PIRATE modeling?

Only 7.5 km? That seems a bit short.

 

I would think that in clear skies the range would be much more than that, but I am also basing that assumption on ground operated laser rangefinders, like those you find on MBTs and such. I know a Leopard 2 can range out to 10 km with it's laser for example.

Its probably a less colimated beam to account for pointing errors. Also how does it deal with "confusing" (first/last) returns. You know like tank LRFs of that era.

Its probably a less colimated beam to account for pointing errors. Also how does it deal with "confusing" (first/last) returns. You know like tank LRFs of that era.

Well I'd assume the laser isn't used before the FLIR camera has actually acquired the target, hence I don't see the need for a wider beam.

Found this video:

Well I'd assume the laser isn't used before the FLIR camera has actually acquired the target, hence I don't see the need for a wider beam.

 

Found this video:

Pointing a laser at something small, and fast moving is rather challenging. I get that in theory it "just works" but IRL there are shittons of technical hurdles that have to be overcome. And at a guess the range of any laser based solution is going to be limited, and then there's the practical considerations of using a laser, like blinding the shit out people.

Pointing a laser at something small, and fast moving is rather challenging. I get that in theory it "just works" but IRL there are shittons of technical hurdles that have to be overcome. And at a guess the range of any laser based solution is going to be limited, and then there's the practical considerations of using a laser, like blinding the shit out people.

I don't doubt that, but with a good enough gyro stabilizer plus tracking system it can be done with amazing accuracy.

I don't doubt that, but with a good enough gyro stabilizer plus tracking system it can be done with amazing accuracy.

Yeah, but I have my doubts how good the one in pirate is, and how well it works when actually maneuvering. At short range its probably fine, long range thats the issue.

Yeah, but I have my doubts how good the one in pirate is, and how well it works when actually maneuvering. At short range its probably fine, long range thats the issue.

I actually don't think so as it only needs to be so good before imaging software can actively track as well, such as you've probably recently seen in US Navy footage of F/A-18's tracking unidentified objects off the eastern seaboard.

The optics, sensors, gyro stabilizer, laser & imaging software in PIRATE are all supposed to be state of the art, so I'm rather confident it can rangefind much further than 7.5 km. How much further? Not sure, we don't even have a source for the 7.5 km figure, and it's obviously going to vary a lot depending on the weather.

What we do know is that it can track a target up to 150 km away under certain circumstances, and usually in between 50-80 km. That says a lot about the capability of the optics & sensors alone.

Sources:

http://grupooesia.com/en/portfolio-productos-ingenieria/flir-irst/

https://www.defenseindustrydaily.com/files/2008_RAND_Pacific_View_Air_Combat_Briefing.pdf

https://www.bundesheer.at/truppendienst/ausgaben/artikel.php?id=807

There’s plenty of sources for OLS-27 laser range finder range, I just mis remembered, it seems to actually be 2.8km, this is not the only publication with that figure https://pdfs.semanticscholar.org/a59c/9025a7930f27793edaa26b7b4b97b6d7435d.pdf

About LASER accuracy:

The A400M DIRCM is able steer an approaching FOX2 away from it by pointing a LASER into the right spot of the sensor.

Don't ask me about the range, thats not public of course.

But a big turning Cargo plane (-> the senors are not very close to the aerodynmic center and/or CG and are turning well inside this axis system already)

and a small and fast tunring missile is good example how accurate systems can be.

About LASER accuracy:

 

The A400M DIRCM is able steer an approaching FOX2 away from it by pointing a LASER into the right spot of the sensor.

 

Don't ask me about the range, thats not public of course.

 

But a big turning Cargo plane (-> the senors are not very close to the aerodynmic center and/or CG and are turning well inside this axis system already)

and a small and fast tunring missile is good example how accurate systems can be.

Largely irrelevant, DIRCM are short range systems with moderately wide beamwidths to make sure they "hit". A few km range is fairly straightforward.

The issue with long range systems is that you have to deal with much much smaller angular effect pointing issues as range increases. The second thing is atmospheric issues, i.e. your target isn't exactly where the optics "think" he is.

Most specs I've seen on LRF's for this type of thing tend be about 10km +/-, for lasing ground targets (the ground is a BIG target, hard to miss), then its mainly laser power thats the issue. But those can have ranges of 10's of NM.

