AN/PAS-13B Thermal Weapon Sight

AN/PAS-13(V)1 Light Weapon Thermal Sight (LWTS)

Type Scope/Camera

Place of origin United States

Category Military

Production history Designer Raytheon

Manufacturer Raytheon

Produced 1998 Number built 33,400

Variants Medium and Heavy Specifications

Weight

Medium: 5 pounds (2.3 kg)

Heavy: 5.5 pounds (2.5 kg)

Dimensions(LxHxW)

Medium: 15.8x6.3x6.3 inches

Heavy: 18.11x6.3x6.3 inches

Cont Operation(hrs) 7 hours

Field Of Vision

Medium

Wide: 18x10.8 degrees

Narrow 6x3.6 degrees

Heavy

Wide: 9x5.4 degrees

Narrow: 3x1.8degrees

Range of Detection

Medium

Detect Human: 1.2km

Detect Vehicle: 4.2km

Heavy

Detect Human: 2.8km

Detect Vehicle: 6.9km

System Zoom

Medium 5x

Heavy 10x

The AN/PAS-13B Thermal Weapon Sight (TWS) is an infrared sight developed for the United

States military by Raytheon. The sight is designed for use on small arms in the U.S. military's

inventory, but it can also be used as a standalone observation device. The AN/PAS-13B uses

thermal imaging so that it can be used day or night. Thermal imaging also allows the sight to see

through smoke or fog, things that may normally obscure other night vision devices. The

AN/PAS-13 first became operationally capable with the U.S. Army in 1998 and has reached a

total production of 33,400 units.[1]

[edit] Design and Features

The view through a AN/PAS-13 sight.

Due to the use of thermal imaging, the AN/PAS-13B does not require low levels of light to

operate, and it will not shut off like most night vision if hit directly by light. The thermal imaging

sensor within the sight requires a low temperature to operate, so a cool-down time of less than 2

minutes is required at startup. The AN/PAS-13B comes in two variants, the Medium AN/PAS-

13B(V)2 and the Heavy AN/PAS-13B(V)3. The Medium has a smaller telescope attached,

resulting in a zoom of 5x compared to the Heavy's 10x. Both AN/PAS-13Bs have programmable

reticles, allowing the user to match the reticle to the weapon system the sight will be mounted

on. Some reticles included in the sight include those designed for the M16 Rifle, M4 Carbine,

M60 Machine Gun, M240 Machine Gun, M249, M2 Machine Gun, MK19, M24 Sniper Weapon

System, and the GAU-21. The sight also has a multi-function I/O port, allowing for video to be

recorded or viewed from a location other than the eyepiece. When using the eyepiece, the rubber

cup surrounding the eyepiece must be depressed slightly to engage the display and cooling

mechanism. The image displayed for the user is black and white. The user has the ability to

select whether white or black will represent hotter objects by selecting "black hot" or "white

hot". AN/PAS-13Bs are powered by standard military disposable or rechargeable lithium-ion

batteries.[2]

[edit] New Versions

In November 2006, three new versions of the AN/PAS-13 were ordered by the U.S. military. The

Thermal Weapon Sights II include three new versions, a Light, Medium, and Heavy. All three

models weigh less than the originals, weighing 1.8lbs, 2.8lbs, and 3.9lbs respectively. This

reduction in weight and size is due to improvements in the sensors, as well as the ability to now

run the sights without being cooled. The Medium and Heavy models maintain zooms of 5x and

10x, while the Light model has a zoom of 1.55x and a FOV of 15 degrees. All three models now

run on Lithium AA batteries, with the Light having a battery life of 5 hours, the Medium 6.5, and

the Heavy 6.5.[3]

The US Armed Forces designates version 2 as MTWS (Medium Thermal

Weapon Sight), and version 3 as HTWS (Heavy Thermal Weapon Sight).[4]

Thermal sights on weapons see heat. This has advantages in complete darkness, or in the presence of

obscurants like dust storms, normal smoke, etc. because they can still pick out human and vehicle

targets. Using deep infrared viewers also avoids “blooms” or whiteouts if someone flashes a bright light

source like a flashlight at you. On the other hand, unless the lines on your map or lettering on that street

sign have different heat values, thermal/ “deep infrared” sights aren’t going to help very much. This is

why most 3rd and 4th generation night vision goggles use a combination of thermal and light intensifier

technologies.

The AN/PAS-13 thermal weapons sights are used in more limited capacities, either as weapons sights or

without a weapon as a sort of hand-held “night telescope.” The second generation of these sights is now

being fielded, and are the subject of additional multi-billion orders from the US military.

The new sights use microbolometer thermal imaging technology, which increases their surveillance and

target acquisition range in all weather conditions, while shrinking the sights’ size and weight.

