R/S530F Interaction with RWR

[Get_Lo]

R and S530F missiles are peculiar to DCS in that they are not guided by CW illumination, but rather by the steady pulse of the F1s radar. the S530F guides on the exact same 660hz frequency that the radar scans and tracks on. does this mean there will be no launch warning in the target aircraft when the S530F is fired? The S530F and R530F are both LOBL (lock on before launch) which means selecting the weapons will also set the frequency of the radar (to 2000hz in the case of the R530, and unchanged in the case of the S530F) and as previously stated, there is no CW illumination taking place for the hostile RWR to detect.
Maybe someone is knowledgeable on the subject? is this behavior modeled in DCS or is it simplified to a level that the RWR just "knows" when a missile is in the air?

[Northstar98]

IRL - not sure, if the Super 530F guides on the exact same frequency and pulse characteristics (PRF etc) the radar scans and tracks on then I don't see how it would be able to distinguish track from launch.

For the R.530 EM, it should be able to generate a launch warning by the frequency change - you don't necessarily need CW illumination to trigger a launch warning.

 

In DCS though? Likely the RWR just knows what state the radar is in. Everything EW is very simplified in DCS.

[MYSE1234]

@Get_Lo Do you have any public documents regarding this? I'm interested in modelling it slightly more realistically for the AJS37's RWR.

[Get_Lo]

3 hours ago, MYSE1234 said:

@Get_Lo Do you have any public documents regarding this? I'm interested in modelling it slightly more realistically for the AJS37's RWR.

unfortunately I dont have any documents on hand explains this particular interaction between radar and RWR. best I can tell from asking people who know what they're talking about, as long as you have a monopulse missile seeker that tracks on normal radar pulses and there is no shift in frequency between tracking and firing, the RWR should be unable to distinguish the two. Im not sure if we have ever had this combination in DCS before, I really hope Aerges models this behavior. 

 

4 hours ago, Northstar98 said:

IRL - not sure, if the Super 530F guides on the exact same frequency and pulse characteristics (PRF etc) the radar scans and tracks on then I don't see how it would be able to distinguish track from launch.

For the R.530 EM, it should be able to generate a launch warning by the frequency change - you don't necessarily need CW illumination to trigger a launch warning.

 

In DCS though? Likely the RWR just knows what state the radar is in. Everything EW is very simplified in DCS.

well some of the search modes in the F1 operate in the 2000hz range at low alt, and they all should if you have the missile selected. theoretically if an RWR detects these 2000hz emissions as a launch, then it should also treat a 2000hz track as a launch and trigger warnings for the hostile pilot, regardless if the missile has been shot or not.

[Northstar98]

10 minutes ago, Get_Lo said:

well some of the search modes in the F1 operate in the 2000hz range at low alt, and they all should if you have the missile selected. theoretically if an RWR detects these 2000hz emissions as a launch, then it should also treat a 2000hz track as a launch and trigger warnings for the hostile pilot, regardless if the missile has been shot or not.

Firstly, something I forgot to ask (though I guess it's obvious but I wanted to make sure), is the 660/2000 Hz thing the PRF?

And secondly, if it searches at the 2000 Hz PRF too then provided everything else is the same it should only be able to distinguish between search and track (purely by determining if the radar is staring at you or not). But if all the characteristics are the same I'm not sure how you'd discern track from launch.

My guess (barge full of salt) is that RWRs wouldn't trigger a launch warning at all (owing purely to false alarm rate) but that's just my guess - I haven't got much of an idea how real systems would react.

Edited July 17, 2022 by Northstar98

[MYSE1234]

12 minutes ago, Get_Lo said:

unfortunately I don't have any documents on hand explains this particular interaction between radar and RWR.

I'm more interested in how the radar itself works when tracking a target, not the radar/RWR interaction itself.

[Get_Lo]

9 minutes ago, MYSE1234 said:

I'm more interested in how the radar itself works when tracking a target, not the radar/RWR interaction itself.

oh, yes I can get that for you. One moment ill edit this message. I hope this is what youre looking for, anything else I can probably also find.

