AN/PVS-4

The Sight, Night Vision, AN/PVS-4 is a portable, battery-operated, GEN II Image Intensified device used
for observation and aimed fire of weapons at night. It amplifies reflected light such as moonlight, starlight, and
skyglow so that the viewed scene becomes visible to the operator. The AN/PVS-4 can be tripod-mounted for
surveillance; however, it is generally used as a weapon sight.
TECHNICAL CHARACTERISTICS
MAJOR COMPONENTS
Qty Item Qty Item
-1 Case, Carrying 1 Mounting Bracket Assembly
- 1 Reticle Cell Assembly
- 1 Low Temperature Adapter Assembly
- 1 Cover, Daylight
ASSOCIATED COMPONENTS: Bag, Carrying - Batteries
Specifications: Magnification 5.6X - Field of View 9 deg - Eyepiece Focus +3 to -6 diopters - Objective Lens Focus 25 m to infinity - Range 1,093 to 1,312 yd (1,000 to
1,200 m) (for vehicle targets) - in starlight or moonlight - Reticle Adjustment ±2.5° (1/4-mil increments) - Operating Conditions -65°F to +125°F (-54°C to +52°C) - Battery Type: BA-5567/U, AA or Lithium available(two needed) - Voltage 3.0 VDC - Shelf Life 1 year at 70°F (21°C) - Operating Life 50 hours at normal room temperature

Mini Night Sight

The AN/PVS-17 Mini Night Sight (AN-PVS-17B, AN/PVS-17C) is a lightweight, compact, high performance device that uses a Gen 3 MX-10160-style
image intensifier tube without manual gain control. The system weighs less than 2 pounds, comes with a MIL-STD-1913 rail grabber interface,
and is immersible to 66 feet. The AN/PVS-17 consists of two configurations: AN/PVS-17B and AN/PVS-17C. The
17B incorporates a 2.25X magnification and the 17C incorporates a 4.5X magnification. The AN/PVS-17 can be
mounted to any weapon that uses the standard MIL-STD-1913 rail and will replace the AN/PVS-4 in select units.
The 17B is intended for mount on the M16 Series and the 17C is intended for mount on the M249 Squad Automatic
Weapon (SAW) and M240G Medium Machine Gun.
TECHNICAL CHARACTERISTICS

Magnification:
17B 2.25X ± .15X
17C 4.5X ± .3X
Field of View:
17B 17 deg vertical, 20 deg horizontal
17C 10 deg vertical, 8 deg horizontal
Objective Focus Infinity
Eyepiece Focus +3 to -3 diopters ±1
Battery Type AA Alkaline (one needed) or
Lithium, 1.5 or 3.6 V (one needed)
Reticle Dot Size 0.6 mrad (2 MOA) 17C
0.3 mrad (1 MOA) 17B
Temperature Range:
Operating -40ºF to +125.6ºF
(-40ºC to +52ºC)
Storage -59ºF to +159.8ºF
(-51ºC to +71ºC)
Maximum Altitude 45,000 ft (13,716 m)
Maximum Immersion
2 atmosphere seawater 66 ft fresh water
Height: 17B 4.75 in. (12.06 cm)
17C 4.75 in. (12.06 cm)
Width: 17B 3.0 in. (7.62 cm)
17C 3.25 in. (8.25 cm)
Weight: 17B 2 lb (.97 kg)
17C 3 lb (136 kg)MAJOR COMPONENTS
Qty Item Item
1 Case, Soft Carrying M16 Mounting Kit
ASSOCIATED COMPONENTS: Bag, Carrying - Battery, AA Alkaline, 1.5 VDC

Night Vision Generations and Marketing Mis-Use

Sowing Confusion for Customers

Current night vision technology is only made up of Gen 0, Gen 1, Gen 2, and Gen 3 night vision image intensifiers. Gen 4 is a mis-nomer and a mis-leading use of the US Army's Night Vision Directoriate nomenclature. Gen 4 simply does not exist and is used as a marketing term to confuse customers by several internet night vision firms. The original Litton / Northrop Grumman / L-3 unfilmed image intensifiers were known as Gen 4 for a brief period of time, but this designation was withdrawn by the Night Vision Directoriate quickly after first-use. Simply put, US Manufactured Gen 3 is the best you can get. There are variations of Gen 3, such as thin-filmed, unfilmed, auto-gated tubes for example, but if someone pushes you to go to Gen 4 - head for the door!

