How many types of radar are generally classified?

I. There are many kinds of radar, and they are categorized in different ways.

1, according to the radar signal form classification, there are pulse radar, continuous wave radar, pulse compression radar and frequency shortcut radar.

2, according to the angle tracking mode classification, there is a single pulse radar, cone scanning radar and hidden cone scanning radar.

3, according to the parameters of the target measurement classification, there are altimetric radar, two-coordinate radar, three-coordinate radar, and the enemy to know the radar, multi-station radar.

4, in accordance with the technology used by the radar and signal processing methods are phase reference accumulation and military radar non-phase reference accumulation, moving target display, moving target detection, pulse Doppler radar, synthetic aperture radar, scanning and tracking radar.

5, according to the antenna scanning mode classification, divided into mechanical scanning radar, phased array radar.

6, according to the radar band, can be divided into over-the-horizon radar, microwave radar, millimeter wave radar, and laser radar.

Two, radar working principle

Radar plays a similar role and eyes and ears, of course, it is no longer nature's masterpiece FMCW speed and distance principle, at the same time, its information carrier is radio waves. In fact, whether it is visible light or radio waves, in essence, is the same thing, are electromagnetic waves, the speed of propagation in a vacuum are the speed of light C, the difference is that their respective frequencies and wavelengths are different. The principle is that the transmitter of the radar equipment through the antenna to the electromagnetic energy shot in a certain direction in space, in this direction of the object reflecting the electromagnetic wave encountered; radar antenna to receive the reflected wave, sent to the receiving equipment for processing, extracting some information about the object (the target object to the radar distance, the distance from the rate of change or radial velocity, orientation, height, etc.).

The principle of measuring distance is to measure the time difference between the transmitted pulse and the return pulse, because electromagnetic waves travel at the speed of light, according to which they can be converted into the exact distance between the radar and the target.

The principle of measuring target orientation is to utilize the antenna's sharp azimuth beam by measuring the elevation angle against the narrow elevation beam, so that the target height can be calculated based on the elevation angle and distance.

Measurement of speed principle is the radar according to itself and the target between the relative motion generated by the frequency Doppler effect. Radar received target echo frequency and radar transmission frequency is different, the difference between the two is called the Doppler frequency. One of the main pieces of information that can be extracted from the Doppler frequency is the rate of change of the distance between the radar and the target. When the target and the interference noise exist in the same spatial resolution unit of the radar at the same time, the radar can detect and track the target from the interference noise by utilizing the difference in Doppler frequency between them.

Third, radar frequency division