Edited July 17, 2022 by Get_Lo

[Get_Lo]

15 minutes ago, Northstar98 said:

Firstly, something I forgot to ask (though I guess it's obvious but I wanted to make sure), is the 660/2000 Hz thing the PRF?

And secondly, if it searches at the 2000 Hz PRF too then provided everything else is the same it should only be able to distinguish between search and track (purely by determining if the radar is staring at you or not). But if all the characteristics are the same I'm not sure how you'd discern track from launch.

My guess (barge full of salt) is that RWRs wouldn't trigger a launch warning at all (owing purely to false alarm rate) but that's just my guess - I haven't got much of an idea how real systems would react.

 

Indeed it is the PRF, the missile is LOBL so we know that it tracks on this frequency as well as proven by the document above.

[Harlikwin]

5 hours ago, Get_Lo said:

unfortunately I dont have any documents on hand explains this particular interaction between radar and RWR. best I can tell from asking people who know what they're talking about, as long as you have a monopulse missile seeker that tracks on normal radar pulses and there is no shift in frequency between tracking and firing, the RWR should be unable to distinguish the two. Im not sure if we have ever had this combination in DCS before, I really hope Aerges models this behavior. 

 

well some of the search modes in the F1 operate in the 2000hz range at low alt, and they all should if you have the missile selected. theoretically if an RWR detects these 2000hz emissions as a launch, then it should also treat a 2000hz track as a launch and trigger warnings for the hostile pilot, regardless if the missile has been shot or not.

 

I have some serious doubts that the original 530 was actually a monopulse seeker given its development date. The 530D for sure was, and I'm not really confident even the 530F was a monopulse seeker. 

[Get_Lo]

1 hour ago, Harlikwin said:

 

I have some serious doubts that the original 530 was actually a monopulse seeker given its development date. The 530D for sure was, and I'm not really confident even the 530F was a monopulse seeker. 

old RAAF R530K manual said something about the R530K being monopulse I believe, but as for S530F it definitely was. and I must clarify, this is more about the tracking type being "pulse" rather than the seeker being monopulse, as all that has to do with is the accuracy of the missile and has little to do with the type of RWR emission the hostile RWR would be detecting, as the missile is not emitting anything. Confusion might come from that the 530F was different to the 530D in that the 530D was CW PD guidance, where as the 530F was just pulse guidance as the Cyrano IV was found unfit for shoot-down interception, therefor no CW illuminator was fitted to the radar and the 530F just relied on pulse guidance like the R530 before it. however the seeker was a monopulse design, just no CW guidance.

chrome-extension://efaidnbmnnnibpcajpcglclefindmkaj/https://www.eurosae.com/wp-content/uploads/2017/09/R_Carpentier_Missiles_tactiques.pdf

"Les autodirecteurs (Super AD 26) pour Super 530 F et D représentent, comme leurs missiles, les solutions matures pour l’air-air d’interception en mode semiactif. Ce sont des autodirecteurs monopulses avec la technologie des années 1970, qui pèsent 30 kg (avec le gyroscope) ; par rapport à l’AD 26, la portée est nettement augmentée, en particulier grâce à l’antenne de diamètre plus important. Comme pour le Magic, la stabilisation de l’antenne est assurée à l’aide d’un gyroscope séparé (ce qui évite la tête gyroscopique). Le radôme, allongé d’un facteur 2, crée des difficultés pour l’autodirecteur (aberrations), contrairement à celui de l’AD 26 (hémisphérique) ; mais ce choix a permis une réduction de la traînée. "

Translation:

"The seekers (Super AD 26) for Super 530 F and D represent, like their missiles, mature solutions for air-to-air interception in semi-active mode. These are monopulse seekers with 1970s technology, which weigh 30 kg (with the gyroscope); compared to the AD 26, the range is significantly increased, in particular thanks to the larger diameter antenna. As with the Magic, antenna stabilization is provided using a separate gyro (thus avoiding the gyro head). The radome, lengthened by a factor of 2, creates difficulties for the seeker (aberrations), unlike that of the AD 26 (hemispherical); but this choice allowed a reduction in drag."

