EOS ranging

[Frostie]

With EOS in lockon your able to lock targets in afterburner over 20km headon and over 60km in a chase but how realistic is this measurement of range?

 

How, in RL would or does the system differentiate between a head on contacts heat source and a chased one, and can these systems really give accurate ranges?

[DarkWanderer]

EOS is a thermal seeker paired with a laser rangefinder. The range is provided by the latter at 0-~25km distances. Also, RLPK can obtain range data from radar "slaved" to EOS (IIRC, "STT without lock" mode).

[Majesco]

IMO, EOS in FC doesn't have much effect and difficult to measure

EOS ranging for fighters detection is around 5km or closer,in many cases EOS is unable to detect heat signal from air targets at 12 o'clock, very close range 1-2km

But big cargo planes can be detected by IRST at distance of over 10km

Edited May 12, 2009 by Majesco

[RvETito]

With EOS in lockon your able to lock targets in afterburner over 20km headon and over 60km in a chase but how realistic is this measurement of range?

 

How, in RL would or does the system differentiate between a head on contacts heat source and a chased one, and can these systems really give accurate ranges?

 

I'd say those numbers are pretty realistic. Since the ЕOS picks up IR emmisions (opticaly invisible) it's detection range depends only on that, and external conditions of course. An aircraft is mostly IR emmiting in the rear hemisphere, that's why the EOS will "see" much more heat from behind. Especialy if the target is using afterburner- it can easily pick it up at 50+ km in chase. This range highly depends on the power settings of the engines of the target. In one word, the EOS doesn't care about the aspect like the doppler radar, it only picks up IR emmisions. Therefore it's operation depends so much on the external conditions- day, night, clouds, moisiture. In clean night at high altitude it should be able to pick up an afterburning target in chase at maximum range.

 

In order to track the target the EOS needs range, it takes the azimuth and the elevation by itself. Like Darkwanderer wrote, the radar can be slaved to it and it is the source providing the range. The radar sends very short, low power output discrete pulses that are so weak that I suppose can be picked up only by the most modern RWR, if possible at all. What is more important in this mode (partialy modeled in LO) is that in case the EOS loses track of the target (for example it goes into a cloud) the radar will automaticaly turn on in full emiting mode and will look at the last known position of the bandit (datalink EOS-radar). Once the EOS picks up the target again the radar goes off again, automaticaly. This how a maximum "stealth" attack is made, I mean with minimum use of the radar.

 

The EOS indeed has a built-in laser rangefinder which AFAIK works within 10km range (as per MiG-29 combat manual) and in that case the radar goes fully passive. That's the most hidden attack.

Edited May 12, 2009 by =RvE=Tito

[Alfa]

With EOS in lockon your able to lock targets in afterburner over 20km headon and over 60km in a chase but how realistic is this measurement of range?

 

How, in RL would or does the system differentiate between a head on contacts heat source and a chased one, and can these systems really give accurate ranges?

 

The ranges you mention sound quite plausible. Like Tito wrote, the range at which the EOS can pick up a target depends on the strength of the target's heat signature in relation to its surroundings - i.e. factors like:

 

- engine power of target aircraft - optimal condition would be something like a twin engined fighter in afterburner.

 

- whether the EOS has unobstructed line of sight to the target's heat source(engines) - optimal condition would be rear aspect.

 

- the background at which the EOS is looking at it - optimal condition would be from below with the background of a clear cold sky at night. Things like sunlight or radiated heat from the ground(i.e. when looking at the target from above) decrease the effectiveness of IR tracking.

 

- atmospheric conditions - moisture due to things like clouds, fog, rain etc can "mask" the heat source and decrease range.

 

However, to address the title of the thread, the EOS cannot measure this range and doesn't need it to track a target - an EOS "lock" only provides the angular position of the target. Range measurement is only needed for "LA" - i.e. to determine whether target is within launch parameters of selected missile or for aiming the cannon. For this the WCS uses either the radar as Tito described or(at shorter range) the associated laser range finder, which IIRC has a max effective range of some 8 km - but being an optical device itself, the laser is also affected by atmospheric conditions.

[sniffer]

The EOS indeed has a built-in laser rangefinder which AFAIK works within 10km range (as per MiG-29 combat manual) and in that case the radar goes fully passive. That's the most hidden attack.

 

Everything is correct but there is one important difference between Sukhoi EOS and MiG EOS...

Suhkoi system OEPS-27 (EOS) had Geofizyka OŁS-27 optical locator which can detect targets from head-on and from behind as all of You mentioned. This optical system is much more effective then MiG EOS. In MiG's optical locator is Geofizyka KOŁS-29 which can only detect from rear hemisphere.

