Capabilities of modern Infra-red search and track systems (OLS, PIRATE, EOTS)

[Firn]

IRST seems to become more and more common for modern mulitrole fighters. Various Russian, European and US systemes are deployed or in development and I wonder just how important a role IRST will play in general in aerial warfare.

OLS

PIRATE (german, detailed info)

PIRATE basic information

EOTS and DAS

 

[gf0012-aust]

No single system is sufficient as in "all singing, all dancing".

IRST is but one seeker type.

The USAF for example shifted development to multi-seeker systems a few years back, in fact the last tests I recall used GTMI to find and lock and a multi seeker headed missile to (successfully) engage a mobile evading target.

Similarly, tracking is also not just a shot show, (and you can extrapolate this to the well worn sensor fusion/networking buzzwords) where disparate sensor systems via separate platforms can co-operate if not hand off processing and control prior to release, and during weapons release and weapons flight.

so, yes its important - but as a complimentary solution to other capabilities. its importance and relevance is always going to be mission specific

 

[Firn]

No single system is sufficient as in "all singing, all dancing".

IRST is but one seeker type.

The USAF for example shifted development to multi-seeker systems a few years back, in fact the last tests I recall used GTMI to find and lock and a multi seeker headed missile to (successfully) engage a mobile evading target.

Similarly, tracking is also not just a shot show, (and you can extrapolate this to the well worn sensor fusion/networking buzzwords) where disparate sensor systems via separate platforms can co-operate if not hand off processing and control prior to release, and during weapons release and weapons flight.

so, yes its important - but as a complimentary solution to other capabilities. its importance and relevance is always going to be mission specific

A common-sense post. I think nobody with a decent understanding thinks suddendly IRST will replace the great variety of sensors already in place and in development. There is a finite array of signals in waveform which lend themselves to detection and communication. The greater the spectrums you can skillfully manipulate, interpretate, share and combine the more difficult is it to evade detection. There is no doubt that "sensor fusion" and networking are the future and already part of the present.

Personally I think that the recent advances in technology and the intrinsic advantages the specifc spectrum(s) Infrared offers will make it increasingly important relative to other sensors.Albeight there are some distinct disadvantages the plusses are great. Easy to compute, easy to interpret for humans, a very high resolution of the emitting environment, the passive nature...

 

[SpudmanWP]

I read the OLS info on:

http://www.aviapedia.com/video/new-mig-35-ols-video

New OLS is intelligence system of technical vision to work in realtime of fast combat environment. In air combat complex allows:
- detect not-afterburning target on the 45km range and more;
- identify this target on 8-10km range;
- estimate aerial target range up to 15 km.

For the ground targets complex allows:
- tank effective detection range up to 15 km, aircraft carrier - 60-80 km;
- identify the tank type on the 8-10 km, aircraft carrier type - 40-60 km;
- estimate ground target range up to 20 km.

Is it me, or does the A2A modes seem real short? I don't think the F-35 has anything to fear about being detected before it finds the Mig.

 

[Firn]

Is it me, or does the A2A modes seem real short? I don't think the F-35 has anything to fear about being detected before it finds the Mig.

Seems that a lot here is about the F-35 vs Russian aircraft.

Even more than with the RCS the ICS (Infrared Cross section, made up myself) is varies greatly with the relative angle/position of the emitting source(s) to the sensor. Rockets for example have a very high rear and lateral ICS aspect, especially when launched by a GBAD (abrupt change from a "cold" to a very hot emission). Their high speed (Mach 3+) greatly heats up also the tip and wing area and surrounding air, giving them also a high frontal ICS. This is also part of the reason why the F-35 has infrared sensors in a couple of locations to provide a full 360° IRST coverage. It is an excellent way to detect approaching passive missiles (infrared seeker or not-yet active radar seeker). The OLS too has the same coverage, the PIRATE has a wide angle in the frontal arc, EOTS alone no rear coverage.

But with all the different ICS of the various targets (airplanes, tanks, ships), the different sensitivity of the IRST sensors, the uneven background noise and the changing weather conditions it is impossible to come up with a precise number for detection. Passive ranging is also not as straightforward as "lazing" it with a laser, which might warn the target. Still it is a field which has made and is making huge leaps forward.

