Qioptiq logo DSEi Top Engineer Harris

THERMAL WEAPON SIGHTS GET SMARTER By Michael J. Gething

While the numbers of combat troops operating in Iraq and Afghanistan have been vastly reduced since the start of this decade, significant numbers of ground forces are still in action, assisting the national troops of these countries in the fight against the so-called ISIS (or Daesh) forces.

As has been noted in these pages before, many engagements continue to take place in areas of minimal ambient light, where the thermal weapon sight is often preferred over the image-intensified sight, or at night. This feature offers a reprise and update on the TWS scene, highlighting several new products and indicating the way forward with more and more products using uncooled microbolometer technology to reduce the size, weight and power (SWaP) of the genre.

While the most numerous thermal sight in service today is, perhaps, the US Army’s AN/PAS-13 Thermal Weapon Sight (TWS) family (covered in its various forms and applications in previous issues of Battlespace) produced by three major manufacturers (BAE Systems, Leonardo DRS and Raytheon), the US Army is now working up a new generation of TWS, known as the Family of Weapon Systems (FWS).

The FWS project is managed by the Product Manager Soldier Manoeuvre Sensors (SMS) within the US Army’s Program Executive Office (PEO) Soldier. It is described as “a family of weapon sights that enable combat forces to acquire and engage targets with small arms and to conduct surveillance and Enhanced Target Engagement under day/night obscurants, no-light, and adverse weather conditions.” It leverages advances in thermal and low-light level sensors to produce three variants: Individual (FWS-I), Crew-Served (FWS-CS), and Sniper (FWS-S) weapon sights which can be mounted in-line with a day optic or used in stand-alone mode.

According to PEO Soldier documentation, FWS “integrates a smaller pixel focal plane array [FPA] in multiple large format sizes to improve sensitivity, clarity, and range, while simultaneously reducing the size, weight and power consumption of both the Crew-Served and Sniper variants.”

The “smaller pixel FPA” actually refers to the space between pixels on the FPA (known as the pixel-pitch) which means that for a given FPA array format (e.g. 320×240) the resultant detector becomes smaller and lighter, while reducing power consumption. It also means that a greater array format (e.g. 640×480) can be accommodated in a similar sized unit to the earlier generation, allowing improved resolution for the user. Thus, while the original iterations of AN/PAS-13 TWS, which featured a pixel pitch of 25-microns, reducing to 17-microns by the final production of the TWS II tranche, the FWS uses a 12-micron pixel-pitch uncooled microbolometer, fast becoming the detector of choice, as the materials technology has improved the ease of manufacture. No cooling engine reduces both weight and power consumption. All the FWS variants operate in the long-wave infrared (LWIR) spectral range.

Another important element of FWS-I is the incorporation of a rapid target acquisition (RTA) facility. This uses WiFi comms to transmit the image from the weapon sight itself to the battery pack of the soldier’s AN/PSQ-20 Enhanced Night-Vision Goggle III (ENVG III), attached to the back of the soldier’s helmet. The FWS-I image is then transmitted to the ENVG III eyepiece through fiber optic cables, appearing as a window in the eyepiece field-of-view (FoV). Thus, it is possible for the soldier to remain in cover and just point the weapon and sight to the target – the ‘shoot around corners’ scenario.

According to PEO Soldier, the FWS-I can be used on M4 and M16 series carbines/rifles, the M249 Squad Automatic Weapon (SAW), M136 Light Anti-Armour Weapon (LAW), and the M141 Bunker Defeat Munition. Both BAE Systems and DRS Technologies (now Leonardo DRS) bid into the FWS programme and, in October 2016, BAE Systems was awarded a USD13.5 million low rate initial production (LRIP) contract to deliver more than 100 FWS-I sights to the US Army.

Following further technical development of the FWS-CS (for use on for the M240B series of medium machine guns, the M2 HB 50-calibre heavy machine gun, and the Mk 19 Automatic Grenade Launcher) and FWS-S (for the M24, M110 and M107 sniper rifles) variants, on 26 September 2016, the US Army awarded both companies contracts to develop and provide FWS-CS weapon sights. Over the life of the contracts (with an expected completion date of September 2023), the BAE Systems contract is worth USD383.9 million and the DRS Technologies contract, USD337.7 million. BAE Systems announced that it had received a USD10.5 million initial development order for FWS-CS in November 2016.

Speaking with both BAE Systems and Leonardo DRS at the recent DSEI show in London, neither company were promoting FWS or were inclined to add further details on the programme, no doubt saving what new revelations are permitted for the AUSA show in Washington DC in October.