Fusion Technology - Best of Thermal, IR and Night Vision

How Night Vision Works

The US Army’s Image Intensification program grew out of the near infrared imaging tube development activity.  During 1955 – 1958, in-house systems analyses and visual human factor studies resulted in the development of techniques permitting the prediction of detection and target recognition performance of electro-visual devices in general.  These studies continued to indicate that cascade image tubes and intensifier image orthicons were the most promising intensifiers for military use.

After a profound effort on the part of industry and staff members of the Night Vision and Electronic Sensors Directorate, the development of the first generation imaging tube was completed by early 1965 and the production phase initiated. This resulted in the availability of passive night vision systems in the Southeast Asia Theatre.

The first-generation image intensifier devices represented a major advance in night vision military technology:  A soldier could now conduct his combat missions without any active illumination sources using only image intensifiers.

Image intensifiers capture ambient light and amplify it thousands of times electronically to display the battlefield to a soldier via a phosphor display such as night vision goggles.  This ambient light comes from the stars, moon or sky glow from distant manmade sources, such as cities. 

The image, below, illustrates the process whereby an image intensifier system amplifies a low level input image with spatial coherence and displays a high level output to the observer.  The system consists of a front-end objective, an image intensifier tube and a display eyepiece.

The dim image is focused on the photocathode of the image intensifier tube which consists of 3 single-stage image-converter tubes each fiber optically coupled to each other.  The photo-electronic image is accelerated by an electric field.  The resulting electron energy is transferred to a luminescent screen and converted to light.  The process is repeated in the second and third stages increasing the light gain resulting in a resolution which can vary between 20 and 23 line pairs/mm.

The first-generation family of night vision devices consisted of three systems: the following

• The Starlight Telescope
• Crew Served Weapon Sight
• Night Observation Device

NITEHOG night vision weapon scopes are manufactured to very strict standards. Performance measurements are listed for specific target acquisition and detection using NATO-standard performance charts and calulations. These sights provide superior imaging capability in environments where night vision cannot perform. NITEHOG thermal and infrared products are precision electro-optical instruments and are available to local, state and federal agencies as well as all branches of the United States Military. They are also available to US citizens for purchase within the United States. All systems are subject to strict compliance with all relevant laws and export restrictions.

Night Vision Imaging in the US Military

Well known for the development of the “night vision goggles,” the Army Materiel Command (AMC) Research Development and Engineering Command (RDECOM), Communications-Electronics Research Development and Engineering Center’s (CERDEC) Night Vision and Electronic Sensors Directorate (NVESD) does more than just make goggles.

History

Early Attempts at Night Vision Technology

Historically, military tacticians have benefitted from the ability to maneuver under the cover of darkness. However, military maneuvers were rarely conducted at night because it was so risky.

During WWII, the United States, Britain, and Germany developed a rudimentary infrared sniper scope that used near-infrared cathodes coupled to visible phosphors to provide a near-infrared image converter to begin night fighting efforts. Though approximately 300 of these Sniperscopes were shipped across the Pacific in 1945, few were used. With a range of less than 100 yards, they could only provide perimeter defense. These limited range, rifle-mounted scopes ran off of cumbersome batteries and required active IR searchlights so large that they had to be mounted on flatbed trucks. This searchlight could readily be detected by enemy soldiers with similar equipment.

Despite its inadequacies, this infrared Sniperscope initiated investigation into advanced night vision technology. Military leaders saw many uses for such technology beyond sniping under the cover of darkness. There was potential for night vision goggles, helmets, and weapon sights to equip armies to operate 24 hours a day. The next challenge in night vision technology would be developing passive systems without IR searchlights, that would no longer betray a soldier's position to the enemy.
Establishing the Night Vision and Electronic Sensors Directorate (NVESD)

The Night Vision and Electronic Sensors Directorate (Night Vision) dates back to 1954 with the founding of the Research and Photometric Section of the Corps of Engineers Engineering Research and Development Laboratories (ERDL). ERDL began with minimal funding and without laboratory facilities. The Research and Photometric Section began developing personalized night vision equipment intended for use by individual soldiers in the field, which carved a unique niche for ERDL: many similar organizations were developing large weapons systems.

