reported SA-5 launch detection logic

[Hog_driver]

I think this was already discussed sometime, somewhere, just want to be sure.

How exactly is an SA-5 missile launch detected?

I was flying an F-16 at 15,000 ft, got a search warning, then a track warning, which was ok.

But at a range of 49 NM I got a launch warning - but how was the launch detected, since the SA-5 is a SARH system with no command guidance channel (as far as I know, I'm not an SME)?

 

[Northstar98]

The SA-5 does have a missile downlink (i.e. from the missile to the radar), but I'm not sure what, if anything changes when the Square Pair goes from tracking a target to supporting a missile.

[Hog_driver]

I guess the KRO missile flight status signal was sent only if the missile lost the target.

Edited June 1, 2024 by Hog_driver

[okopanja]

Depending on the range SA-5 launches ither with proportional navigation or a loft. Loft is very steap and during this time the seaker does not see the target. During this phase there is no need to go into STT. After reaching certain altitude the missile will turn toward the target and radar will activate STT once it gets close eniugh.

This is why you do not get warning on launch itself.

[Hog_driver]

9 hours ago, okopanja said:

Depending on the range SA-5 launches ither with proportional navigation or a loft. Loft is very steap and during this time the seaker does not see the target. During this phase there is no need to go into STT. After reaching certain altitude the missile will turn toward the target and radar will activate STT once it gets close eniugh.

This is why you do not get warning on launch itself.

That's how I understand it, the problem is that I actually GOT the launch warning.

[falcon_120]

There some decisions on SAM game mechanics in general that are this way i suspect to make easier for players to survive, specifically there are several SAMs in DCS that i suspect will not provide a launch warning IRL just a search indication so SAMs are actually amazingly dangerous.

Some of these SAMs im mentioning should not give a launch warning are the SA10, Patriot, Aegis systems. Im sure im leaving out a lot more, but for these ive heard real cases in recent conflicts were aircraft have been shot down without taking evasive maneuvers even, which make me suspect they were not aware of a launch indication whatsoever.


Sent from my iPhone using Tapatalk

[Hog_driver]

1 minute ago, falcon_120 said:

There some decisions on SAM game mechanics in general that are this way i suspect to make easier for players to survive

Thanks, it makes sense. Which doesn't mean that I necessarily like those decisions  but I kind of can understand them from the gameplay point of view.

[draconus]

On 6/2/2024 at 10:55 AM, falcon_120 said:

There some decisions on SAM game mechanics in general that are this way i suspect to make easier for players to survive, specifically there are several SAMs in DCS that i suspect will not provide a launch warning IRL just a search indication...

You suspect? That'd be disgusting of ED to make such decision - it was probably just simplification due to current SAM code implementation. If you have RL info that the systems should not have detectable launches but they have in DCS it should be reported here: https://forum.dcs.world/forum/540-weapon-bugs/

[Hog_driver]

49 minutes ago, draconus said:

 If you have RL info that the systems should not have detectable launches but they have in DCS it should be reported here: https://forum.dcs.world/forum/540-weapon-bugs/

No RL info, it's just logic - you're almost 50 NM away, you've got no MAW (IIRC), you've been tracked and locked on for some time and the Gammon is a SARH system, no command signals are emitted after launch - so how is your RWR able to detect the launch? I guess the matter was discussed on the SAM simulator forum, many years ago.

[draconus]

19 minutes ago, Hog_driver said:

I guess the matter was discussed on the SAM simulator forum, many years ago.

If it was not reported here then it's irrelevant.

@Flappie are you aware of any reports with SAMs giving RWR launch warnings when they should not?

[Hog_driver]

5 minutes ago, draconus said:

If it was not reported here then it's irrelevant.

Yeah, I know. It was discussed because in one scenario, the target (SR-71) turned ECM on immediately after missile launch - but how did the pilot (or WSO) even know that the missile was airborne? It was agreed that the pilot must get a notification from an AWACS aircraft, and a delay was introduced.

[Flappie]

48 minutes ago, draconus said:

If it was not reported here then it's irrelevant.

@Flappie are you aware of any reports with SAMs giving RWR launch warnings when they should not?

Yes, there's one specifically related to the SA-5.

I'll bump the report right away.

[falcon_120]

You suspect? That'd be disgusting of ED to make such decision - it was probably just simplification due to current SAM code implementation. If you have RL info that the systems should not have detectable launches but they have in DCS it should be reported here: https://forum.dcs.world/forum/540-weapon-bugs/

Unfortunately i only have anecdotical evidence from war reports and pilots podcast from some of those systems (SA10, AEGIS and PATRIOT). So no bug report to be made without clear docs supporting this.

You are also right about that some of the current functioning could be very well caused by limited possibilities within the current SAM/EW/RWR implementation in DCS and this will be improved at due time.




