RWR Launch Warning (SARH)

[Cmptohocah]

I have posted a similar question some years ago, but I don't think I have formulated it well that time, so:

 

When should an RWR stop giving a launch warning, when there is an inbound SARH missile, and why?

Edited June 16, 2020 by Cmptohocah
Typo

[randomTOTEN]

An RWR fundamentally is a radio receiver (my latest speculation is that it's basically a complicated ADF/ARK). As far as I can tell, it receives signals, converts them to an audible frequency, and transmits it to the pilot. It also has some sort of filters or a signal database to compare, and those systems illuminate the different lights.

 

I think a very basic answer to your question, is that it will stop providing the warning of a launch, when it stops receiving the radio signals which indicate a missile in flight.

[draconus]

Simply when enemy radar is no longer supporting the missile.

[Cmptohocah]

...

I think a very basic answer to your question, is that it will stop providing the warning of a launch, when it stops receiving the radio signals which indicate a missile in flight.

 

I am guessing this would then depend on the type of the signal being emitted by the launching platform. If this is true, I guess then it should be time based, since the platform that has launched has no idea if the missile is still tracking or not.

[Cmptohocah]

Simply when enemy radar is no longer supporting the missile.

 

When you say "supporting", you mean sending guidance info?

[Ironhand]

When you say "supporting", you mean sending guidance info?

Don’t know about D but, if I had made that statement, I would mean “until the radar dropped out of STT after the launch.”

[randomTOTEN]

If this is true, I guess then it should be time based, since the platform that has launched has no idea if the missile is still tracking or not.

I think that's a fair guess, but related to the systems of the launching aircraft, and not so much the RWR itself.

I bet it's related to the length of time the battery inside the missile is able to power the receiver antennae, guidance computer, and missile flight controls.:book:

[draconus]

Don’t know about D but, if I had made that statement, I would mean “until the radar dropped out of STT after the launch.”

That's correct :thumbup:

[Cmptohocah]

That's correct :thumbup:

If I understood correctly, this means that - theoretically - RWR should keep "buzzing" as long as there some sort of STT detected after the launch. Wether that be the same platform continuing the lock after the launch or a wingman - in a pair flight - having the target in STT even though the launching platform eventually lost the lock.

Am I understanding this right?

[Ironhand]

If I understood correctly, this means that - theoretically - RWR should keep "buzzing" as long as there some sort of STT detected after the launch. Wether that be the same platform continuing the lock after the launch or a wingman - in a pair flight - having the target in STT even though the launching platform eventually lost the lock.

Am I understanding this right?

 

Almost. It’s not the STT lock itself. It’s the lock after the launch. At launch, there’s a frequency shift and most likely other changes occurring. That’s what cues the launch detection on the RWR. If the wingman has you locked but hasn’t launched after lead’s STT has dropped, your RWR will drop into a lock tone.

[Motomouse]

When the missle is in the blind spots of the RWR no warning is given.

[draconus]

If I understood correctly, this means that - theoretically - RWR should keep "buzzing" as long as there some sort of STT detected after the launch. Wether that be the same platform continuing the lock after the launch or a wingman - in a pair flight - having the target in STT even though the launching platform eventually lost the lock.

Am I understanding this right?

 

Theoretically, if the signals were the same, same strenght and direction, your RWR wouldn't discern one from the other.

 

@Motomouse: FC3 has simplified RWR implementation. Some modules like F-14 have much more realistic RWR simulation with no such thing as blind spots.

Edited June 17, 2020 by draconus

[Ironhand]

Theoretically, if the signals were the same, same strenght and direction, your RWR wouldn't discern one from the other...

If the signals were the same. But they shouldn’t be. Each aircraft in the flight should be using slightly different frequencies to keep from interfering with one another for search and targeting. I would imagine that allows the RWR to differentiate among them.

Edited June 17, 2020 by Ironhand

[GGTharos]

I have posted a similar question some years ago, but I don't think I have formulated it well that time, so:

 

When should an RWR stop giving a launch warning, when there is an inbound SARH missile, and why?

 

Depends on the system that's attacking. In other words, DCS doesn't really simulate any of that. We have a simple warning mechanism, and frankly not sure we need the RL complications, especially since it means knowing exactly what all the systems detected by the RWR actually do. And we mostly don't know all that.

[Motomouse]

Thanks for RWR clarification, thought I am in the F-18 forum, sorry.