The third point is. Why in gods name use an ACTIVE system like a LRF to let the target know you are hunting him? When you have passive means to do all this anyway.

I actually don't think so as it only needs to be so good before imaging software can actively track as well, such as you've probably recently seen in US Navy footage of F/A-18's tracking unidentified objects off the eastern seaboard.

 

The optics, sensors, gyro stabilizer, laser & imaging software in PIRATE are all supposed to be state of the art, so I'm rather confident it can rangefind much further than 7.5 km. How much further? Not sure, we don't even have a source for the 7.5 km figure, and it's obviously going to vary a lot depending on the weather.

 

What we do know is that it can track a target up to 150 km away under certain circumstances, and usually in between 50-80 km. That says a lot about the capability of the optics & sensors alone.

 

Sources:

http://grupooesia.com/en/portfolio-productos-ingenieria/flir-irst/

https://www.defenseindustrydaily.com/files/2008_RAND_Pacific_View_Air_Combat_Briefing.pdf

https://www.bundesheer.at/truppendienst/ausgaben/artikel.php?id=807

See post above. The sensors can see that far, and track that far. But pointing a laser accurately that far is pretty hard, and TBH there are better (read passive) ways of getting enough range info to huck an fox3 with enough accuracy to get there and then turn its radar on for the terminal phase of the attack (or tbh stuff like dual IR/Radar seekers too).

In the context of DCS and what I'd like to see modeled, is actual thermal performance/tracking and issues in look down environments, and also atmospheric considerations, such as being blocked by clouds. And then the issues with target aspect and thermal state impacting detection ranges.

This is where it really depends on ED's core for atmospheric and thermal modeling. Probably the most important and eagerly awaited core changes as the sky and weather modeling is highly important for any decent sim, as well as its effect on various sensor suites.

The MiG-23 used the (TP-23ML) IRST and later versions used the (26SH1) IRST.

 

Now given that Raz is doing the modeling, I have no doubt it will FC3 level.

Wasn't aware the MiG-23 has/had IRST... make me want it even more. Just always wanted LNS/HB to make it...

Also, modern IRST's can use angle rate ranging, and other techniques like datalink baselines for range finding.

If something like the IRIS-T can have an internal database to compare it's picture to, a system like the PIRATE can have that even more. Basically, when the thing actually knows what it sees, it literally can triangulate the range with a little CPU power. The method worked well enough already in WWII, heck, even back in WWI without CPUs at all, submarine warfare heavily relied on that. If a brain can do that, it should be a stroll in the park for a modern computer system. And it'd be completely passive...

Found this video:

 

0:36 is reason enough to have that System IMHO... and as we've talked Raz already, it's a shame they decided not to model that on the Harrier...

If something like the IRIS-T can have an internal database to compare it's picture to, a system like the PIRATE can have that even more. Basically, when the thing actually knows what it sees, it literally can triangulate the range with a little CPU power. The method worked well enough already in WWII, heck, even back in WWI without CPUs at all, submarine warfare heavily relied on that. If a brain can do that, it should be a stroll in the park for a modern computer system. And it'd be completely passive...

Doing some awful back of the envelope math, if the opening of the IRST is ~20cm and it's operating at a few microns, its angular resolution should be in the ballpark of wavelength/diameter, or ~10^-6/10^-1 ~10^-5 radians.

The angular size of an aircraft with a wingspan of 10m at, say, 100km is in the order of 10/10^5 ~10^-5 radians, so in principle you resolve an aircraft even at very optimistic distances.

The tricky bit is that at that limit you are basically detecting pixel-size targets, so imaging is going to be tricky and distance measurements will be very hard (unless you can triangulate with datalink or something). Going by these estimates (which granted are insanely hand wavy), I think you can use angular size to reliably measure distance only at a 10km or so.

Doing some awful back of the envelope math, if the opening of the IRST is ~20cm and it's operating at a few microns, its angular resolution should be in the ballpark of wavelength/diameter, or ~10^-6/10^-1 ~10^-5 radians.

 

The angular size of an aircraft with a wingspan of 10m at, say, 100km is in the order of 10/10^5 ~10^-5 radians, so in principle you resolve an aircraft even at very optimistic distances.

