Russian Threat Detector and SAR missiles???

[bSr.LCsta]

The detector continues to display the range of the bandit, and not the missile, like it does when an AR missile is fired.

Is this correctly modelled?

If so....what techniques other than noting distance/alt/speed/ect. at time of launch are used?

 

P.S. Sorry if this is a repost, my search function didnt work.

[GGTharos]

Yes, it is correctly modelled. The receiver is measuring radar power, not range ;)

[EvilBivol-1]

Additionally, remember that SARH missiles do not themselves send out energy, hence your RWR is blind to them and continues to display information on the primary radar threat, which is the launching fighter's radar, now in STT mode.

 

As for the techniques... the Russians have this wonderful term describing your best instrument when in deficient SA situations - its called the "Ass-meter". :D

[darkstarRAF]

Жопометр... damn, I'm just clearly surprised )))

SPO knows about launch of SAR missile only when enemy radar going into STT mode, so it doesn't know anything about missile itself.

[britgliderpilot]

Жопометр... damn, I'm just clearly surprised )))

SPO knows about launch of SAR missile only when enemy radar going into STT mode, so it doesn't know anything about missile itself.

 

In that case, is it realistic that RWRs can tell the difference between a lock and a missile launch/tracking?

[Alfa]

In that case, is it realistic that RWRs can tell the difference between a lock and a missile launch/tracking?

 

A missile launch(radar guided) can be detected because the "parent" radar starts transmitting midcourse guidance to the missile upon launch.

 

An ARH missile can only be detected by the RWR when it goes active - i.e. starts "illuminating" the target by itself.....a SARH missile never does so the RWR wont be able to detect it.

 

Cheers,

- JJ.

[Yellonet]

In that case, is it realistic that RWRs can tell the difference between a lock and a missile launch/tracking?

The aircrafts radar might be in a different mode once it's guiding a missile and the RWR can sense that, maybe? But then there should be a way of tricking your opponent that you have launced a missile even if you haven't...

[Yellonet]

A missile launch(radar guided) can be detected because the "parent" radar starts transmitting midcourse guidance to the missile upon launch.

How is such transmission different from a lock transmission... and is there some aircraft that can fool an enemy that they have launched a missile by transmitting "false info"?

[britgliderpilot]

A missile launch(radar guided) can be detected because the "parent" radar starts transmitting midcourse guidance to the missile upon launch.

 

An ARH missile can only be detected by the RWR when it goes active - i.e. starts "illuminating" the target by itself.....a SARH missile never does so the RWR wont be able to detect it.

 

Cheers,

- JJ.

 

Aha - so it detects the datalink, right?

 

Is it possible to tell that the datalink is aimed at you?

[Brit_Radar_Dude]

During the Vietnam War, the first US Wild Weasel aircraft were fitted with the WR-300 Launch Warning Receiver. It could detect the tell-tale power surge in the SA-2 guidance frequency that occured just prior to launch.

 

Of course our discussion here is about a2a SARH missiles and there is no seperate guidance and control frequency. But (just a guess) it may be that the enemy radar whilst in STT mode might have a short term power increase at launch. The missile receiver is not as big and sophisticated as the aircraft radar receiver so an increase in received reflected signal strength would help with guidance during the first few seconds of flight. Or there might be other tell-tale changes - PRF, etc.....

[Alfa]

 

...Of course our discussion here is about a2a SARH missiles and there is no seperate guidance and control frequency.

 

A datalink is indeed a case of a "seperate guidance and control frequency" ;)

 

Cheers,

- JJ.

[D-Scythe]

A missile launch(radar guided) can be detected because the "parent" radar starts transmitting midcourse guidance to the missile upon launch.

 

An ARH missile can only be detected by the RWR when it goes active - i.e. starts "illuminating" the target by itself.....a SARH missile never does so the RWR wont be able to detect it.

 

Cheers,

- JJ.

 

The AIM-7M doesn't have a data-link, IIRC. The AIM-7P and the AIM-120 does though.

 

Not sure about the R-27ER.

[Alfa]

Is it possible to tell that the datalink is aimed at you?

 

No :)

 

Cheers,

- JJ.

[Brit_Radar_Dude]

should be a way of tricking your opponent that you have launced a missile even if you haven't...

 

The NVA used to do precisely this against the USAF, they would go through 99% of the SA-2 launch sequence (which would trigger a launch alert in the aircraft) and then abort the launch. Often this could cause the aircraft to break off an attack.

