Night vision system

A night vision device (NVD), also known as night optical/observation device (NOD) and night vision goggles (NVG), is an optoelectronic device that allows images to be produced in levels of light approaching total darkness. The image may be a conversion to visible light of both visible light and near-infrared, while by convention detection of thermal infrared is denoted thermal imaging. The image produced is typically monochrome, e.g. shades of green. NVDs are most often used by the military and law enforcement agencies, but are available to civilian users. The term usually refers to a complete unit, including an image intensifier tube, a protective and generally water-resistant housing, and some type of mounting system. Many NVDs also include optical components such as a sacrificial lens, or telescopic lenses or mirrors. An NVD may have an IR illuminator, making it an active as opposed to passive night vision device.

Night vision devices were first used in World War II and came into wide use during the Vietnam War. The technology has evolved greatly since their introduction, leading to several "generations" of night vision equipment with performance increasing and price decreasing. Consequently, they are available for a wide range of applications, e.g. for gunners, drivers and aviators.

The classification below was initially introduced by the US manufacturers through the US government. Other manufacturers do not abide by it.

In 1929, Hungarian physicist Kálmán Tihanyi invented the infrared-sensitive (night vision) electronic television camera for anti-aircraft defense in the UK.

The first military night vision devices were introduced by the German Army as early as 1939, and were used in World War II. AEG started developing the first devices in 1935. In mid-1943, the Army began the first tests with infrared night-vision (Nachtjäger) devices and telescopic rangefinders mounted on Panther tanks. Two different arrangements were created and used on Panther tanks. The Sperber FG 1250 ("Sparrow Hawk")), with range up to 600m, had an 30 cm infrared searchlight and an image converter operated by the tank commander. This was matched by an earlier experimental Russian version dubbed the PAU-2 and was field tested in 1942. From late 1944 to March 1945, there were some successful tests of FG 1250 sets mounted on Panther Ausf G tanks (and other variants). By the end of World War II, approximately 50 (or 63) Panthers had been equipped with the FG 1250, and saw combat on both the Eastern and Western Fronts. The "Vampir" man-portable system for infantry was used with Sturmgewehr 44 assault rifles. Parallel development of night vision systems occurred in the US. The M1 and M3 infrared night sighting devices, also known as the "sniperscope" or "snooperscope", were introduced by the US Army in World War II, and also used in the Korean War, to assist snipers. These were active devices, using a large infrared light source to illuminate targets. Their image intensifier tubes used an anode and an S-1 , made primarily of silver, cesium, and oxygen, and electrostatic inversion with electron acceleration was used to achieve gain.

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