Bolometers measure electric resistance changes with temperature, and their compatibility with

standard CMOS silicon circuits allows for uncooled thermal sights with low cost of production, plus VLSI

(Very Large Scale Integration) ‘active pixel’ architectures that place all camera functions on a single chip.

Because it’s all solid-state electronics, the number of moving parts and hence breakage risks are also

lower than previous generation technologies like “chopper” assemblies.

TWS-II sights also offer a dual field of view via E-Zoom, video output, and electronically programmable

reticles with alphanumeric system information overlaid on the eyepiece display. This family of thermal

weapons sights come in 3 versions. All statistics given are for the TWS-II variants:

AN/PAS-13 (V)1 Light Thermal Weapon Sights (LTWS) for 5.56mm M-16/M4 assault rifles and M136/AT-

4 anti-tank rockets. These sights include features like a 15 degree horizontal field-of-view lens designed

for urban warfare and other wide-view, close-in focus situations.

Target Recognition Range: 550 meters

Weight LWTS: 1.8 pounds

Operational Time: 5 – 25 hours (4 Lithium AAs)

Field of View: 15 degrees

Magnification: 1.55x

AN/PAS-13 (V)2 Medium Thermal Weapon Sights (MTWS) that mount to M249 “Minimi” 5.56mm Squad

Automatic Weapons and M240 family 7.62mm machine guns.

Target Recognition Range: 1100 meters

Weight: 2.8 pounds

Operational Time: 6.5 – 18 hours (6 Lithium AAs)

Field of View: 6 degrees/18 degrees (narrow/wide)

Magnification: 5x/1.66x (narrow/wide)

AN/PAS-13 (V)3 Heavy Thermal Weapon Sights (HTWS) mount to M2 .50 cal heavy machine guns and

MK19 40mm grenade machine guns; and on sniper weapon systems like modified M4/M16s, the

7.62mm M24 sniper rifle, and the .50 cal M107 long range sniper rifle.

Target Recognition Range: 2200 meters

Weight: 3.9 pounds

Operational Time: 6.5 – 18 hours (6 Lithium AAs)

Field of View: 3 degrees/9 degrees (narrow/wide)

Magnification: 10x/3.3x (narrow/wide)

The use of AA batteries, instead of the TWS-I sights’ proprietary military batteries, is a very large and

important change. Even in war zones, AA batteries are often available in local shops, giving units in the

field more options to keep their gear going.

The medium and heavy sights interface with a variety of 26mm, 52mm, 62mm, 103mm, 150mm and

156mm telescopes. Menu-based, push-button controls are used for operating reticle selection and

adjustment, polarity, and brightness, while drop-in upgrades are meant to help ‘future proof’ the sights

by making upgrades simpler.

IOC: 1998

Also Known As: AN/PAS-13C and AN/PAS-13E

Origin: United States of America

Contractor/s: Raytheon

Description: The AN/APS-13 Thermal Weapon Sight is a second generation FLIR for use on rifles,

surveillance missions and shoulder-launched missiles. The PAS-13 can be used to see in total darkness,

in adverse weather conditions, and through battlefield smoke and dust. The TWS provides

interchangeable telescopes for quick adaptation to any mission. It has video output and has been

selected as the sight for the US Army's Land Warrior program.

The combat-proven PAS-13 thermal sight is electronically programmable, requires no visible light to

operate and will not shut down when hit by direct light. It is lightest enough to be hand-held operated.

There are three PAS-13 variants the Light, Medium and Heavy, the LTWS, MTWS and HTWS respectively.

The AN/PAS-13 LTWS can be installed on the M4, M16, M203 and M136 weapons.

Deliveries to the US Army began in 1998 with the Thermal Omnibus contract, with more than 12,500

units already delivered to the US Army, US Marine Corps and Special Operations Forces. In 2004, the US

Army placed four orders (3+1) worth $201 million ($165 million + $36 million) covering deliveries of

11,812 (9,956 + 1,856) in support of US military troops deployments in Afghanistan and Iraq. With the

current contracts, Raytheon will have delivered more than 27,000 light, medium and heavy TWS.

Parent system is the AN/PAS-13 TWS

Total Production: 40,400

Production Cost: USD$563 million

Other Family Members: AN/PAS-13B(2) MTWS and AN/PAS-13B(3) HTWS

Transactions: There are 1 transactions involving 5,000 items for AN/PAS-13 TWS from 2007 to 2012 and

1 transactions involving 1,666 items for the AN/PAS-13 LTWS view report

Performance Max Detection Range: 600 meter

Time Battery Life: 7 hour

Weight Weight: 1.40 kilogram