Echo induction is a process in which radio waves are reflected and received again when they hit the object in front. Therefore, the distance between the radar and the target can be calculated from the time from launch to hitting the target, and the size (shape) and moving speed of the target can be judged from the size of the received echo or the strength of the signal.
Infrared scanning imaging. The infrared band is usually defined as 0.76-400 microns. Such a short wavelength forms a radio spectrum that cannot be directly seen by human eyes, that is, infrared spectrum. With the help of infrared spectrometer or infrared imager, people can see the color or image of this band.
The working principle of infrared spectrometer or imager is to scan the infrared wavelength directly on the object, and different parts of the object will have different infrared wavelength scattering. According to the different infrared wavelengths scanned, the image of the object is formed.
After reading the above principle, we can find another difference: radar sensing is a long distance, infrared sensing is generally a short distance, and there is no other means.
The emission of radar waves can easily cross hundreds or even thousands of kilometers, while the direct infrared scanning is hundreds of meters at most, and the most practical application is only a few meters or tens of meters.