ALR-45/50 vs other RWRs - Page 2 - ED Forums
 


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Old 04-30-2019, 08:03 PM   #11
Dudikoff
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Quote:
Originally Posted by SgtPappy View Post
There was also someone here whose father said the RWRs were useless to the point that they had to mount their own in the cockpit facing different directions.
https://www.upi.com/Archives/1987/04...2670546667200/

I presume those were used because of newer SAM threats (like, newer than SA-2/3/6) showing up in the '80s?
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Old 05-01-2019, 11:53 AM   #12
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Quote:
Originally Posted by Dudikoff View Post
https://www.upi.com/Archives/1987/04...2670546667200/

I presume those were used because of newer SAM threats (like, newer than SA-2/3/6) showing up in the '80s?
Yep, there's a funny story about that. I know the A-6 in the early to mid 80's was equipped with an 'urgent' update to detect continuous-wave emitters (SA-6). It was a very basic detection system fitted to the glare shield. Two indicators (also fitted to the glare shield), one for the pilot and one for the B/N consisted of a set of 2 lights (green and amber), signalling whether the threat was on the plane's left or right side.
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Old 05-01-2019, 04:52 PM   #13
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Quote:
Originally Posted by Dudikoff View Post
https://www.upi.com/Archives/1987/04...2670546667200/

I presume those were used because of newer SAM threats (like, newer than SA-2/3/6) showing up in the '80s?
Yes, that could certainly be in an issue. And I would not blame the system or its designers for this since newer SAMs had to be programmed in and could not be as easily added to the system database as easily as I would presume it was by the time of the Gulf War.

It would still be nice to hear what other limitations/capabilities a RIO would have when concerning the RWR. Perhaps I will have to wait for the F-14A!

Quote:
Originally Posted by Blaze1 View Post
Yep, there's a funny story about that. I know the A-6 in the early to mid 80's was equipped with an 'urgent' update to detect continuous-wave emitters (SA-6). It was a very basic detection system fitted to the glare shield. Two indicators (also fitted to the glare shield), one for the pilot and one for the B/N consisted of a set of 2 lights (green and amber), signalling whether the threat was on the plane's left or right side.
This is how I understood it for the F-14's as well. Rudimentary indeed - which is why I have doubts about the RWR design.

Last edited by SgtPappy; 05-01-2019 at 04:54 PM.
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Old 05-01-2019, 10:13 PM   #14
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Quote:
Originally Posted by Dudikoff View Post
https://www.upi.com/Archives/1987/04...2670546667200/

I presume those were used because of newer SAM threats (like, newer than SA-2/3/6) showing up in the '80s?
you mean 70s?
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Old 05-05-2019, 06:28 PM   #15
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Do we have any local F-14 crew members who can comment more on the RWR systems?

I wonder if the Gulf of Sidra incident F-14's could detect the MiG-23 radars.
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Old 03-31-2020, 09:04 AM   #16
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Apologies for the late reply SgtPappy. I'll try to answer your PM in this thread if that's okay, but I don't really have much to add unfortunately.

My understanding is that the 'fuzz-buster' was specifically designed to pick up continuous wave illuminations, particularly the SA-6. The ALR-45/50 could detect the SA-2 & SA-3 etc. The ALR-45/50 was better than the ALR-25/27 and was equipped to handle an expanded frequency range (2 - 15.5 GHz). Note there are different versions of the ALR-45 (I'm sure you're well aware) and although there are similarities, I'm thinking more of the ALR-45D. The -45F was a digital/semi-digital variant prior to the advent of the ALR-67 I think.
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Old 03-31-2020, 11:33 AM   #17
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Hi Pappy, our RWR is a very realistic recreation of the F-14s rwr and behaves somewhat different than the RWRs you might be used to from other modules (without wanting to comment on their accuracy or reliability etc). Here is a summary of how our RWR is done, which will hopefully shed a bit more light on the subject for you:

This is not necessarily in direct reply to your question anymore, but please check out this overview written by our Grover, who designed the RWR:

The procedures/logic:

- Four sensors/antennas for the radar bands of tracking radars and airborne radars.
- Each antenna FOV is ~180° (or slightly more), and almost a perfect cone.
- The sensitivity at the edges of the cone is significantly lower than in the centre.
- When we get a message from DCS about being radiated, we simulate the signal it produces in each sensor. This includes factors such as the distance from the emitter (attenuation), the angle of arrival for each antenna, noise and other random signal amplitude fluctuations.
- From this moment we treat the signal as if we didn't know about the true parameters of the emitter and we only use the information from the emulated sensors (the previous step).
- We take the amplitude of the signal from each sensor, apply signal to noise cuts, combine and reconstruct the threat direction.
- Then, the reconstructed direction together with the signal signature is compared with the list of threats already being displayed. If we find one that correlates, we update its direction. Otherwise, we create a new threat and inform about it with the 'new guy' sound.

Some consequences of the procedure described above and a bunch of other features:

- No blind spots. However, if directly above or below, the threat has to be significantly closer (compared to the horizontal plane) to pass the SNR threshold.
- The direction is reconstructed in the 2D plane (the local aircraft frame of reference). For threats significantly outside that plane, their reconstructed direction may be inaccurate, and it usually shifts towards the 12, 3, 6, or 9 o'clock from the true position.
- The direction reconstruction accuracy improves as the distance from the emitter decreases. For the scan modes of the emitter (RWS/TWS), it's somewhere around 10-15° RMS.
- For the emitters in scan modes, a misassociation of a known-threat with a new signal can happen, and it occurs quite often, especially at long ranges.

It can result in:


a) ghosts (fake threats) appearing on the display - more probable if you or the threat do some manoeuvres;
b) merging a group of two or more threats of the same type into one threat. For example, a group of two Su-27 flying in close formation, both scanning with their radars, can appear on the screen as one '29' until they get closer.
- A malfunction/damage of one antenna/sensor doesn't make you completely blind in that direction, as the two adjacent antennas should still cover that area. However, the lack of that sensor makes the direction reconstruction procedure very innacurate, and it's very likely that some threats will be displaced by more than 90°.

Compared with the default RWR from DCS:

- An entirely new dedicated code, written from the grounds up.
- Antenna/electronics emulation.
- Threat reconstruction using the emulated signals.
- Enhance information obtained from the engine with more details (radar modes, missile guidance, noise etc.).
- No blind spots.
- Imperfect like a real device should be, and not a god's eye.
a) Some weak radars can appear late.
b) The directions will be inaccurate.
c) It will be harder to estimate the number of threats of one type when they form a group.
d) You'll receive launch warnings not only when you are the target of the missile. For example when flying in a close formation with your buddy; if an enemy launches a weapon such as AIM-7 or SA-6 at your buddy, you may receive a launch warning from that threat as well.
- Detailed failures/damages.

Another thing to consider with the RWR is that the antennas move with the control surfaces, which means that this will roll your RWR picture, just as when you are maneuvering the aicraft, the RWR picture will roll with it (and might display erronous contacts). This requires additional pilot skill to take RWR readings at the proper (level) moment in the maneuver in order to keep up an accurate SA as well as an eye to spot wrong readings in between.

I hope this helps with understanding the RWR better.
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Old 03-31-2020, 12:04 PM   #18
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This level of detail should really be done for the other modules as well. Wonder if HB have an RWR API they could share with ED.
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Old 03-31-2020, 01:11 PM   #19
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I can tell so much about RWR from my own experience.

IRL they are pretty inaccurate copared to most DCS modules.
(thats why I love the F-14 RWR and even start to really like the Viggen RWR)

My dad said the old Torndo RWE (back in the 90's) was about +/-20, even 30 degrees.
That's only for azimuth. Not talking about showing an SA-2 where there really was an approach radar, etc.

There is pretty accurate eqipment as well though...