 

Some KOŁS-29 detection ranges:

- normal condictions (e.g. clear skies): 12-18 km

- ground in background: 6-10 km

- clouds in background: 4-8 km

 

Laser rangefinder is working from 200 m to 3-6,5 km

 

Everything what I wrote is about early MiG-29A so just don't scream that S or SMT or whatever had newer, better version etc. ;-)

[RvEYoda]

Good thread, keep the information coming :)

[topol-m]

Everything is correct but there is one important difference between Sukhoi EOS and MiG EOS...

Suhkoi system OEPS-27 (EOS) had Geofizyka OŁS-27 optical locator which can detect targets from head-on and from behind as all of You mentioned. This optical system is much more effective then MiG EOS. In MiG's optical locator is Geofizyka KOŁS-29 which can only detect from rear hemisphere.

 

Some KOŁS-29 detection ranges:

- normal condictions (e.g. clear skies): 12-18 km

- ground in background: 6-10 km

- clouds in background: 4-8 km

 

Laser rangefinder is working from 200 m to 3-6,5 km

 

Everything what I wrote is about early MiG-29A so just don't scream that S or SMT or whatever had newer, better version etc. ;-)

 

Aren`t these ranges too short for EOS. I thought it is more powerfull than a missile seeker (like R-73`s for exemple)? And as Yoda gave an example of R-73 able to track a drone for up to 30 km shouldn`t the EOS be even more capable? In the game you first track a target with EOS then when it comes close enough the missile begins tracking it too.

[Boberro]

I am suprised a bit... Are these really true values?

 

I don't expect LO's values but shouldn't they be a bit higher?

[RvEYoda]

Aren`t these ranges too short for EOS. I thought it is more powerfull than a missile seeker (like R-73`s for exemple)? And as Yoda gave an example of R-73 able to track a drone for up to 30 km shouldn`t the EOS be even more capable? In the game you first track a target with EOS then when it comes close enough the missile begins tracking it too.

 

It is probably more powerful, but bear in mind this was something the pilot called

*it was like a flare" (so very very VERY much hotter than aircraft), and of

size of a drone, what kind of drone i dont know. But it should have been very bright.

 

And i think sniffer said his numbers are for some early mig29A used some downgraded system, the modern

sukhois are likely much better.

Edited May 13, 2009 by =RvE=Yoda

[topol-m]

The Su-35`s EOS:

 

The OLS-35 offers sigficant improvements over the OLS-27 of previous Su-27 versions, owing to the use of more advanced electronics, algorithms and software. Information regarding detection ranges and detection/tracking zones vary across sources. The estimated range for detection from a tail-on aspect has been reported to be 70-90 km and up to 40-50 km for head-on engagement for non-afterburning targets. The detection and tracking zone is 55-60 ° upwards, 15 ° downwards, and between 60° and 90° in azimuth. The laser is capable to range aerial target up to 20 km and ground targets at 30 km with a precision of five meters. Alternatively, the Su-35 may be fitted with one of the new electro-optical systems developed by NIIPP (Scientific Research Institute of Precision Instruments Engineering) for the MiG-35.

[Moa]

The Su-35`s EOS:

 

The OLS-35 offers sigficant improvements over the OLS-27 of previous Su-27 versions, owing to the use of more advanced electronics, algorithms and software. Information regarding detection ranges and detection/tracking zones vary across sources. The estimated range for detection from a tail-on aspect has been reported to be 70-90 km and up to 40-50 km for head-on engagement for non-afterburning targets. The detection and tracking zone is 55-60 ° upwards, 15 ° downwards, and between 60° and 90° in azimuth. The laser is capable to range aerial target up to 20 km and ground targets at 30 km with a precision of five meters. Alternatively, the Su-35 may be fitted with one of the new electro-optical systems developed by NIIPP (Scientific Research Institute of Precision Instruments Engineering) for the MiG-35.

 

Thanks for the info. I'm sure those EOS ranges are the maximums found under good conditions. It is good to question all manufacturer's numbers and ask what the range is under a variety of conditions. It would be a stretch to say manufacturers release deceptive numbers, but you have to remember they are trying to sell systems so always 'put their best foot forward'. In practice the EOS probably works reliably (and without too much effort for average pilots) at shorter ranges than published.