 

Edited July 17, 2022 by Get_Lo

[IvanK]

Cyrano II in Mirage IIIO/E was in Track (STT) a Monopulse radar.

Edited July 17, 2022 by IvanK

[Get_Lo]

1 hour ago, IvanK said:

Cyrano II in Mirage IIIO/E was in Track (STT) a Monopulse radar.

 

Always nice to hear from the real deal, thanks for the clarification. so I assume the R530 was a monopulse missile? 

[IvanK]

The Monopluse side of things as far as I recall was only used for the tracking of the target. Essentially by use of a  2 things called the "Magic T" and the "folded T".  The Magic T divided the received pulse into 2 quadrants and could then determine precisely within the beam the targets exact elevation position. The Folded T did the same simultaneously in elevation ... all happening within a single return pulse.  This just allowed very fine angular position information to be determined in a single pulse which was then used to ensure the range gate stayed with the target. It was very much better against range gate stealers than say Conscan trackers used in typical US radars of the same vintage.

The R530 just needed the RF to home on and (again as far as I recall) wasn't really a monopulse per see being a passive seeker. It was a cumbersome thing to use with an unbelievably low Pk. There was an agonizing 1-4 secs delay after lock on during which time the radar and and the missile synced frequencies (there were 10 available and randomized) and ensured the seeker wasn't masked by the aircraft itself (could be an issue as in the Mirage III it was only carried on the centreline). After this 1-4 secs delay the missile was considered viable. This delay was a serious operational limitation against High speed targets in front quarter intercepts.

To get the best out of the Cyrano II (and I don't see why the IV is any different) required almost continual attention to manual Gain control coupled with Screen intensity and target aging and Antenna elevation and of course each aeroplanes radar performance and set up was different.

Edited July 18, 2022 by IvanK

[Harlikwin]

21 hours ago, Get_Lo said:

old RAAF R530K manual said something about the R530K being monopulse I believe, but as for S530F it definitely was. and I must clarify, this is more about the tracking type being "pulse" rather than the seeker being monopulse, as all that has to do with is the accuracy of the missile and has little to do with the type of RWR emission the hostile RWR would be detecting, as the missile is not emitting anything. Confusion might come from that the 530F was different to the 530D in that the 530D was CW PD guidance, where as the 530F was just pulse guidance as the Cyrano IV was found unfit for shoot-down interception, therefor no CW illuminator was fitted to the radar and the 530F just relied on pulse guidance like the R530 before it. however the seeker was a monopulse design, just no CW guidance.

chrome-extension://efaidnbmnnnibpcajpcglclefindmkaj/https://www.eurosae.com/wp-content/uploads/2017/09/R_Carpentier_Missiles_tactiques.pdf

"The seekers (Super AD 26) for Super 530 F and D represent, like their missiles, the mature solutions for air-to-air interception in semiactive mode. They are monopulse seekers with 1970s technology, which weigh 30 kg (with the gyroscope); compared to the AD 26, the range is significantly increased, in particular thanks to the larger diameter antenna. As with the Magic, the stabilization of the antenna is ensured at the using a separate gyroscope (which avoids the gyroscopic head) The radome, lengthened by a factor of 2, creates difficulties for the seeker (aberrations), unlike that of the AD 26 (hemispherical); but this choice allowed for a reduction in drag."

Translation:

"The seekers (Super AD 26) for Super 530 F and D represent, like their missiles, mature solutions for air-to-air interception in semi-active mode. These are monopulse seekers with 1970s technology, which weigh 30 kg (with the gyroscope); compared to the AD 26, the range is significantly increased, in particular thanks to the larger diameter antenna. As with the Magic, antenna stabilization is provided using a separate gyro (thus avoiding the gyro head). The radome, lengthened by a factor of 2, creates difficulties for the seeker (aberrations), unlike that of the AD 26 (hemispherical); but this choice allowed a reduction in drag."

