What is the principle of radar ranging?

The concept of radar was formed in the early 20th century. Radar is the transliteration of English radar, which is the abbreviation of radio. Testing. And ranging, which means that electronic equipment for radio detection and ranging.

The function of radar is similar to eyes and ears, and its information carrier is different from visible light received by eyes, but radio waves. In fact, visible light and radio waves are essentially the same thing, both electromagnetic waves, and the propagation speed is C. The difference between radar and visible light lies in the different frequencies and wavelengths occupied.

The principle is that the transmitter of radar equipment transmits electromagnetic wave energy to a certain direction in space through an antenna, and objects in this direction reflect back when they encounter electromagnetic waves; After receiving this reflected wave, the radar antenna sends it to the receiving equipment for processing, and extracts some information of the object (the distance from the target object to the radar, the change rate of distance or radial speed, azimuth, altitude, etc.). ). Measuring the distance is actually measuring the time difference between the transmitted pulse and the echo pulse. Because electromagnetic waves travel at the speed of light, they can be converted into an accurate distance from the target.