Night vision device

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 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.… beginning in 2001, the US implemented a new figure of merit (FOM) system for determining the release of night vision technology. FOM is an abstract measure of image tube performance, derived from the number of line pairs per millimeter multiplied by the tube's signal-to-noise ratio. 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 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. A retrospective classification of NVDs into 'generations' was initially introduced by US manufacturers, through the US government. Under this periodization, the period prior to the end of World War II has sometimes been described as 'Generation 0'. In 1929, Hungarian physicist Kálmán Tihanyi invented an infrared-sensitive 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 German Army began the first tests with infrared night-vision (German: 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 600 m, had a 30 cm infrared searchlight and an image converter operated by the tank commander.