 

Here's an analogy, the maximum speed of most modern fighter aircraft is quoted as ranging between Mach 1.5 to 2.5, so it is easy to wonder why you're not getting that speed when in game. Then you find out that while the quoted speed is true is also was the maximum clean (true) airspeed over a 2 minute non-maneuvering sprint when level at 60 k feet, and the actual airspeed at sea level you should expect is Mach 1.1 after diving and armed, and in a short-range flight where fuel is a limitation. Guess which top airspeed (1.1 or 2.5 Mach) is going to be more typical of an aircraft in normal use?

[GGTharos]

There's a difference between a head-on search (search function, important!) and point the IRST right where it's supposed to be looking at ...

Also there's a difference between a head-on target and a drone that glows super-hot. Keep this in mind.

 

Aren`t these ranges too short for EOS. I thought it is more powerfull than a missile seeker (like R-73`s for exemple)? And as Yoda gave an example of R-73 able to track a drone for up to 30 km shouldn`t the EOS be even more capable? In the game you first track a target with EOS then when it comes close enough the missile begins tracking it too.

[sniffer]

And i think sniffer said his numbers are for some early mig29A used some downgraded system, the modern

sukhois are likely much better.

 

Exactly! A version... And that's what I wanted to point - some difference in MiG & Sukhoi optical systems... Second thing is I'm sure that later versions is much more upgraded but don't know their data. Data provided by me was from 9.12 manual and such data are always different (more accurate) from any 'press publications' (which I call always as 'rounded data'). Eg. Y.Gordon in his publication about Su-27 wrote that OŁS-27 laser rangefinder can calculate range in 300 m - 3 km (hard to believe that KOŁS-29 can calculate to maximum 6,5 km). One thing is sure: always will be some differences in such data... but better this that 'no data' :smilewink:

 

As curiosity - direct from Wiki about Su-30MKK (Chineese version):

OEPS-30 optronic (electro-optical) detection system: Chinese call this system optronic radar system, and it is consisted of two major components:

- OLS-30 (52Sh) optronic system weighing 200 kg includes laser and IR sensors. In comparison to its predecessor OLS-27 (Izdeliye 36Sh) on Su-27, the IR detection range nearly doubled to > 90 km from the original 50 km. The range of laser range finder is increased to > 10 km from the original 6 km.

- Sura-K helmet mounted system (HMS): The field of view (FoV) is greatly increased to +/- 60 degrees in comparison to the +/- 8 degrees of the ASP-PVD-21 HMS originally used on Su-27.

 

As You can see, progress is very impressive...

Edited May 14, 2009 by sniffer

[topol-m]

That might be of interest: http://www.aviapedia.com/video/new-mig-35-ols-video

[GGTharos]

Forget the MiG-35 OLS. It's old technology adapted to do sensor fusion etc, but the technology itself is as bad if not worse than an IR camera I was testing for the military fifteen years ago.

 

What they have done is very good for situational awareness around the aircraft, but they haven't really made the underlying technology more efficient. As they start using better CCDs that will happen, but not yet.

 

If you want to see something scary in terms of an OLS-like setup, check out the F-35's DASS.

[Wilde]

With EOS in lockon your able to lock targets in afterburner over 20km headon and over 60km in a chase but how realistic is this measurement of range?

 

As I recently linked somewhere else there's someone in this forum referring to this question. He quoted the Su-27's flight book saying this.

 

The EOS can indeed acquire those targets if the conditions allow it. But as someone else correctly stated the MiG-29 has a "weaker" EOS. That is because the MiG's EOS is simply smaller.

 

As for your second question, that's difficult. There are a number of factors. For example if the acquired signature is known it's probably easier to get a range figure. Also the system isn't plain IR, but also optical. If visibility is good it can simply "see" the target. But whatever, I'd assume at large distances the scanned range would be a gross estimation. And that's good enough. Attacking someone with a heater from an odd 90km would be just impossible in real life.

[Frostie]

Forget the MiG-35 OLS. It's old technology adapted to do sensor fusion etc, but the technology itself is as bad if not worse than an IR camera I was testing for the military fifteen years ago.

Im sure you imagine this to be so, but im quite sure the reality is a lot more than something you've worked on in your garage.:lol:

 

-detect not-afterburning target on the 45km range and more

 

'OLS created in NII PP is not just another modern instrument. This is the totally new device which completely fits the idea of 5th generation combat plane. Already today parameters of the OLS are about ten times better then the ones of old systems. But NII PP is not going to stop. The next stage of the development will be to upgrading the optical complex intelligence level and to combine it with onboard radar.'

[Vekkinho]

I believe I already mentioned it EOS could be used along the N019 even 25 years ago!