Leonardo DRS was, however, promoting its Sniper Precision Acquisition Rifle Thermal Night (SPARTN) sight – a clip-on sight to be mounted forward of the day optic telescope on the sniper’s weapon of choice. According to company literature, SPARTN uses a cooled 640×480 FPA Mercury, Cadmium Telluride (MCT) detector with a 12-micron pixel pitch, operating in the 3.4- to 4.8-micron mid-wave infrared (MWIR) band. Although not specific on range, the company claims that SPARTN has a “proven range detect performance [that] will match or exceed current sniper weapons systems capabilities”.

Of the other US companies involved in thermal weapon sights exhibiting at DSEI, L-3 Warrior Systems was promoting the AN/PAS-13G(V)1 Light Weapon Thermal Sight (LWTS), using a 640×480 uncooled microbolometer with a 17-micron pixel pitch; while Raytheon (heavily involved in the production of the AN/PAS-13 family over the years) was not promoting any thermal sights at the show. What did emerge during the show, however, was that UTC Aerospace Systems had acquired N2 Imaging Systems of Irvine, Ca., the company was unable to discuss any thermal sights at this time.

FLIR Systems, however, was showing some thermal sights at DSEI – the latest iteration of its High-performance In-line Sniper Sight (HISS), the MIlsight HISS-XLR with a cooled 640×480 detector operating in the MWIR band; and the Thermosight T75 long range thermal weapons sight, using an LWIR 640×480 uncooled microbolometer with a 17-micron pixel-pitch. When asked of his opinion on the introduction of lower pixel pitches, Adam deAngelis, FLIR’s director of marketing for surveillance, told Battlespace that “High Definition resolution will be making its way into our sights” although he was unable to be specific on FPA and pixel-pitch values.

Crossing the Atlantic to the UK, Excelitas Qioptiq used DSEI to promote its Dragon-C640 (Compact) model using an uncooled LWIR 640×512 FPA on a 25-micron pixel pitch, as well as the other four models in the family: Dragon-S (Sniper), Dragon-SR (Short Range) and Dragon-MR (Medium Range) – all using an uncooled LWIR 320×240 FPA on a 25-micron pixel pitch; plus the Dragon-LR (Long Range) using an uncooled LWIR 640×512 FPA, again on a 25-micron pixel pitch, allowing a longer detection range. To date, sales of the Dragon thermal sight (of all models) come to 2,500, spread across customers in Europe, the Middle East and Asia.

The Dragon has now replaced the earlier VIPIR2 product as the baseline for the British Army’s FIST (Future Integrated Soldier Technology) thermal sight. Although no longer actively promoting VIPIR2, Excelitas Qioptiq continues to support systems in service.

Company sources indicated to Battlespace at DSEI that a development programme for an uncooled 12-micron thermal sight to replace the current Dragon-S model would begin in Q1 of 2018. They also indicated that the Saker fused weapon sight, launched in 2012, has now matured and initial production models have been acquired by specialist user groups in the UK.

Another UK supplier of thermal sights, Thermoteknix, used DSEI to show its TiSight, available in two versions: the TiSight-CO50 clip-on unit, used in conjunction with a day sight; and the TiSight-DV50 direct view thermal sight. Both versions used uncooled Amorphous Silicon thermal detectors and users are offered a choice of a 384×288 FPA on a 25-micron pixel-pitch, 384×288 FPA on a 17-micron pixel-pitch, or a 640×480 FPA on a 17-micron pixel-pitch. According to company literature, a man detection range of 1,300m is claimed for the 25-micron detector and 1,900m for the two 17-micron detectors.

Across the English Channel, Sagem (part of the Safran grouping) continues to market its range of Sword thermal sights, based on those supplied to the French Army under the FELIN programme. Three main versions are available: Sword Light, Sword T&D, and Sword Sniper. All use uncooled, LWIR detectors. Sword Light is understood to use a 384×288 FPA but the pixel-pitch has not been revealed. The FPA configuration and pixel-pitch of the other two models have not been revealed, although as Sagem is a French company, it is probable that the detectors have been sourced from ULIS, a subsidiary of France’s Sofradir specialising in uncooled detectors, known to be working on 12-micron pixel-pitch detectors.