 

[gf0012-aust]

But with all the different ICS of the various targets (airplanes, tanks, ships), the different sensitivity of the IRST sensors, the uneven background noise and the changing weather conditions it is impossible to come up with a precise number for detection. Passive ranging is also not as straightforward as "lazing" it with a laser, which might warn the target. Still it is a field which has made and is making huge leaps forward.

When I was Consulting I was invited to view/review a long range demo of a IR targetting system which was also cued using a laser for alternating targetting.

The manufacturers claim was "nn" km - the useful range, that is where a target could be confidently identified before weapons release was actionable - was about 65% of their declared range.

INOW - statistics mean bugger all and only begin to have relevance when exposed to real life tests.

I learnt long ago to ignore manufacturers claims - esp IRST.

 

[SpudmanWP]

OLS ns nowhere near the capability of the F-35s EOTS/DAS combo.

OTS only has two sensors, both of which are gimbled. It can only see to the front and bottom of the fighter.

 

[Feanor]

OLS ns nowhere near the capability of the F-35s EOTS/DAS combo.

OTS only has two sensors, both of which are gimbled. It can only see to the front and bottom of the fighter.

Iirc the OLS on the proposed MiG-35 was claimed to provide 70% spherical coverage. I'll see if I can find that article again.

 

[Scorpion82]

Iirc the OLS on the proposed MiG-35 was claimed to provide 70% spherical coverage. I'll see if I can find that article again.

Simply stick to the data.
OLS-UEM +/-90° azimuth coverage and +60°/-15° elevation coverage. OLS-K 360° azimuth coverage and the lower hemisphere. Means OLS-K provides no coverage above the aircraft, but below and at same alt.

 

[SpudmanWP]

OLS is still not comparable because both sensors are gimbled and cannot cover their entire coverage at the same time. It must rotate to cover it's whole area.

Also, where does it say that the lower sensor does anything besides standard FLIR, Laser Designator, or TV functions?

 

[Firn]

OLS is still not comparable because both sensors are gimbled and cannot cover their entire coverage at the same time. It must rotate to cover it's whole area.

Also, where does it say that the lower sensor does anything besides standard FLIR, Laser Designator, or TV functions?

While the sensors of the OLS must ideed rotate I wonder if they are not more capable than the spread out sensors of the F-35's DAS. The DAS seems to built to warn of threats from a shorter range...

 

[SpudmanWP]

The F-35's EOTS can view to the front , bottom, and rear much like the OLS. The DAS adds to this, a full 360 coverage envelope.

Gains much, gives up nothing.

 

[Firn]

The F-35's EOTS can view to the front , bottom, and rear much like the OLS. The DAS adds to this, a full 360 coverage envelope.

Gains much, gives up nothing.

I was wondering just how capable the sensors of the DAS are. A large rotating IR sensors should have better resolutions and thus longer IRST detection and indentification ranges. EOTS should cover a very large area however as with other IRST systems we don't know exactly how large it is.

 

[Firn]

Seems like IRST seems to getting more and more popular. The F-15 variant of Singapore and the Boeing F/A-18E/F Super Hornet both will use IRST. It seems to get an ever more important part of the sensor and defensive suite of a modern fighter, used to search for, detect and track targets and threats and to fly more safely in the dark.

 

[SpudmanWP]

The EOTS (gimbaled IRST) in the F-35 covers the front, sides, and bottom of the F-35. It has full optical zoom capability. It's area of coverage is better than any other operational aircraft today.

The DAS system is a series of 6 IIR cameras that cover the FULL 360 degree envelope around the airframe. NO OTHER aircraft has anything like it. The DAS is way more than a simple MLD.

 

[gardnerdesign]

The development of IRST is essential for future aircraft and space craft; therefore it is important to begin utilizing this system now as it will evolve into a multifunctional and powerful system that will give its users unmatchable advantages.