 

The tricky bit is that at that limit you are basically detecting pixel-size targets, so imaging is going to be tricky and distance measurements will be very hard (unless you can triangulate with datalink or something). Going by these estimates (which granted are insanely hand wavy), I think you can use angular size to reliably measure distance only at a 10km or so.

Yeah at longer ranges you are basically looking at a pixel or a "few" pixels, depending on the optical system. The usual issue with long rage range finding is having enough rate change for it to be a reliable measurement over time, so for "hot or cold" targets it likely won't be at a very long range. At least if only measured from one sensor. This is where the F35 and its distributed aperture system has advantages.

This is where it really depends on ED's core for atmospheric and thermal modeling. Probably the most important and eagerly awaited core changes as the sky and weather modeling is highly important for any decent sim, as well as its effect on various sensor suites.

Yeah those are pretty important things for sensor modeling. Aside from the fact "weather" is important in general.

Wasn't aware the MiG-23 has/had IRST... make me want it even more. Just always wanted LNS/HB to make it...

Yup, I'm trying to find out more about it, and how it was used. The fact its mounted on the underside of the plane is a bit weird, but it hints at the fact it was there to back up the radar in look down situations, or perhaps look down tracking.

If something like the IRIS-T can have an internal database to compare it's picture to, a system like the PIRATE can have that even more. Basically, when the thing actually knows what it sees, it literally can triangulate the range with a little CPU power. The method worked well enough already in WWII, heck, even back in WWI without CPUs at all, submarine warfare heavily relied on that. If a brain can do that, it should be a stroll in the park for a modern computer system. And it'd be completely passive...

 

0:36 is reason enough to have that System IMHO... and as we've talked Raz already, it's a shame they decided not to model that on the Harrier...

Yeah that angle rate ranging is a bit more complex than the ww2 method, but broadly speaking yes, but there are limits to it when you are measuring very small angles.

And yeah, that vid looks like hotspot tracker/que system. But again for DCS reasons Razbam can't do it.

If it's anything like the IRST on US interceptors like the F4/8/101/102/104/106 (which is very likely), the Mig's IRST is there mostly as a backup for when the radar can't burn through jamming, and likely has a fairly limited range.

If it's anything like the IRST on US interceptors like the F4/8/101/102/104/106 (which is very likely), the Mig's IRST is there mostly as a backup for when the radar can't burn through jamming, and likely has a fairly limited range.

Well the range numbers posted for the mig23 IRST were "impressive" but I'm gonna say they were basically best case. Something like 100km+ for a sr-71 in burner etc. Given that its razbam I expect them to use the existing FC3 IRST code until ED improves IRST.

SR71 in burner is not exactly your average case though. IDK if they can recycle FC3 code either, since those systems by definition are waaaay simplified. I guess we will see.

Considering how limited the MiG-29 and Su-27's IRSTs are, I doubt the MiG-23's could see anything useful at that range. Gordon and Komissarov's books on the two newer fighters list the following performance:

For the MiG-29's KOLS-29:

"Detection Range (fighter-type target), 15km (9.3 miles)

Steady tracking range, 12 km (7 miles)

Laser ranger operating range, 200-6500m (660-21,325 ft)

Scan time: large field of view, 3.5 seconds, small field of view, 2.0 seconds"[1]

For the Su-27's OLS-27:

"Detection Range of 50km (31.25 miles) in pursuit mode and 15km (9.3 miles) in head-on mode. (Some press reports state that the OPES-27 can detect a small incoming target, such as a fighter, at 40km (24.8 miles) and an outbound target at 90-100km (56-62 miles); this may apply to late models of the system.) Laser rangefinding is possible within 0.3-3 km (0.18-1.8 miles), with a measurement accuracy of 10m (32 ft 10 in) in range and 5 angle seconds in azimuth; target tracking speed is in excess of 25 deg/sec."[2]

Given what was written in the article AeriaGloria posted, I'm guessing the longer range figures are for a later model of the system for the FLANKER family (as Gordon and Komissarov surmise), and/or probably against a very high flying contact in afterburner against a cold space background (like Harlikwin's SR-71 or maybe a MiG-25 or -31). In that case, it would be a white dot against black, running at very high speed, and not really useful for engaging or identifying what it is the IRST is tracking.

