In addition to the visible light images we are familiar with, objects in nature also have an infrared thermal radiation image, but the human eye cannot see infrared thermal radiation because it emits infrared rays, which are invisible light.

Today, a magical technology called "infrared thermal imaging" can convert thermal radiation images into visible light images, which allows people to see things that were invisible in the past. The device that realizes this conversion is called a thermal imager. Through this thermal imager, we can see the scene like daytime in the dark night.

Now let's take a look at how the thermal imager completes this conversion. The optical scanning mechanism decomposes the thermal radiation image of the scene received by the infrared telescope into thermal radiation signals and focuses them on the infrared detector. The detector and the image video system amplify the thermal radiation signal and convert it into a video signal. People can see magical pictures through the display. The thermal imager can identify tiny differences in temperature within a few hundredths of a degree Celsius.

Thermal imaging technology is based on the fact that all objects generate heat. Although many objects cannot be seen from the outside, there is still a distinction between hot and cold. With the help of the colors on the heat map, we can see the temperature distribution. Red and pink represent relatively high temperatures, while blue and green represent relatively low temperatures.

Thermal imaging technology has been used in the military since World War II. Since this instrument, the infrared thermal imager, works by thermal radiation, it can allow soldiers to clearly see the enemy's whereabouts through the dark battlefield. And because it is a passive receiving system, it is safer and more concealed than visible light devices such as radio radar.