TWS shot then STT it tracks

[Kartoffel]

I noticed that if you lock in TWS and shoot a missile and then in any phase of flight you change it to STT it starts to track, I haven't tried this without TWS yet but I would suspect that would work. Is this realistic?

[fixen]

I could see it being possible as long as the target stays within view of the sensor. But I wonder what the missile is programmed to do when launched without lock, or it even being possible.

[Chrinik]

Essentially all SARH missiles of a certain age are capable of doing that (theoretically even the FC ones, but....FC...) as they fly their initial approach with DL updates from the aircraft sensor, only turning on their seekers in terminal flight. So technically, TWS data would be all you need for a very rough launch and track, obviously not accurately.

[probad]

You're describing ARH not SARH though?

[Custard]

You're describing ARH not SARH though?

No he isn't, many SARH missiles like the R-27 are guided by datalink most of their flight.

[Davee]

No he isn't, many SARH missiles like the R-27 are guided by datalink most of their flight.

 

 

"only turning on their seekers in terminal flight"

 

Refers to ARH missiles.

[Zeus67]

I noticed that if you lock in TWS and shoot a missile and then in any phase of flight you change it to STT it starts to track, I haven't tried this without TWS yet but I would suspect that would work. Is this realistic?

 

I could see it being possible as long as the target stays within view of the sensor. But I wonder what the missile is programmed to do when launched without lock, or it even being possible.

 

SARH missiles in DCS only track when the radar is in STT. But if fired blind, like with the radar in RWS, or the contact is lost. They can reacquire the target as long as it remains within their seekers FOV, which is extremely narrow.

[Dudikoff]

SARH missiles in DCS only track when the radar is in STT. But if fired blind, like with the radar in RWS, or the contact is lost. They can reacquire the target as long as it remains within their seekers FOV, which is extremely narrow.

 

Which missiles are we talking about here? E.g. the Russian R-27 missiles (with monopulse seekers) are linked to a specific guidance channel frequency before launch and the radar will not reestablish it if the target lock is lost (I think the next frequency from the set would get chosen for the next missile). So the R-24/7 missiles most certainly cannot reacquire the target.

 

Older SARH missiles (with conical scan seekers, guided on CW reflection) had to be tuned to the CW transmitter frequency and required the seeker to be locked to the target before launch so being able to fire these without a proper radar guidance mode lock seems pretty wrong unless these French missiles used some different principles.

Edited June 5, 2016 by Dudikoff

[Chrinik]

"only turning on their seekers in terminal flight"

 

Refers to ARH missiles.

 

You obviously don´t know that SARH missiles ALSO have seekers...to see the reflection of Radar waves to guide in on.

 

It would be kinda hard for the missile to SEEK a target WITHOUT a SEEKER...

 

Those seekers are (depending on missile) NOT active until terminal flight to save power and thus weight for heavy batteries, because the missile is guided by INS/Datalink from the parent aircraft until terminal.

To prefice, you still need to maintain Radar lock...because YOU need to tell the missile where to go still...if the lock breaks, missile goes dumb because you don´t tell it where to go anymore.

 

Slightly off topic because AiM-7:

"The next version of the AIM-7 was the AIM-7M, whose main new feature was the new inverse monopulse seeker for look-down/shoot-down capability in a new WGU-6/B (later WGU-23/B) guidance section. There is no evidence of any Sparrow variants officially designated -7J/K/L (although the designation AIM-7J is sometimes associated with the AIM-7E license-built in Japan). Source [2] says that the suffix "M" was deliberately chosen to mean "monopulse", suggesting that suffixes J/K/L were indeed skipped. The monopulse seeker improves missile performance in low-altitude and ECM environments. Other new features of the AIM-7M are a digital computer (with software in EEPROM modules reprogrammable on the ground), an autopilot, and an active fuze. The autopilot enables the AIM-7M to fly optimized trajectories, with target illumination necessary only for mid-course and terminal guidance. The AIM-7M also has a new WDU-27/B blast-fragmentation warhead in a WAU-17/B warhead section. The first firing of a YAIM-7M occured in 1980, and the AIM-7M entered production in 1982."