For the the fact that they turned off the RWR on the ships deck, totally understand that.
Metall everywhere, reflections on carrier, other A/C, loads of radio waves bouncing arround...
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Old 03-31-2020, 10:34 PM   #20
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Quote:
Originally Posted by IronMike View Post
Hi Pappy, our RWR is a very realistic recreation of the F-14s rwr and behaves somewhat different than the RWRs you might be used to from other modules (without wanting to comment on their accuracy or reliability etc). Here is a summary of how our RWR is done, which will hopefully shed a bit more light on the subject for you:

This is not necessarily in direct reply to your question anymore, but please check out this overview written by our Grover, who designed the RWR:

The procedures/logic:

- Four sensors/antennas for the radar bands of tracking radars and airborne radars.
- Each antenna FOV is ~180° (or slightly more), and almost a perfect cone.
- The sensitivity at the edges of the cone is significantly lower than in the centre.
- When we get a message from DCS about being radiated, we simulate the signal it produces in each sensor. This includes factors such as the distance from the emitter (attenuation), the angle of arrival for each antenna, noise and other random signal amplitude fluctuations.
- From this moment we treat the signal as if we didn't know about the true parameters of the emitter and we only use the information from the emulated sensors (the previous step).
- We take the amplitude of the signal from each sensor, apply signal to noise cuts, combine and reconstruct the threat direction.
- Then, the reconstructed direction together with the signal signature is compared with the list of threats already being displayed. If we find one that correlates, we update its direction. Otherwise, we create a new threat and inform about it with the 'new guy' sound.

Some consequences of the procedure described above and a bunch of other features:

- No blind spots. However, if directly above or below, the threat has to be significantly closer (compared to the horizontal plane) to pass the SNR threshold.
- The direction is reconstructed in the 2D plane (the local aircraft frame of reference). For threats significantly outside that plane, their reconstructed direction may be inaccurate, and it usually shifts towards the 12, 3, 6, or 9 o'clock from the true position.
- The direction reconstruction accuracy improves as the distance from the emitter decreases. For the scan modes of the emitter (RWS/TWS), it's somewhere around 10-15° RMS.
- For the emitters in scan modes, a misassociation of a known-threat with a new signal can happen, and it occurs quite often, especially at long ranges.

It can result in:


a) ghosts (fake threats) appearing on the display - more probable if you or the threat do some manoeuvres;
b) merging a group of two or more threats of the same type into one threat. For example, a group of two Su-27 flying in close formation, both scanning with their radars, can appear on the screen as one '29' until they get closer.
- A malfunction/damage of one antenna/sensor doesn't make you completely blind in that direction, as the two adjacent antennas should still cover that area. However, the lack of that sensor makes the direction reconstruction procedure very innacurate, and it's very likely that some threats will be displaced by more than 90°.

Compared with the default RWR from DCS:

- An entirely new dedicated code, written from the grounds up.
- Antenna/electronics emulation.
- Threat reconstruction using the emulated signals.
- Enhance information obtained from the engine with more details (radar modes, missile guidance, noise etc.).
- No blind spots.
- Imperfect like a real device should be, and not a god's eye.
a) Some weak radars can appear late.
b) The directions will be inaccurate.
c) It will be harder to estimate the number of threats of one type when they form a group.
d) You'll receive launch warnings not only when you are the target of the missile. For example when flying in a close formation with your buddy; if an enemy launches a weapon such as AIM-7 or SA-6 at your buddy, you may receive a launch warning from that threat as well.
- Detailed failures/damages.

Another thing to consider with the RWR is that the antennas move with the control surfaces, which means that this will roll your RWR picture, just as when you are maneuvering the aicraft, the RWR picture will roll with it (and might display erronous contacts). This requires additional pilot skill to take RWR readings at the proper (level) moment in the maneuver in order to keep up an accurate SA as well as an eye to spot wrong readings in between.

I hope this helps with understanding the RWR better.
That's pretty impressive IronMike!
The early 90's (at least) version of the ALR-67, was susceptible to multiple spikes from certain, individual emitter types, is this modelled?

I know it's a daunting task, that requires a lot of man power, costs etc and Heatblur has a good relationship with Eagle Dynamics I'm sure, but I'd love it if you guys created your own simulation, it would be extraordinary! Competition isn't a bad thing.
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