What is radar?

Radar is an electronic device that uses electromagnetic waves to detect targets.

The radar emits electromagnetic waves to illuminate the target and receives its echoes, thus obtaining information such as the distance from the target to the electromagnetic wave emission point, the rate of change of distance (radial speed), azimuth, altitude and so on. Various radars have different specific uses and structures, but their basic forms are the same. Comprises a transmitter, a transmitting antenna, a receiver, a receiving antenna, a processing part and a display, and auxiliary equipment such as power supply equipment, data recording equipment and anti-interference equipment.

Radar functions like eyes and ears. Of course, it is no longer a masterpiece of nature, and its information carrier is radio waves. In fact, visible light and radio waves are essentially the same thing, both electromagnetic waves, and the propagation speed in vacuum is the speed of light C. The difference lies in their respective frequencies and wavelengths. Its principle is that the transmitter of radar equipment emits electromagnetic wave energy to a certain direction in space through an antenna, and the object in this direction reflects the electromagnetic wave it encounters.

Radar classification

There are many kinds of radars, and the classification method is also very complicated. It's usually military radar. Generally speaking, radars can be classified according to their uses, such as early warning radar, search warning radar, guidance and command radar, artillery aiming radar, altimeter radar, battlefield surveillance radar, airborne radar, radio altimeter radar, radar fuze, weather radar, air traffic control radar, navigation radar, collision avoidance radar and friend-or-foe identification radar.

1, divided into pulse radar, continuous wave radar, pulse compression radar and frequency agile radar according to radar signal forms.

2. According to the angle tracking methods, there are monopulse radar, conical scanning radar and hidden conical scanning radar.

3. According to the parameters of target measurement, there are altimeter radar, two-coordinate radar, three-coordinate radar, friend or foe identification radar and multi-station radar.

4. According to radar technology and signal processing methods, there are coherent accumulation and incoherent accumulation, moving target display, moving target detection, pulse Doppler radar, synthetic aperture radar and tws radar.

5. According to the antenna scanning mode, it is divided into mechanical scanning radar and phased array radar.

6. According to the radar frequency band, it can be divided into over-the-horizon radar, microwave radar, millimeter wave radar and lidar.

Refer to the above content: Baidu Encyclopedia-Radar