Enviado desde mi ELE-L29 mediante Tapatalk

[_Hoss]

On 6/1/2024 at 1:38 PM, Hog_driver said:

I think this was already discussed sometime, somewhere, just want to be sure.

How exactly is an SA-5 missile launch detected?

I was flying an F-16 at 15,000 ft, got a search warning, then a track warning, which was ok.

But at a range of 49 NM I got a launch warning - but how was the launch detected, since the SA-5 is a SARH system with no command guidance channel (as far as I know, I'm not an SME)?

 

SARH missiles require tracking radar to acquire the target, and a more narrowly focused illuminator radar to "light up" the target for the missile to lock on to the radar return reflected off the target.^[5] The target must remain illuminated for the entire duration of the missile's flight. This could leave the launch aircraft vulnerable to counterattack, as well as give the target's electronic warning systems time to detect the attack and engage countermeasures. Because most SARH missiles require guidance during their entire flight, older radars are limited to one target per radar emitter at a time.

The F/A-18's AN/ALQ-126 Deception Repeater has a circuit card in it called a Pulse Density Demodulator. It looks at a specific area (window) of the received TTR (target tracking RADAR) signal. Once the missile launches and the booster falls off, it exposes an antenna, the TTR will start sending guidance pulses to the Missile. The PDD card sees this and knows the missile is in the air now because those pulses are moving quite nicely in our window, at this point we start transmitting deception pulses back to the TTR on a one-for-one basis. For each pulse that the 126 sees it will transmit a deception pulse at a higher amplitude to bury the actual return in noise. Remembering the 126 once moved from RCV to RPT at Fence In, will only transmit once the received signal strength exceeds a predetermined threshold, and will stop repeating when it exits that signal strength threshold on the way out. Most SAMs, Airborne TTRs, and DECM systems transmit at 1,000 watts or 60 dBm, as does the AN/ALQ-126A/B, and F/A-18 RADARS. For every +3 dBm, the signal strength doubles, for every -3 dBm it halves. Sense, On and Snap, Off (Repeater On/Off) is 29 and 39dBm.

Does that help?

My leg to stand on........

AT1(AW/SW) USN ret. 1977-1997

DECM Technician. AIMD/IM3/64C/61D (CV-64/CVN-65 w/VA-94/CVN-72) Seven WESTPACS

AN/ALR-45/50/45F/67 (Threat Receivers)

AN/ALQ-126A (A-6E, A-7E) AN/ALQ-126B (F/A-18C/D)  (Deception Repeaters)

AN/ALE-29/39/41 (Chaff Dispensers)

KIT/KIR-1A & KY-58 (COMSEC)

AN/DLQ-3B (Deceive Iranian F-14 AWG-9 RADAR)

AN/USM-406 DECM Sweep Cart. (Tests DECM suite in the aircraft)

2M Micro/Miniature Repair technician

I retired Apr. 30th of 97 and was hired by Boeing at NAS Lemoore, CA on May 19th of 97 to work in their Avionics Repair Facility in VFA-125's Hanger Mod... yeah... you can call it BARF.

While there, I worked on AN/APG-65/73 RADARS, FCES, FIRAMS, MSDRS, IFEI, EMD, UFC, ICS, CLIP, BADSA, ADC, ACNIP...etc..etc...etc. I retired from there on June 30, 2021. So, that's 44 years of working on USN Avionics systems. And I still don't think of myself as an SME.

Hoss

[Hog_driver]

8 minutes ago, _Hoss said:

The F/A-18's AN/ALQ-126 Deception Repeater has a circuit card in it called a Pulse Density Demodulator. It looks at a specific area (window) of the received TTR (target tracking RADAR) signal. Once the missile launches and the booster falls off, it exposes an antenna, the TTR will start sending guidance pulses to the Missile. The PDD card sees this and knows the missile is in the air now because those pulses are moving quite nicely in our window, at this point we start transmitting deception pulses back to the TTR on a one-for-one basis. For each pulse that the 126 sees it will transmit a deception pulse at a higher amplitude to bury the actual return in noise. Remembering the 126 once moved from RCV to RPT at Fence In, will only transmit once the received signal strength exceeds a predetermined threshold, and will stop repeating when it exits that signal strength threshold on the way out. Most SAMs, Airborne TTRs, and DECM systems transmit at 1,000 watts or 60 dBm, as does the AN/ALQ-126A/B, and F/A-18 RADARS. For every +3 dBm, the signal strength doubles, for every -3 dBm it halves. Sense, On and Snap, Off (Repeater On/Off) is 29 and 39dBm.

Does that help?

 

Interesting, thank you for you input. But I still haven't found any information on any guidance signals sent to the missile by any of the SA-5 system radars.