The initial mission of Night Vision was "the Conquest of Darkness so that the individual can observe, move fight, and work at night by using an image that he can interpret without specialist training and to which he can immediately respond". As Night Vision expanded into new areas and across Army platforms, this objective expanded to discover new applications for its sensor technology.
Early Areas of Night Vision Research and Accompanying Challenges

The 1940s and 1950s
Soldier With Early Model Scope
Soldier With Early Model Scope

Through the 1940s and 1950s, Night Vision focused on improving the cascade image tube, developed in Germany during WWII. Night Vision contracted scientists from the Radio Corporation of America (RCA) to research and develop a near-infrared, two-stage cascading image tube. This new cascade image tube, which used a multi-alkali photocathode, exceeded expectations. The Image Intensification (I2) system collected and intensified ambient light from the night sky. Night Vision began improving the system, which, while innovative, presented challenges limited light gain and inverted images. To remedy these issues, a third electrostatic stage was added to enhance light gain and to re-invert the image. With this, however, the tube grew to 17inches in length and 3.5inches in diameter; too large for practical applications.

From 1957-1958, John Johnson, a Night Vision scientist, worked to develop methods of predicting target detection, orientation, recognition, and identification. Johnson worked with volunteer observers to test each individual's ability to identify targets through image intensifier equipment under various conditions. Thus, the 1950s also marked a noted development in the performance modeling of night vision imaging systems.

In October of 1958, at the first Night Vision Image Intensifier Symposium, Johnson presented his findings in a paper entitled, "Analysis of Image Forming Systems". The paper described image and frequency domain approaches to analyzing the ability of observers to perform visual tasks using I2. The findings presented became known as the Johnson Criteria and proved to be hugely important in understanding the performance of and guiding further development of night vision devices and systems.

Examples of night vision technology fielded in the 1940's and 1950's include:

1940s - Sniperscope
1940s - Metascope
1955 - First NIR Mapper
1958 - First IR Linescanner

The 1960s

During the mid-1960s, Night Vision scientists and engineers fielded the first generation of passive night vision devices for U.S. troops, including a Small Starlight Scope. These systems were referred to as the First Generation Image Intensifiers. Second and third generations have since evolved.

Also during this decade, to pursue Research and Development (R&D) objectives, Night Vision worked and contracted with scientists and engineers from other organizations. Night Vision advanced beyond acting solely as a research institution to coordinating and managing further shared research initiatives in many fields including astronomy, nuclear physics, and radiology and continued to work with research personnel from leading commercial organizations. This collaboration with private industry became one of Night Vision's fundamental strategies in technology development.

Vietnam

The First Generation Small Starlight Scope was soon used in the field. As the United States became increasingly involved in the Vietnam War, U.S. soldiers recognized that the enemy relied on the cover of darkness to conceal its offensive operations. In 1964, the U.S. Army issued night vision equipment to its deployed troops: The War became a driving force in further technology development.

Personnel from Night Vision traveled to Vietnam to evaluate fielded equipment and interviewed U.S. soldiers and Vietnam veterans to collect user feedback. Gaining real-time, first-hand knowledge from Warfighters became a hallmark of Night Vision's R&D technique and was later especially useful in assessing soldiers' needs during Operation Desert Storm. Regarding this approach, Dr. Robert Wiseman, former head of Night Vision noted soldier reports that, "You don't know how many lives you've saved."

On November 2, 1965, the Night Vision Laboratory (NVL), the precursor of Night Vision and Electronic Sensors Directorate (NVESD), was established to consolidate the several areas of night vision research under a single organizational director, Dr. Robert S. Wiseman. The areas of research for which NVESD was then officially responsible were Visionics & Image Intensification, Far-Infrared, Light Source, Thin Film, Advanced Developments, Systems Development, and Systems Evaluation.

Subsequent to this unification, there was an R&D organization on Fort Belvoir dedicated to studying night vision technology. NVL expanded its R&D efforts and began to make new discoveries in various fields, including lasers and battlefield sensors. It took on the 'official' name of Night Vision and Electronic Sensors Directorate (NVESD) to better encompass all areas of research.

