) .

 

The N011(developed by NiiP) never entered service in its original form(nor did the Su-27M). But a further developed version with phased array antenna(N011M "Bars") was installed in the Su-30MKI exported to India. The latest iteration of it - the "Irbis-E"- is the radar I was referring to in connection with the Su-35S.

 

It remained in production for export Su-27SK aircraft delivered to China, Vietnam and other global clientèle's.

 

It did not - the Su-27SK has the old "plain vanilla" N001, while some Su-30MK(export) variants have the upgraded N001VE and others the N011M "Bars".

 

A series of incremental upgrades have been performed on the N001, primarily to improve reliability and provide additional modes. The N001V/N001VE have improved digital processing, with a Russian Baguette BCVM-486-6 processor, compatibility with the R-77 / RVV-AE Adder BVR missile, and a range of air to surface modes to support multirole operations and air to surface and anti-shipping munitions. The relationship between the N001VE/VEP is not unlike that between the APG-63 on the F-15C and APG-70 on the strike oriented F-15E.

 

Pretty much correct :)

Edited June 17, 2016 by Seaeagle

[JunMcKill]

;) .

 

It did not - the Su-27SK has the old "plain vanilla" N001, while some Su-30MK(export) variants have the upgraded N001VE and others the N011M "Bars".

 

 

 

Pretty much correct :)

 

AFAIK, the Chinese J-11 was build from the SU-27SK model (Source: Famous Russian Aircraft Sukhoi Su-27 by Yefim Gordon)

 

Edited June 17, 2016 by JunMcKill

[Chrinik]

Guys...Radar IS a radio frequency...I thought we all knew it was an acronym for "radio detection and ranging", but apparently people think radios and radars are completely seperate.

 

GGTharos, if I take your list, and tweek it to what people are talking about:

 

Lock target (this has its own technical processes)

Command launch

Missiles are tuned (or may already be tuned)

Turn on missile battery

Launch missile

Missile now has some steering commands to point it at the target initlally

Rear antennas receive carrier radar signal to compare doppler, and possibly also receive the radio command signal, if any (note, same antenna)

 

Guidance stuff happens.

 

Seeker is activated and missile locks on target when in terminal range.

 

That´s why people are confused, it´s because they assume the above list to occur.

 

Without detailed information on the R-27R/ER operations, people will still guess. I´ve looked through this tread, but haven´t found(or overlooked) any link to a detailed description to the operations and steps the R-27R/ER goes through...

I can only find information on the old (read, Vietnam era) AiM-7s, which had no INS /Radiolink and required the seeker to lock on to the target BEFORE launch. So, wether or not this is still true for modern missiles is up for grabs, I´ve been trying to find meaningful data, but of course, it´s hard to come by.

[Seaeagle]

AFAIK, the Chinese J-11 was build from the SU-27SK model (Source: Famous Russian Aircraft Sukhoi Su-27 by Yefim Gordon)

 

Yes China initially bought a number(cannot remember how many) of Russian manufactured Su-27SK aircraft - with the contract they also got a license to produce the type domestically under the name "J-11".

[JunMcKill]

Guys...Radar IS a radio frequency...I thought we all knew it was an acronym for "radio detection and ranging", but apparently people think radios and radars are completely seperate.

 

I agree, this is not in discussion, the problem here is how it's guided the russian SARH missile while the target is far from the emiter, for the info we have available, the R-27ER, have a max launch range of 110km for a aircraft flying above 10,000 meters and 900km/h.

 

The SU-27 radar can lock a target at 50-60km away, it means the electromagnetic pulse have to travel this distance and return degraded by several factors, like the target RCS, weather conditions, etc. The R-27 receiver/seeker can cover only the width of the missile (about 9 inch, in the image the one of the left)

 

 

Agat AAM seekers. Left to right: 9B-1101K dual plane monopulse semi-active homing seeker used in R-27R1/ER1, 9B-1348E active radar homing seeker used in R-77 variants, and 9B-1103K active radar homing seeker for R-27EA (Agat).

 

In certain conditions the missile can be launched in override, HOJ mode, etc, while the seeker in not receiving the returning emision yet, but the aircraft have a firm lock on and the radar is already emiting in CW.

