The difference between low-light night vision and infrared night vision

Low-light night vision technology, also known as image intensification technology, uses night vision goggles with image intensifier tubes. The low-light night vision device uses the low-brightness night sky light, stars, moonlight, atmospheric glow and other natural light reflected by the night target to enhance and amplify it. to hundreds of thousands of times, so as to be suitable for naked eye reconnaissance at night. Low-light technology is an important part of optoelectronic high-tech. In low-light night vision products, the image intensifier is the core device. The image intensifier is used to enhance the weak natural light in the night sky, such as moonlight, starlight, and atmospheric gray light, by hundreds or tens of thousands of times, so that the human eye can perform long-distance operations. degree of observation. Yellow-green light is the wavelength to which the human eye is most sensitive, so fluorescent screens of this color are often used in image intensifiers. When we watch special forces performing night vision imaging in movies and TV, this is why the image in the night vision lens appears yellow-green.

Infrared imaging technology. The principle of infrared night vision is to illuminate the target with an infrared searchlight and receive the reflected infrared radiation to form an image. 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 night vision technology that uses active irradiation and uses the infrared light of the target to reflect the infrared source to observe. The corresponding equipment is an active infrared night vision device. Passive infrared night vision technology is an infrared technology that relies on the infrared radiation emitted by the target itself to achieve observation. It finds the target based on the temperature difference or thermal radiation difference between the target and the background or various parts of the target. Its equipment is a thermal imager. At present, surveillance cameras are equipped with active infrared systems, and there are few applications of passive infrared systems.

Advantages of low-light imaging technology:

The reason why low-light imaging technology is widely used in night vision by the armies of various countries is because of its comprehensiveness. Compared with infrared technology, this technology does not require infrared lamps to emit infrared rays, and the object being observed does not need to have heat, so it is very good. To adapt to the military's operations in different environments, when choosing infrared imaging technology, the first thing to consider is the loss and maintenance of the infrared lamp, and the second thing to consider is whether the object being observed contains heat itself. However, low-light imaging technology does not need to consider so much and only needs to use Natural light can achieve night vision effects. At the same time, low-light night vision devices have clear images, are small in size, light in weight, low in price, easy to use and maintain, not easily susceptible to electronic reconnaissance and interference, and have a wide range of applications. These are incomparable to infrared night vision imaging. of.

Disadvantages of low-light imaging technology:

The disadvantage of low-light imaging technology is that it is affected by the surrounding environment, such as fear of strong light and halo phenomenon. Night vision devices cannot observe when encountering strong light, and the observer will feel dizzy. The contrast of low-light images is poor and gray. The degree level is limited, the instantaneous dynamic range is poor, there is flickering at high gain, and it is only sensitive to the reflection of the target scene and has nothing to do with the thermal contrast of the target scene.

Advantages of infrared imaging technology:

Both active and passive systems do not need to rely on external ambient light. The active system emits infrared rays for night vision imaging. The night vision range is wide, the resolution can reach megapixels, the images can be used for forensics, and it is less affected by the environment because it does not rely on natural light and is suitable for Used in total darkness indoors and outdoors, infrared thermal imaging is not affected by rain, snow, wind, frost, strong light and other harsh environments. It can identify camouflage and resist interference, and has a long detection range. It does not rely on natural light like low-light night vision devices. It relies on the radiation of the target and the background to generate the scene image, so the infrared thermal imaging system can work 24 hours a day to achieve day and night monitoring.

Disadvantages of infrared imaging technology:

The reason is that the infrared image is only sensitive to the radiation of the target scene and is not sensitive to the brightness changes of the scene. The key components of active infrared have a short life and are easily damaged and require maintenance and replacement. Passive infrared thermal imaging requires the temperature of the object and the intensity of infrared rays, which cannot adapt to the monitoring needs in different environments. Moreover, thermal imaging cannot distinguish text and signs, cannot identify license plates and faces, is not sensitive to the surrounding environment, and cannot be worn. Through glass.

From the perspective of scientific and technological development, infrared technology has certain advantages. The existence of visible light is conditional, and any object is an infrared source and is constantly radiating infrared rays, so the application of infrared technology will be everywhere. At present, in terms of close-range night vision, low-light night vision devices still occupy a dominant position due to their low price and good image quality.

Dual-light fusion is a dual-channel "low-light + thermal imager": it uses infrared and low-light technologies to image at different wavelengths, simultaneously detects the two-dimensional geometric space and one-dimensional spectral information of the target, and then uses certain Image processing algorithms analyze and process multi-band images and make full use of useful information in various channels to synthesize images.

Four high-definition imaging modes can be switched at will, four times fused optical zoom, automatic tracking of infrared hot spots, 8-14μm high-sensitivity long-wave infrared imaging, 0.4-1.2μm low-light imaging/2k resolution, infrared and low-light dual-channel fusion, no Shutter thermal imaging, electronic compass, compact and flexible, easy to carry. It can perform imaging reconnaissance in all weather conditions such as night, rain, fog, wind and sand, etc.

With the development of low-light and infrared imaging technology, it has become an effective technical means to synthesize and explore the characteristic information of low-light and infrared images and fuse them into a comprehensive image. Night vision image fusion can enhance scene understanding and highlight Targets are conducive to faster and more accurate detection of targets in hidden, camouflaged and confusing military backgrounds. The fused image is displayed in a natural form suitable for human eye observation, which can significantly improve the recognition performance of the human eye and reduce operator fatigue. sense, and the visual effects are perfectly presented.

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