Looking to Eastern Europe, Optix of Bulgaria has evolved its OTS-100M sniper sight into the IdentifieR-100, which uses an uncooled LWIR microbolometer with a 640×480 FPA and 17-micron pixel pitch. Poland’s Bumar PCO produces the SCT Rubin thermal sight (in service with the Polish Army) with an uncooled LWIR microbolometer with a 384×288 FPA although the pixel-pitch is unspecified. Also from Poland comes the UCT-1 series of thermal sights, based on an uncooled LWIR microbolometer with a 640×480 FPA and 17-micron pixel pitch, available as either direct view sights of clip-on, ahead of an existing day optic.

The latest iteration of the PT3 thermal sight from Russia’s Shvabe Defence and Protection (formerly the Novosibirsk Instrument Making Plant, NIMP) is offered with an uncooled LWIR microbolometer with a 640×480 FPA and 17-micron pixel pitch.

Heading south, Turkey’s Aselsan continues to promote its Python and Boa thermal sights, using the same uncooled LWIR VOx microbolometer with a 384×288 pixel FPA but unspecified pixel-pitch. The Python is a general purpose sight with a ×3 magnification and, with a ×6 telescope, it becomes the Boa for use by snipers.

From Elbit Systems of Israel comes the Lily family of thermal sights – Lily-S (short-range), Lily-M (medium range) and Lily-L (long-range for snipers) – all of which use uncooled LWIR VOx microbolometers (indigenously produced by SCD of Israel), with Lily-S/-M using 384×228 FPA configurations and Lily-L having a 480×384 FPA. No details of the pixel-pitch are available.

 

While the Lily family comes from the Electro-Optics (ElOp) side of Elbit, the XACT th thermal weapon sight comes from the company’s  ITL Optronics subsidiary. It is offered in three variants –  XACT th64 for special forces (with a laser pointer and video feed), XACT th65 for rifles/carbines and XACT th100 for heavy weapons. All three models use a shutterless, LWIR, uncooled thermal engine, with a 640×480 FPA and 17-micron pixel pitch.

Meprolight, also from Israel, continues to offer its NOA range using an uncooled microbolometer with a 384×288 FPA, on a 25-micron pixel pitch as its baseline detector. Variants include the lightweight NOA NYX with a ×1.6 optical magnification and ×2 or ×3 digital zoom capability which is claimed to detect human activity out to 900 m. Other models include a NOA  M (with ×4 magnification), NOA L (with ×7 magnification), NOA Dual Field (with ×3 and ×7 magnification) and the NOA XT4 clip-on sight.

TISA-3 is the latest iteration of TWS from Pakistan’s Al Technique Corporation of Pakistan (ATCOP), which uses an uncooled LWIR microbolometer with a 640×480 FPA and 17-micron pixel pitch. Company literature claims TISA-3 has a detection range of 1,600m for a man-sized target

Meanwhile, in the Far East, the EO Systems Company of South Korea is offering the TWS-VM themal sight, using an uncooled VOx microbolometer with a 320×240 FPA with ×3 and ×6 magnification  and the MTWS, in versions for assault rifles and crew-served weapons using an uncooled VOx microbolometer with a 320×240 array; and the MTWS-LR sniper variant with a 640×480 FPA. No pixel-pitches are specified in company literature.

The Uralis thermal sight from Singapore Technologies Electro-Optics (STELOP) is available as a sight for assault weapons, using an uncooled LWIR microbolometer with a 320×240 FPA on a 25-mircon pixel-pitch. The Uralis 384L also uses the same uncooled LWIR microbolometer but with a 384×288 FPA integrated with an eye-safe laser rangefinder as a sight for crew-served weapons.

Information on Chinese developments remains sporadic, although Poly Technologies of Beijing is a known supplier. The company offers the IR 160X series of TWS using an uncooled LWIR Amorphous Silicon detector with a 160×120 FPA on a 25-micron pixel pitch and the IR 161X using the same detector but with a 384×288 FPA, again on a 25-micron pixel pitch. A variant of the latter model, the IR 161E, is offered as a clip-on thermal adjunct to the basic weapon day sight.

It is hoped that this feature (by no means an exhaustive survey of all TWS offerings, merely an overview of the marketplace) has illustrated the way detectors are shrinking in size, while retaining or increasing resolution, as uncooled units are rapidly replacing cooled sights for assault rifle and many crew-served weapons. Of course, the thermal imaging detector is but one variable in the creation of a TWS, optics and display technology being the other prime components. While lower pixel-pitches offer smaller weapon sights, they may not be deemed necessary for other applications. Exactly how small the pixel-pitch can be made without increasing the optics is a debatable subject, to which Battlespace will, no doubt, return at some point in the future.

 

 

 

Back to article list