 

And the final question, how the target RWR knows that the CW emision is only a lock on him, and not a missile launch, as it's simulated in DCS right now.

Edited June 17, 2016 by JunMcKill

[Chrinik]

Well I´d assume anything that isn´t a Passively or Actively scanned array can´t really send a seperate update frequency to an airborne missle (let alone multiple) while still being a functioning Radar.

 

So the notion that the same antenna is used to both track and lock a target AND send data is beyond me entirely. It can only do one thing at a time. Flaming cliffs simulates RWRs rather basic...to assume their operation or features are exactly realistic is questionable at best.

 

I already heard the "missile launch warning" is a very simple system within DCS...so I don´t even know if an RWR typically CAN destinguish and warn about a launch. Got absolutely no information on what RWRs can really do.

Edited June 17, 2016 by Chrinik

[JunMcKill]

Well I´d assume anything that isn´t a Passively or Actively scanned array can´t really send a seperate update frequency to an airborne missle (let alone multiple) while still being a functioning Radar.

 

So the notion that the same antenna is used to both track and lock a target AND send data is beyond me entirely. It can only do one thing at a time. Flaming cliffs simulates RWRs rather basic...to assume their operation or features are exactly realistic is questionable at best.

 

 

It's possible, look the F-15 radar, in TWS can follow several targets and even guide four AIM-120 missiles to four differents targets at the same time.

 

And in the MIG-29S simulated in DCS is the N019M and I quote:

 

"N019M is an updated version, developed as a response to the compromise of the N-019 radar by a US spy. Tested from 1986, it entered limited production in 1991. Slightly lighter than the N-019 at 350kg. N019 has increased ECM resistance, new software, and a more advanced built-in monitoring system. A new Ts101M computer relieves the processor overload problems of the N019, more than doubling capacity to 400,000 operations per second whilst weighing less, just 19kg, and with doubled MTBF of 1000h compared to the 500h of the Ts100. N019M allows two targets to be engaged by active radar homing missiles simultaneously. Range increased slightly to 80km. Originally intended to be fitted to the existing MiG-29 fleet as an upgrade, about 22 aircraft with N019M are thought to have entered service with the VVS."

 

I already heard the "missile launch warning" is a very simple system within DCS...so I don´t even know if an RWR typically CAN destinguish and warn about a launch.

Edited June 17, 2016 by JunMcKill

[Chrinik]

It's possible, look the F-15 radar, in TWS can follow several targets and even guide four AIM-120 missiles to four differents targets at the same time.

 

That is a completely different system and still doesn´t answer the question.

TWS essentially is a computer interpreting the radar returns AS IT SWEEPS and keeps track of them, updating each time the Radar cone physically sweeps over the contact. These returns are then interpreted and kept track of by a computer that can interface with the weapons control system and give targeting data to the weapons.

 

But wether or not the signal to the missile is send BY the radar dish (unlikely but I don´t know as I am not a radio wave expert, of note would be: Frequency-division multiplexing), or a seperate antenna specifically for it (more likely, as aircraft already have multiple antennas for multiple radios, and antennas aren´t that complicated nor large)

 

I also assume it´s unadvisable to use the Radar antenna to transmit signals to a SARH Missile as the cone of the Radar is locked to a single point...making is very narrow in comparison to the full sweep. This means that anything outside that cone (any tracking missile) would not recieve updates and go stupid. This would effectively return them to being beamriders, which we went away from really fast and is not consistent with the behaviour of missiles both in DCS and outside, where they can happily leave the radar cone in order to intercept a high aspect target.

 

I still assume a seperate system is used for the datalink with the missile.

Edited June 18, 2016 by Chrinik

[*Rage*]

2) The first phase of the missile flight is done by intertial guidance with a radio-command update in the first stage, becoming semi-active on the final stage.,

 

it is true and implemented.

 

If true and implemented then we shouldnt see ERs going dead off the rails because of chaff at +30km range when it still isn't using its seeker for guidance.

 

I understand there are changes to the SARH missiles in 1.5.4 though. Is the above behaviour fixed/improved?

 

Thanks.

[Seaeagle]

 

Without detailed information on the R-27R/ER operations, people will still guess. I´ve looked through this tread, but haven´t found(or overlooked) any link to a detailed description to the operations and steps the R-27R/ER goes through...