Night vision equipment fielded in the 1960s included:

1964 – Starlight Scope
1965 – TVS-4 Night Observation Device
1967 – Low Light Level Television; Pulse Gated I2-TVS-2 Crew Served Weapon Night Sight
1969 – First Laser Rangefinder (Ruby); PSS-11 Handheld Metallic Mine Detector

The 1970s

Thermal imaging, based on the far infrared spectrum, forms an image of objects by sensing the differences between heat radiated by an object or target and its surrounding environment. Before the 1970s, prototypes using this technology were very expensive.

While Night Vision R&D focused much of its effort on developing practical night vision equipment based on near-infrared technology, scientists also worked toward technological advancements that would pave the way to far-infrared night vision equipment. The advent of linear scanning imagers, consisting of multiple-element detector arrays, led Night Vision to develop thermal imaging systems in the 1970s. Multiple-element arrays provided a high-performance, real-time framing imager that could be practically applied to military use. This technology led to targeting and navigation systems known as Forward Looking Infrared Systems (FLIR). FLIR Systems provide the advantage of 'seeing' at night as well as through smoke, fog, and other obscuring conditions.

FLIR imaging was in high demand for all weapons system platforms, which spurred a proliferation of designs and prototypes for multiple platforms. To satisfy this demand, a group of experts from Night Vision designed a Universal Viewer for Far Infrared in 1973 that led to the family of Common Modules fielded by thousands across multiple platforms. The Common Module-based FLIR systems were less expensive to purchase and produce than previous designs.

Laser Research

In 1978, the Optical Radiation Technical Area, a group of laser scientists and engineers moved from Fort Monmouth, NJ to the Night Vision Laboratory in Fort Belvoir, VA. At Fort Belvoir, they designed and fabricated some of the first monolithic linear laser diode arrays for operation at room temperature for high peak power laser illuminators. They developed a complete pulsed laser system that operated at 500 watts per pulse at 15 KHz. This compact laser imaged targets up to 3 km away.

Night Vision's laser efforts expanded to include solid state laser R&D, gas lasers, laser radar, chemical detection, lager rangefinder systems, light aiming systems, and laser designator systems. Later, the laser team began working on diode pumped lasers for Army applications. Considerable effort was devoted to tunable lasers for optical countermeasures using various solid state laser materials and nonlinear frequency conversion techniques.

Night vision accomplishments in the 1970's include:

1971 - Handheld Thermal Viewer; FLIR Production; PRS-7 Handheld Non-Metallic Mine Detector
1975 - PVS-4 Individual Weapon Sight; Night Vision Thermal Model Publication
1976 - Common Module FLIR Production
1977 - PVS-5 Night Vision Goggles

The 1980s
Jeep visible with FLIR
Jeep visible with FLIR

In the 1980s Night Vision began improving its Image Intensification systems. The third generation of night vision based on image intensification technology, composed of the AN/AVS-6 Aviators Night Vision Imaging System (ANVIS) and the AN/PVS-7 Night Vision Goggles, was fielded.

In 1980, NVESD developed the AN/GVS-5 Laser Infrared Observation Set, which significantly increased the probability of hitting stationary or airborne targets with the first round fired. Fielded in 1988, the AN/AAS-32 Airborne Laser Tracker greatly improved the offensive capability of Army helicopters.

Night Vision also developed Generation II FLIR by improving its thermal imaging technology. Improved sensor resolution and sensitivity coupled with reduced exposure time through signal processing for aided target detection and recognition led to Generation II FLIR with greater stand-off range.

Also in the 1980s, Night Vision pioneered the revolution in aided target recognition. While U.S. forces now had the ability to see in the dark, improvements were still necessary to help soldiers distinguish between friend and enemy. By uniting with private industry scientists, Night Vision helped develop algorithms that were more effective at detecting targets and minimized false alarm confusion.