We are developing several sub-orbital and orbital military craft that will serve in both offensive and defensive roles. IRST lends itself to such craft as the higher the altitude the greater the range of an IRST system. When paired with an ECM it is very useful because these fast moving high altitude craft can only be intercepted by even faster moving weapons, which cannot possibly hide their very large infrared signatures.

Ballistic Missile Defense is more a priority now than ever and aircraft as well as spacecraft performing this role will gain huge offensive and defensive advantages from the integration of robust IRST systems. Especially in the boost and midcourse phases of a ballistic trajectory( think forward deployed aircraft equipped with an IRST system and armed with PAC 3 or THAAD interceptors or for a space based missile defense)

IRST could be pared with the Multiple Kinetic Kill Vehicle and the ECM system of an aircraft to allow for active defenses against incoming missiles. A robust IRST system with a powerful laser could use the laser with a variable refractive lens to illuminate large areas; giving it an active search capability to supplement its passive ability. As well as allowing for targeting information to be relayed to weapon systems.

The system could potential be used for jam proof communications with space craft, aircraft and ground positions as well as more complex data transfers. Also with a powerful enough laser system integrated with the IRST a craft could use the system to blind infrared seekers on missiles other IRST’s or even as a dazzler system to be aimed against enemy pilots.

Finally all these capabilities can be accomplished with about 4 multispectral infrared sensors that were actively cooled (to increase passive resolution) and one high powered laser. Two of the infrared cameras would use 360 degree lenses, (which is currently possible, and could be made more capable with further investment into this technology) two would use traditional 360 degree turrets and would contain a high zoom capability and the laser illuminator(s). The laser would be split into 2+ beams or focused as one, and would utilize lenses to vary the refraction of the laser.

 

[Firn]

The EOTS (gimbaled IRST) in the F-35 covers the front, sides, and bottom of the F-35. It has full optical zoom capability. It's area of coverage is better than any other operational aircraft today.

You seem to quite sure of that. Do you also have enough information of the various systems to back it up?

The DAS system is a series of 6 IIR cameras that cover the FULL 360 degree envelope around the airframe. NO OTHER aircraft has anything like it. The DAS is way more than a simple MLD.

I agree with that. In a fight within visual range it should be a great advantage as the pilot should be able to "see through" with his Helmet-Mounted Sighting System and might with the modern ASRAAMs even engage targets who sit in the rear.

 

[SpudmanWP]

Here is a good writeup on the JSF's Avionics. It explicitly states "zoom" in it's capabilities.

If you look at any of the JSF Briefings that show the EOTS, it shows the FOV of the EOTS to cover the front, bottom, and partial rear of the AC.

I have gathered all the JSF Program Docs here

 

[Firn]

Thanks for the links, I always appreciate it when somebody can point to a source.

P.S: I'm really like the way the F-35 integrates EOTS into the overall sensor suite and the bigger network.

P.P.S: Gardnerdesign, I will come back to your post.

 

[Firn]

Here we have a very nice video of the F35's EO-DAS.

A lot of interesting modes weaved into a seemingly very capable system. The launch components of GBADs will face a far greater dangers than before. The IRST mode coupled with the TA and indentification should give the F-35 the capability to spot any launch quickly and precisely. Lazing it or a quick radar beam or a combination of both according to the situation will geolocate that launcher in a hurry and provide a clear targeting solution. Some thoughts about the "ICS" of rockets and aircrafts...

Even more than with the RCS the ICS (Infrared Cross section, made up myself) is varies greatly with the relative angle/position of the emitting source(s) to the sensor. Rockets for example have a very high rear and lateral ICS aspect, especially when launched by a GBAD (abrupt change from a "cold" to a very hot emission). Their high speed (Mach 3+) greatly heats up also the tip and wing area and surrounding air, giving them also a high frontal ICS. This is also part of the reason why the F-35 has infrared sensors in a couple of locations to provide a full 360° IRST coverage. It is an excellent way to detect approaching passive missiles (infrared seeker or not-yet active radar seeker). The OLS too has the same coverage, the PIRATE has a wide angle in the frontal arc, EOTS alone no rear coverage.