PIRATE is significantly newer, and based on published material more capable. That said, I'm not holding my breath for an accurate modeling of it in DCS, being a current, state of the art IRST system.

Source:

Yefim Gordon and Dmitriy Komissarov, Famous Russian Aircraft, Mikoyan MiG-29 & MiG-35 (England: Crecy Publishing, 2019), 161.

Yefim Gordon and Dmitriy Komissarov, Famous Russian Aircraft, Sukhoi Su-27 & 30/33/35/37 (England, Crecy Publishing, 2019), 231.

Considering how limited the MiG-29 and Su-27's IRSTs are, I doubt the MiG-23's could see anything useful at that range. Gordon and Komissarov's books on the two newer fighters list the following performance:

 

For the MiG-29's KOLS-29:

"Detection Range (fighter-type target), 15km (9.3 miles)

Steady tracking range, 12 km (7 miles)

Laser ranger operating range, 200-6500m (660-21,325 ft)

Scan time: large field of view, 3.5 seconds, small field of view, 2.0 seconds"[1]

 

For the Su-27's OLS-27:

 

"Detection Range of 50km (31.25 miles) in pursuit mode and 15km (9.3 miles) in head-on mode. (Some press reports state that the OPES-27 can detect a small incoming target, such as a fighter, at 40km (24.8 miles) and an outbound target at 90-100km (56-62 miles); this may apply to late models of the system.) Laser rangefinding is possible within 0.3-3 km (0.18-1.8 miles), with a measurement accuracy of 10m (32 ft 10 in) in range and 5 angle seconds in azimuth; target tracking speed is in excess of 25 deg/sec."[2]

 

Given what was written in the article AeriaGloria posted, I'm guessing the longer range figures are for a later model of the system for the FLANKER family (as Gordon and Komissarov surmise), and/or probably against a very high flying contact in afterburner against a cold space background (like Harlikwin's SR-71 or maybe a MiG-25 or -31). In that case, it would be a white dot against black, running at very high speed, and not really useful for engaging or identifying what it is the IRST is tracking.

 

PIRATE is significantly newer, and based on published material more capable. That said, I'm not holding my breath for an accurate modeling of it in DCS, being a current, state of the art IRST system.

 

Source:

Yefim Gordon and Dmitriy Komissarov, Famous Russian Aircraft, Mikoyan MiG-29 & MiG-35 (England: Crecy Publishing, 2019), 161.

Yefim Gordon and Dmitriy Komissarov, Famous Russian Aircraft, Sukhoi Su-27 & 30/33/35/37 (England, Crecy Publishing, 2019), 231.

Its a bit of a apples to oranges comparison really.

I mean pirate is a modern dual band MWIR/LWIR staring array using tech thats 20-30 years newer than what the russians were using in the older migs.

The KOLS-29 is 1st generation stripe detector with lead selenide as the detector element. I have a fair bit of engineering info on the KOLS-29 and those figures you post are about right, if on the bit optimistic side. It was basically designed to work in WVR with the HMS system and provide passive targeting information for the archer/AA guns/ and A/G gun/rocket attacks.

I have less info on the OLS-27 but its a larger sensor and designed for longer range detection, though I don't think it can provide a firing solution at long range. Again, most likely using a stripe led selenide detector. The range improvement vs the KOLS is likely a function of aperture size/optics.

For the mig23 the whole system seems really weird to me. Reportedly its got a longer range than the mig29 KOLS system (fine I can buy that for a dollar). But its placement on the underside of the plane means its got minimal/no look up capability unless the nose is pointing up, and those early detector systems mostly sucked looking down since they didn't really have the signal processing to do clutter processing so thats going to limit the range on that somewhat. The numbers I recall posted by a somewhat reputable source put it near the SU-27 IRST for detection ranges, which I find a bit dubious for look down.

SR71 in burner is not exactly your average case though. IDK if they can recycle FC3 code either, since those systems by definition are waaaay simplified. I guess we will see.

Yeah, I mean I'd expect the mig23 IRST to mostly work at a few tens of km with a rear aspect target.

As for Raz, I mean they aren't exactly known to write their own systems code when they can avoid it and use ED's API's (not judging, but they've flat out said that).