What is night vision?

Night vision technology is a photoelectric technology that realizes night observation with the help of photoelectric imaging devices. Night vision technology includes low light level night vision and infrared night vision. Low-light-level night vision technology, also known as image enhancement technology, is a photoelectric imaging technology which uses image intensifier tube to enhance the weak target image irradiated by nightglow, and is used for observation through night vision goggles. Low-light-level night vision equipment is the most abundant and widely used night vision equipment abroad at present, which can be divided into direct observation (such as night vision equipment, weapon sight, night pilot and night vision glasses) and indirect observation (such as low-light-level TV). Infrared night vision technology is divided into active infrared night vision technology and passive infrared night vision technology. Active infrared night vision technology is a kind of night vision technology which observes by active illumination and using infrared light reflected by targets in infrared light source, and the corresponding equipment is active infrared night vision device. Passive infrared night vision technology is an infrared technology that realizes observation by means of infrared radiation emitted by the target itself. It finds the target according to the temperature difference or thermal radiation difference between the target and the background or target part. It is equipped with a thermal imager. Thermal imager has unique advantages different from other night vision equipment, such as working in foggy days, rainy and snowy days, working at a long distance, recognizing camouflage and anti-interference. It has become the development focus of foreign night vision equipment, and will replace low-light-level night vision equipment to some extent.