 

Which apparently means you can launch the AiM-7M dumb and give it a Radar lock later. I think. But could refer to lofting trajectories, where the missile pops up to gain more range...with the seeker unable to see the target at all. Still, both would mean it is capable of "locking on" to a painted target AFTER launch.

 

Wiki sais about 530D:

"Guidance is by the mono-pulse AD26 CW Doppler semi-active seeker, which has improved ECCM capability, and improved capability against low-flying targets. The missile's guidance unit is also fitted with digital micro-processing, which enables the seeker to be reprogrammed against new threats."

 

Don´t know exactly what "reprogramming for new threats" means, but I took it meant it can update targets mid-flight...IE, reacquire.

 

Wiki on SARH guidance:

Maximum range is increased in SARH systems using navigation data in the homing vehicle to increase the travel distance before antenna tracking is needed for terminal guidance. Navigation relies on acceleration data, gyroscopic data, and global positioning data. This maximizes distance by minimizing corrective maneuvers that waste flight energy.

 

And here is a TLDR article for interested folks on missile guidance:

 

http://fas.org/man/dod-101/navy/docs/fun/part15.htm

 

Interesting parts would be to understand the difference between missile flight stages, control and homing guidance.

Almost no modern medium range missile has a single guidance method. Most have a combination of control guidance and homing guidance (for terminal accuracy)...

Edited June 5, 2016 by Chrinik

[Dudikoff]

You obviously don´t know that SARH missiles ALSO have seekers...to see the reflection of Radar waves to guide in on.

 

Those seekers are (depending on missile) NOT active until terminal flight to save power and thus weight for heavy batteries, because the missile is guided by INS/Datalink from the parent aircraft until terminal.

 

The SARH seekers are passive and are basically turned on all the time during the missile's flight (there might be some exceptions like e.g. the R-23 missile which had a delay of a few seconds after launch so the seeker is not confused by the airplane's own radar).

 

Which apparently means you can launch the AiM-7M dumb and give it a Radar lock later. I think. But could refer to lofting trajectories, where the missile pops up to gain more range...with the seeker unable to see the target at all. Still, both would mean it is capable of "locking on" to a painted target AFTER launch.

 

This is valid only for later SARH missiles with monopulse seekers and homed in on the monopulse radar reflections (rather than the CW transmitter) and which are receiving the mid-course updates encoded in the radar transmissions, but again, they are set for a specific target painting frequency before launch and if the lock is broken, this frequency is lost, at least in R-24/27 case. I'd expect a similar thing for the AIM-7M.

 

Don´t know exactly what "reprogramming for new threats" means, but I took it meant it can update targets mid-flight...IE, reacquire.

 

I don't know what this line is referring to (perhaps ECCM upgrade or something), but I don't see how you got the reacquiring capability confirmation out of it.

Edited June 5, 2016 by Dudikoff

[Chrinik]

But why do you need to turn on the seeker when you can use command guidance until terminal? That would just waste power and thus decrease range. I´m proposing that you don´t really need the seeker all that much for mid-course, when the missile carries INS guidance and Datalink. Considering the reflections off of the target are stronger the closer it gets to it, I don´t even think the seeker is all that accurate over 50km for example.

 

We are not talking about R-27s here. The russians may have done things differently judging by the fact that the TWS mode autolocks a target when in range. THEIR missiles might require STT locks and may work the way you described.

 

We are also not talking about reaquiring a lost lock. If a Radar Lock is lost at any point during the missiles flight, it gets NO updates anymore and goes stupid.

 

In essence, we are talking about wether or not you can lauch a modern SARH missile with TWS data and then later give it more accurate STT targeting...

 

Which I don´t think is wrong. You basically eyeball the thing towards a target with rough TWS data, giving it mid-course correction data based on your launch platform Radar information (your plane knows where the target is and tells the missile where to go), and then you give it an STT lock reflection to home in on.

 

It´s in principle the same way multiple Amraams are launched, with the difference being that you can´t engage multiple targets obviously, because your Radar can only STT lock a single target. But with the Amraam nobody questions that the Missile seemingly finds it´s intercept point by magic because it´s such an advanced missile...yeah right. INS missile guidance for mid-course correction has been around for a long time prior, I don´t see why it isn´t being used on these SARH missiles, and every article I´ve read about SARH missiles present in DCS states they use INS/Datalink for Mid-course and SARH for terminal guidance.