[pepin1234]

Depends on the system that's attacking. In other words, DCS doesn't really simulate any of that. We have a simple warning mechanism, and frankly not sure we need the RL complications, especially since it means knowing exactly what all the systems detected by the RWR actually do. And we mostly don't know all that.

 

I will take a screenshot of this post. You have been involved in several discussions telling the contrary against Russian hardware.

 

As in the real life you can set same missile guidance freq to an onboard radar in a pair of MiG-29 or to a pair of Buk Systems.

 

Also they can launch the missile to an intercept point and start the guidance a while after by the second unit with same Guidance freq, while the first launcher unit already change the position. Doing so you will never get a RWR launch on time to avoid been hit.

 

This tiny but deadly upgrade can make a big difference in DCS battlefield. Still waiting for this real life upgrade that never been done in DCS and that is a 70s Soviet tactic been in all guided radars. Obviously this is a downgrade for Russian side in the Sim.

Edited June 17, 2020 by pepin1234

[Seaeagle]

I have posted a similar question some years ago, but I don't think I have formulated it well that time, so:

 

When should an RWR stop giving a launch warning, when there is an inbound SARH missile, and why?

 

When support from the launching aircraft is broken.

 

Earlier radar/SARH systems(such as with early AIM-7 versions) employed a separate CW(Continuous Wave) transmitter to illuminate the target for the missile SARH seeker, so the launch warning would come when the RWR detected this waveform commencing - i.e. at the point of launching the missile.

 

The system used by the MiG-29(and Su-27)/R-27R/ER employ PD(Pulse Doppler) target illumination, where the radar switches its transmission frequency between target tracking and target illumination/radio correction for the missile. So in this case it would be this(alternating frequency) that triggers the RWR launch warning - i.e. again when the missile is launched.

 

The missile has a finite operation time(onboard power supply), so when this is exceeded, I guess the weapon's control system of the launching aircraft will stop supporting it.

[Seaeagle]

When the missle is in the blind spots of the RWR no warning is given.

 

Doesn't matter in the case of SARH missiles, as these don't emit anything themselves.

[Seaeagle]

Don’t know about D but, if I had made that statement, I would mean “until the radar dropped out of STT after the launch.”

 

That would be the case for a "lock warning" - not "launch warning" as the OP asked about.

[draconus]

That would be the case for a "lock warning" - not "launch warning" as the OP asked about.

You misunderstood. STT after launch changes signal (or adds another, like CW) which some RWR can discern. When this signal is no longer detected RWR stops the warning and that was the answer.

Edited June 19, 2020 by draconus

[Seaeagle]

You misunderstood. STT after launch changes signal (or adds another, like CW) which some RWR can discern. When this signal is no longer detected RWR stops the warning and that was the answer.

 

No mate I didn't misunderstand :) . You are right about the above, but my response was in regards to what Ironhand said; “until the radar dropped out of STT after the launch.” - i.e. that you don't need to drop out of STT in order for missile support to end and thus RWR no longer giving a "launch warning".

 

The "lock warning" on the other hand is associated with the radar tracking the target in STT mode regardless of whether a missile is launched or not.

[draconus]

No mate I didn't misunderstand :) . You are right about the above, but my response was in regards to what Ironhand said; “until the radar dropped out of STT after the launch.” - i.e. that you don't need to drop out of STT in order for missile support to end and thus RWR no longer giving a "launch warning".

I'd like to know about that time duration when launching platform stops supporting the missile if you mean that above. Is it preset for a particular missile and supporting radar?

[Seaeagle]

I'd like to know about that time duration when launching platform stops supporting the missile if you mean that above. Is it preset for a particular missile and supporting radar?

 

For the R-27R missile, the maximum time duration of inertial guidance/radio correction is 30 seconds, while IIRC the total time for powered flight is ~ 60 seconds.

 

Whether the launching platform can determine a "lost missile" prior to that - i.e. target/missile parameters, range/time duration I don't know, but at least there would be little reason to provide missile support beyond its max operating time.

[Cmptohocah]

I did some testing in DCS and the current behavior for SPO RWR (Russian version) is:

 

LA warning starts after the missile has been fired and persists until the radar lock is broken.

This kind of makes sense since I see no reason for the radar to get out of pulse mode - IMHO.

 

I didn't check the behavior of the NATO RWRs yet. This is next on my list, but I guess the results should be the same.

Edited June 20, 2020 by Cmptohocah
Correction

[draconus]

LA warning starts after the missile has been fired and persists until the radar lock is broken.

 

And if it keeps the lock does it stop after some time or when the missile is lost in DCS?