[britgliderpilot]

No :)

 

Cheers,

- JJ.

 

So . . . . if a pair of bandits lock up you and your wingman, and fire a single SARH missile - both of you have to clench tightly and start worrying?

 

 

Is this something that ideally needs to be looked at in the quest for realistic RWR performance?

[Alfa]

The AIM-7M doesn't have a data-link, IIRC. The AIM-7P and the AIM-120 does though.

 

I am not too familiar with the AIM-7 versions - I know that early versions didnt use datalink, but were "beam riders" following the direction of the parent radar´s emission in STT mode, while later version(s) use an actual datalink.

 

Not sure about the R-27ER.

 

The R-27R/RE use datalink for midcourse guidance - just like the AIM-120 or R-77 :) .

 

Cheers,

- JJ.

[Alfa]

So . . . . if a pair of bandits lock up you and your wingman, and fire a single SARH missile - both of you have to clench tightly and start worrying?

 

As far as missile launches goes - yes.

 

But bare in mind that SARH missiles need STT(Single Target Track) support, so if your RWR first alerts you of a radar lock followed by a missile launch warning, then chances are that you are the target ;) . The reversed is more tricky - i.e. a launch warning without prior lock warning....because it could mean a launch of an ARH missile from TWS mode in which case you wouldnt know if the missile is aimed at you before the ARH seeker goes active :)

 

Cheers,

- JJ.

[Starlight]

During the Vietnam War, the first US Wild Weasel aircraft were fitted with the WR-300 Launch Warning Receiver. It could detect the tell-tale power surge in the SA-2 guidance frequency that occured just prior to launch.

 

Of course our discussion here is about a2a SARH missiles and there is no seperate guidance and control frequency. But (just a guess) it may be that the enemy radar whilst in STT mode might have a short term power increase at launch. The missile receiver is not as big and sophisticated as the aircraft radar receiver so an increase in received reflected signal strength would help with guidance during the first few seconds of flight. Or there might be other tell-tale changes - PRF, etc.....

 

sorry but older SARH needed CW (continuous-wave) target illumination, didn't they? I think that a CW "painting" is/was the signal that a SARH missile lauch was imminent. And CW illuminator is clearly different from pulse-doppler radar signal....

[Starlight]

During the Vietnam War, the first US Wild Weasel aircraft were fitted with the WR-300 Launch Warning Receiver. It could detect the tell-tale power surge in the SA-2 guidance frequency that occured just prior to launch

 

The NVA used to do precisely this against the USAF, they would go through 99% of the SA-2 launch sequence (which would trigger a launch alert in the aircraft) and then abort the launch. Often this could cause the aircraft to break off an attack.

 

The system described was one of the earliest RWR systems. It was a four vector antenna (named Vector IV) which gave basical threat direction info. It was also linked to a bright red "launch" light in the cockpit, soon dubbed by weasel pilots the "Oh, sh*t" light, guess why...

Anyway SA-2 launches were pretty easy to spot because they were huge missiles with a massive boost phase and a thick smoke trail. The only trick was to stay below any cloud deck, so it was possible to spot and outmaneuver any incoming SAM.

So I don't think that tactic worked that much. And also weasel packages were often patrolling before and during the attack, drawing the attention of AA batteries...

 

Anyway, even if todays SAMs and RHAWS are far more capable, that trick is still possible... RWRs intercept and decode signals to understand a *possible* launch. No warning system except MAWS (missile approach warning system) really detects a missile. They do only detect a shift in frequency, power or something else, yet the don't "see" the missile coming off its launch rail.

[GGTharos]

Even modern radars change emission pattern for guidance. In all cases where a radar switches to STT and a missile is fired, the waveform changes, AFAIK.

[Dudikoff]

A missile launch(radar guided) can be detected because the "parent" radar starts transmitting midcourse guidance to the missile upon launch.

 

An ARH missile can only be detected by the RWR when it goes active - i.e. starts "illuminating" the target by itself.....a SARH missile never does so the RWR wont be able to detect it.

 

Cheers,

- JJ.

 

But midcourse guidance was only used in R24/27 and AIM-7M onwards, IIRC. What about the earlier missiles? The launching aircraft started painting the target immediately after launch (not needed on later monopulse radars)?

 

And if the targeted aircraft can detect these midcourse updates, how can it not detect AIM-120 midcourse updates because it has them, too, IIRC, at least when the target changes aspect?