 

The Super 530D is from the late eighties, it isn´t a very old missile by DCS standards and it´s later then the Phoenix, which used the same INS/Datalink guidance until terminal we are talking about here.

An active seeker is only advantageous because you can launch multiple missiles at multiple targets.

 

I don´t understand why the same guidance methods somehow CAN´T be used on SARH missiles, apart from being limited to only one target per plane.

Edited June 5, 2016 by Chrinik

[Bacab]

But why do you need to turn on the seeker when you can use command guidance until terminal? That would just waste power.

 

We are not talking about R-27s here. The russians may have done things differently.

 

In essence, we are talking about wether or not you can lauch a modern SARH missile with TWS data and then later give it more accurate STT targeting...

 

Which I don´t think is wrong. You basically eyeball the thing towards a target with rough TWS data, giving it mid-course correction data based on your Radar information, and then you give it an STT lock reflection to home in on.

 

It´s in principle the same way multiple Amraams are launched, with the difference being that you can´t engage multiple targets obviously, because your Radar can only STT lock a single target. But with the Amraam nobody questions that the Missile seemingly finds it´s intercept point by magic because it´s such an advanced missile...yeah right. INS missile guidance has been around for ever, I don´t see why it isn´t being used on SARH missiles, and every article I´ve read about SARH missiles present in DCS states they use INS/Datalink for Mid-course and SARH for terminal guidance.

 

The Super 530D is from the late eighties, it isn´t a very old missile by DCS standards.

I don't think the Super 530D was fitted with an INS unit so even if the plane had been able to send data to the missile it would have been useless because neither the missile or the plane know where the missile is.

That's why it rely only on its seeker to guide and because of that you need to shoot it in PIC.

 

The reprogramation feature means the embedded software could be updated without changing the whole guidance section.

[Chrinik]

I don't think the Super 530D was fitted with an INS unit so even if the plane had been able to send data to the missile it would have been useless because neither the missile or the plane know where the missile is.

That's why it rely only on its seeker to guide and because of that you need to shoot it in PIC.

 

The reprogramation feature means the embedded software could be updated without changing the whole guidance section.

 

If it doesn´t have INS and only uses the seeker then it´s unrealistic behaviour in it´s current form.

[Dudikoff]

But why do you need to turn on the seeker when you can use command guidance until terminal? That would just waste power and thus decrease range. I´m proposing that you don´t really need the seeker all that much for mid-course, when the missile carries INS guidance and Datalink. Considering the reflections off of the target are stronger the closer it gets to it, I don´t even think the seeker is all that accurate over 50km for example.

 

Again, the seeker is passive, so it practically doesn't "waste" power. For the non-datalinked missiles, it's obviously on from the start as it cannot be launched without a seeker lock. For the datalinked missiles (monopulse seekers guided to monopulse radar reflections), it's on because you don't know at which range it can detect the reflected signal and lock to it. Those are INS guided until the seeker starts receiving radar reflections after which the seeker takes over.

 

We are not talking about R-27s here. The russians may have done things differently judging by the fact that the TWS mode autolocks a target when in range. THEIR missiles might require STT locks and may work the way you described.

 

What missiles are you talking about then? Some imaginary missiles which would fit how you imagine these things work like? AFAIK, all the SARH missiles require an STT lock before launch is authorized (which is a CW lock for the older SARH missiles). If you have some actual data which proves otherwise, post it, but there's little need for reinventing hot water here as the SARH missiles were discussed already on the forums many times, so I suggest you search for these older threads.

Edited June 5, 2016 by Dudikoff

[Azrayen]

Guys, let's put this at rest, shall we? ;)

- the M 2000C doesn't have aircraft-missile datalink; this was introduced with the M 2000-5F (by the way, via specific pointy antenna leading edge of the fin, not RDY radar)

- the current ability (in DCS) to shoot a S-530D +/- regardless of radar condition is simply a "default" mode (with no specific check implemented, you press the trigger, away the missile goes). I'm sure it's not meant to stay like this for long.