Cats, wolves, foxes, owls, hedgehogs and other living creatures can see well in the dark. It helps them get food, build shelters, find partners for mating and perform other daily activities. However, humans lack night vision, so their eyes can only distinguish nearby objects when darkness falls. In addition, this requires at least some source of light, which is not always possible to access. But man is a brilliant creation of nature. Many years ago, he designed airplanes, cars and ships, thanks to which he learned to fly, quickly cover huge distances on land and swim across oceans. Recently, man has also been able to see generally in poor lighting conditions. For this, he invented night vision and made this technology the most important invention of the last century.
Briefly about night vision technology
People have been striving to see as well as some nocturnal animals for many millennia. However, they only got this opportunity in the middle of the 20th century, when technical progress made it possible to create night vision technology. Before that, all attempts to invent something similar were a failure or allowed only a slight improvement in visibility. This technology opened up new opportunities for humanity and accelerated the development of many areas. With its appearance, people were able to make visible everything that was previously hidden in the dark.
Initially, NV technologies were available only to the military. They were used to gain an advantage over the enemy starting from WWII. After several decades, this technology became available to ordinary people. Further improvement of night vision helped to discover several of its types, which are used in various fields of activity in the 21st century. All of them are rapidly developing and becoming more advanced. In the modern world, NV technologies are in demand wherever you need to see well. With their help, people can perform various actions in conditions of insufficient light and achieve their goals.
Types of NV technologies and how they work
There are three types of NV technologies. All have distinctive features and are becoming popular in different fields of activity. They are united by the ability to create an image that the human eye perceives. Below are the varieties of night technologies and a brief description of their operating principle.
Image intensification
The technology based on image intensification is the most popular worldwide. It is not perfect, but it is incredibly versatile and can cope with hundreds of different tasks. The main disadvantage of devices that support this technology is their low efficiency in complete darkness. However, with at least some light sources (for example, moonlight or starlight), it works well and becomes useful for people of different professions.
The principle of operation is based on image intensification. At the beginning of this process, the lens collects light reflected from objects around the user. Then, it is transferred to the IIT (image intensifier tube). In it, photons of light are passed through the photocathode, where they are converted into electrons. They pass through the microchannel plate, and their number increases. Many electrons rush to the phosphor screen. There, they are instantly converted into photons. Their number becomes more significant than the original, making the image brighter and more transparent. The user can see it through the device’s eyepiece.
Active illumination
NV technology operates on the principle of active illumination. It is more modern than the one that uses image intensification and is considered even more versatile, making it possible to obtain the desired effect even in the complete absence of light. Today, this technology is in demand and suitable for solving most tasks. However, it is not without its drawbacks. This technology uses a unique infrared light source that unmasks the user. Because of this, it is rarely used by soldiers and exceptional services. However, for civilians, this drawback is not so significant.
As mentioned earlier, devices that support active illumination technology operate using an IR illuminator. The illuminator emits a beam of infrared light, which is reflected from surrounding objects and captured by optics. The light then goes to the IIT, undergoing all the same stages as image intensification. At the output, the user receives a distinguishable image in which even minor details can be seen.
Thermal imaging
Thermal imaging is a special type of NV technology that works differently and improves visibility in challenging and extreme conditions. Thanks to its ability to detect heat waves, the user can get a visible picture without any lighting. Thermal imaging is also practical in fog and smoke and can detect heat emanating from camouflaged or hidden objects behind obstacles. This technology is widely used by both military and civilians. It makes it possible to solve any problem and guarantees the accuracy of the results.
The operating principle is based on detecting thermal radiation and its conversion into an image on the screen. To do this, devices that support this technology detect IR radiation emanating from all objects with a temperature above 0 degrees Celsius. Then, it gets to the matrix, where it is converted into an electrical signal. The system processes it, and a thermogram is formed based on the original information. A thermal image is created from it and sent to the display. Each pixel contains temperature information, so the user can easily distinguish hot objects from cold ones.
Applications
Night vision is a popular technology that benefits people and allows them to solve hundreds of problems. Many devices currently support this technology, the most common of which are NV goggles, binoculars and monoculars. Due to their versatility, they become indispensable assistants in different situations. Cameras and sights, although used less often, are also helpful optics when performing some tasks.
NV technologies were created for the military, so they use them most actively. Various optics help soldiers conduct reconnaissance activities, monitor enemy actions in the dark, and safely move in places with poor lighting. Night vision has long been mandatory for most military aircraft, helicopters, ships, and ground combat vehicles.
NV technologies are also in demand among civilians. They are used wherever there is a need to perform various actions at night. In industrial enterprises and construction sites, it increases safety and makes it possible to work around the clock. NV technology helps police officers and security guards monitor the situation, detect violators, identify criminals, etc. Rescuers use it to search for missing people; ecologists use it to assess the state of the environment, and scientists use it to study the behavior of nocturnal animals. This list can be continued indefinitely since night vision will benefit people in almost all professions.
Because night vision hunting is legal in many countries, NV technologies are also popular among fans of this hobby. They help hunters navigate the dark forest, find animals, identify their species, and aim and shoot. Night technologies are no less helpful for fans of hiking. The capabilities of various devices allow you to notice dangers, choose the correct route, monitor the surrounding area, and much more. Those who enjoy camping, birdwatching, and other outdoor activities will also be unable to do without night vision.
Just a few decades ago, people invented night vision technology. Today, it is an indispensable assistant to man and opens up new development opportunities. With a simple principle of operation and many options for use, night vision is quickly introduced into various fields of activity and greatly benefits humanity.