 

Then look again :)

 

I can only find information on the old (read, Vietnam era) AiM-7s, which had no INS /Radiolink and required the seeker to lock on to the target BEFORE launch. So, wether or not this is still true for modern missiles is up for grabs

 

No it isn't - the R-27R is LOAL. It has an inertial navigation system with radio correction(datalink) for cruise stage and semi-active radar homing for terminal stage.

[GGTharos]

Just a small detail:

 

AIM-7's could not be locked on target on the rail. The radar would blind them.

 

They were launched with an initial steering command to point them at the target, after that they would lock on.

 

Without detailed information on the R-27R/ER operations, people will still guess. I´ve looked through this tread, but haven´t found(or overlooked) any link to a detailed description to the operations and steps the R-27R/ER goes through...

I can only find information on the old (read, Vietnam era) AiM-7s, which had no INS /Radiolink and required the seeker to lock on to the target BEFORE launch. So, wether or not this is still true for modern missiles is up for grabs, I´ve been trying to find meaningful data, but of course, it´s hard to come by.

[Chrinik]

Just a small detail:

 

AIM-7's could not be locked on target on the rail. The radar would blind them.

 

They were launched with an initial steering command to point them at the target, after that they would lock on.

 

 

I or my source, can´t find it right now, must have misinterpreted something. During vietnam, a full systems lock on took about 4 seconds after getting launch authorization, to feed information to the missile. The source I can´t find said something about the RIO locking the radar onto a bandit, and then getting a cue wether or not the seeker had aquired said target...

Edited June 18, 2016 by Chrinik

[Chrinik]

Then look again :)

 

 

 

No it isn't - the R-27R is LOAL. It has an inertial navigation system with radio correction(datalink) for cruise stage and semi-active radar homing for terminal stage.

 

Great...I wasn´t referring to that...I was referring to the exact steps, IN ORDER, that the missile goes through prior and post launch.

 

I could previously only find information on the very old Sparrows. Newer Sparrows essentially function completely differently then the old Vietnam Era ones and thus might have different processes.

 

And since you obviously know, please, point me to the exact rundown of all systems and steps, and their function, during the launch of an R-27ER, I´d love to see em, I don´t think I saw them in this post apart from GGTharos´s post, which wasn´t missile specific.

Edited June 18, 2016 by Chrinik

[GGTharos]

I or my source, can´t find it right now, must have misinterpreted something. During vietnam, a full systems lock on took about 4 seconds after getting launch authorization, to feed information to the missile. The source I can´t find said something about the RIO locking the radar onto a bandit, and then getting a cue wether or not the seeker had aquired said target...

Full system lock on includes tuning the missiles etc.

 

The way these missiles operate was week described in one of the documents shown by lunaticfringe - technical stuff, not pilot's descriptions.

 

Think about it - a rear station sparrow on a phantom locking onto an aircraft in front of your plane is physically impossible.

[GGTharos]

Great...I wasn´t referring to that...I was referring to the exact steps, IN ORDER, that the missile goes through prior and post launch.

 

I could previously only find information on the very old Sparrows. Newer Sparrows essentially function completely differently then the old Vietnam Era ones and thus might have different processes.

 

And since you obviously know, please, point me to the exact rundown of all systems and steps, and their function, during the launch of an R-27ER, I´d love to see em, I don´t think I saw them in this post apart from GGTharos´s post, which wasn´t missile specific.

To this I want to say that ED had a lot of knowledge about the 27 series, down to some diagrams for the eccm circuits for the export versions iirc.

[Chrinik]

Full system lock on includes tuning the missiles etc.

 

The way these missiles operate was week described in one of the documents shown by lunaticfringe - technical stuff, not pilot's descriptions.

 

Think about it - a rear station sparrow on a phantom locking onto an aircraft in front of your plane is physically impossible.

 

Yes, I see that now. As I said, I was misinterpreting a source from head I had read quite a time ago.

 

To this I want to say that ED had a lot of knowledge about the 27 series, down to some diagrams for the eccm circuits for the export versions iirc.

 

To this I want to say that people still argue their data is incorrect...

Refering to IASGATGs missile mod thread, in which he argued with a developer about their missiles performance in game.