Accomplishments during the 1980s:

1981 - VGS-2 Tank Thermal Sight
1982 - TAS-6 Night Observation Device, Long Range
1984 - AVS-6 ANVIS Goggles, 3rd Gen I2
1986 - GVS-5 Laser Rangefinder
1987 - PVS-7 Night Vision Goggles
1988 - AAS-32 Airborne Laser Tracker

The 1990s

In the 1990s, Night Vision developed an eyesafe laser rangefinder, the AN/PVS-6 Mini Eyesafe Laser Infrared Observation Set (MELIOS). The 1990s also saw the next generation of Aviators Night Vision Imaging System with Heads-Up Display (AN/AVS-7) and an improved group of lightweight thermal weapon sights for ground troops.

During the 1990s, Night Vision pioneered the concept for Horizontal Technology Integration (HTI), a new method of developing and acquiring equipment for the U.S. Army. This system focused on developing equipment that integrates FLIR subsystems from a single Project Manager across several weapon systems. This use of common hardware reduced equipment procurement costs.

Desert Storm

The major test of Night Vision's technological efforts came in late 1990/early 1991 when Iraqi armed forces invaded Kuwait. The United States and its allies immediately mobilized to force Saddam Hussein's troops out of Kuwait during Operation Desert Storm. Night Vision systems proved vital to operating in the desert environment. As General Barry McCaffrey, then commander of the 24th Infantry Division, testified: "Our night vision capability provided the single greatest mismatch of the war."

Night Vision systems using I2 and FLIR technologies were used by ground troops on major weapons systems including tanks, helicopters, missile systems, and infantry fighting vehicles. Targeting systems equipped with FLIR technology that could 'see through' dense smoke, dust, fog, and haze at great distances were crucial to the major weapon systems as in Vietnam, Operation Desert Storm showed Night Vision scientists and engineers a way to improve technology by integrating I2 and FLIR capabilities.

Laser Research in the 1990s

In the 1990s, work continued on compact solid state lasers, multifunction lasers, chemical and biological agent detection, and laser radar. Laser system development was also pursued with Night Vision on rangefinders, designators, and laser radar for target identification and obstacle avoidance.

Uncooled IR Sensors for Military Applications

Continuing in its tradition of cooperative R&D, Night Vision works with nongovernment companies to develop uncooled IR sensors and uncooled focal plane arrays sufficient for rifle sights, crew served weapons, driving aids and missile seekers have been demonstrated. This technology has also been transitioned to engineering development and production programs. Looking to the future, uncooled technology should lead to exciting new concepts, to include IR goggles and low cost missile seekers. Networked arrays of miniature, low-cost, light-weight, low-power IR sensors provide exciting new possibilities for sensors to support the Army's vision by providing situational awareness. Larger arrays of uncooled imaging systems offer affordable integration of sensors on robotic, air, and ground platforms.

By the end of the 20th century, NVESD had provided the Army the legacy to "Own the Night". NVESD has transitioned the unique sensor technologies that have resulted in fielding over 400,000 Image Intensifier Systems; 60,000 Thermal Systems; 40,000 Laser Systems; and 15,000 Countermine systems.

21st Century

RDECOM CERDEC NVESD is strongly focused on the Army Vision for the Transformation of the Current to the Future Force. In order to provide the technology transition resulting in superior tactical sensors for tomorrow’s Warfighter, Night Vision’s mission is to:

• Conduct Research and Development to Provide US Land Forces with Advanced Sensor Technology to dominate the 21st Century Digital Battlefield;
• Acquire and Target Enemy Forces in Battlefield Environments;
• Detect and Neutralize Mines, Minefields, and Unexploded Ordnance; Develop Humanitarian Demining Technology;
• Deny Enemy Surveillance & Acquisition through Electro-Optic, Camouflage, Concealment, and Deception Techniques;
• Provide for Night Driving and Pilotage; and
• Protect Forward Troops, Fixed Installations and Rear Echelons from Enemy Intrusion.

Night Vision Terminology

Automatic Brightness Control (ABC) - An electronic feature that automatically reduces voltages intensifier tube to keep brightness within optimal limits and protect from damage.

Blooming - Momentary loss of the night vision image due to intensifier tube overloading by a bright light source. When such a
bright light source comes into the night vision device's view, the entire night vision scene becomes much brighter, "whiting out"
objects within the field of view. Blooming is common in Generation 0 and 1 devices.