 

 

Well I suppose that settles it. I guess not that surprising given the R23 also used a monopulse seeker head. I guess the main issue for sparrow was miniaturizing it all.

 

 

[mettschnitte]

There is a mechanic used with the F-14, aim-54 and PD-STT that could be applied. When the missile is launched, the radar switches from a ~50% duty cycle to a full 100% duty cycle radar pulse. It is called Pulse Doppler Illumination or PDI. This drastically increases the energy recieved by the enemy RWR. Although frequency did not change, the hostile can detect your missile launch.

 

might apply here idk just my 2c

[Harlikwin]

15 hours ago, IvanK said:

The Monopluse side of things as far as I recall was only used for the tracking of the target. Essentially by use of a  2 things called the "Magic T" and the "folded T".  The Magic T divided the received pulse into 2 quadrants and could then determine precisely within the beam the targets exact elevation position. The Folded T did the same simultaneously in elevation ... all happening within a single return pulse.  This just allowed very fine angular position information to be determined in a single pulse which was then used to ensure the range gate stayed with the target. It was very much better against range gate stealers than say Conscan trackers used in typical US radars of the same vintage.

The R530 just needed the RF to home on and (again as far as I recall) wasn't really a monopulse per see being a passive seeker. It was a cumbersome thing to use with an unbelievably low Pk. There was an agonizing 1-4 secs delay after lock on during which time the radar and and the missile synced frequencies (there were 10 available and randomized) and ensured the seeker wasn't masked by the aircraft itself (could be an issue as in the Mirage III it was only carried on the centreline). After this 1-4 secs delay the missile was considered viable. This delay was a serious operational limitation against High speed targets in front quarter intercepts.

To get the best out of the Cyrano II (and I don't see why the IV is any different) required almost continual attention to manual Gain control coupled with Screen intensity and target aging and Antenna elevation and of course each aeroplanes radar performance and set up was different.

 

Are you talking about the radar here or the 530 missile seeker. Also anyone got pictures of the 530 missile seeker antenna? Should be easy to tell if its just con-scan or an actual monopulse that way. 

Edited July 18, 2022 by Harlikwin

[Vatikus]

[Harlikwin]

8 hours ago, Vatikus said:

ARGHHHH LOL, got one with the top cover off? So close... 

I.e. like this: This is an R-27 and you can clearly the 4 channels it uses for monopulse tracking

 

[Vatikus]

Haha, Sorry I do not have anything w/o that cap. Tho I had read that Super 530 was first monopulse, so I gather conical scan is the name of the game.

Edited July 19, 2022 by Vatikus

[Harlikwin]

49 minutes ago, Vatikus said:

Haha, Sorry I do not have anything w/o that cap. Tho I had read that Super 530 was first monopulse, so I gather conical scan is the name of the game.

 

Yeah I'd believe the Super530 could be monopulse, the 530D is for sure. And I recall that being touted as one of the improvements to the 530D though I can't find the source for that right now. 

[IvanK]

On 7/19/2022 at 7:33 AM, Harlikwin said:

Are you talking about the radar here or the 530 missile seeker. Also anyone got pictures of the 530 missile seeker antenna? Should be easy to tell if its just con-scan or an actual monopulse that way. 

 

Talking about the Radar. Pretty sure the R530 itself was NOT monopulse

[Harlikwin]

1 minute ago, IvanK said:

Talking about the Radar. Pretty sure the R530 itself was NOT monopulse

Thanks.

Any idea on the Super530F? 

[IvanK]

Nope only "expertise' I had was with R530 Radar variant.

[Harlikwin]

1 minute ago, IvanK said:

Nope only "expertise' I had was with R530 Radar variant.

Cool, thanks for your input.