What are the main types of radar?

Classification of radar: [1] Coastal defense radar is used for coastal defense detection and coastal defense weapon control. It is an integral part of the command and control system of coastal defense operations. Including coastal warning radar, shore-to-ship missile guidance radar and coastal gun aiming radar. It has a good ability to resist the interference of waves and clutter. Its installation forms are fixed and mobile. Fixed installation in permanent fortifications or suspended by balloons; Motor mounted on the vehicle. Coastal warning radar is generally set in the highlands of the coast and islands to increase the detection distance of sea surface and low-altitude targets. [2] Ballistic missile tracking radar is a long-range tracking radar. It is used to track intercontinental missiles, medium-range missiles and submarine ballistic missiles, continuously determine their coordinates and speeds, identify true and false warheads, accurately predict their future positions, determine their orbits, and guide their own anti-ballistic missiles to attack targets. It is also used for range measurement and identification of ballistic missile testing. It is an indispensable part of anti-missile weapon system and shooting range measurement system. [3] A long-range search radar in ballistic missile early-warning radar. It is used to find intercontinental, medium-range and submarine-launched ballistic missiles, measure their instantaneous position, speed, launching point and landing point, and provide information on ballistic missile attacks for national military command organs. It is also used to undertake the tasks of space surveillance and cataloguing aircraft such as artificial earth satellites. [5] Air intelligence radar is a radar that searches, monitors and identifies air targets and determines their coordinates and motion parameters. Also known as air search radar. The information it provides is mainly used to issue air defense warnings, guide fighters to intercept enemy planes and indicate targets for air defense weapon systems, and also to ensure flight training and flight control. It is an important technical equipment to obtain air target information in modern warfare. [6] Airborne Radar The general term for all kinds of radars installed on aircraft. It is mainly used to control and guide weapons, conduct aerial vigilance and reconnaissance, and ensure accurate navigation and flight safety. The basic principle and composition of airborne radar are the same as those of other military radars. Its characteristics are: generally, there are antenna platform stabilization systems or data stabilization devices; Usually use a belt below 3 cm; Small size and light weight; It has good shockproof performance. It can be divided into: ② Bombing radar, which is mainly used to provide target information for aiming bombing, guiding air-to-ground missiles and piloting. It can work alone, or it can be used with optical sight and computer to form a bombing aiming system. Bombing radar can be divided into forward-looking and panoramic (also called panoramic) according to the search method. The antenna beam of forward-looking radar points to the lower front of the aircraft carrier and searches in the sector area. The antenna beam of panoramic radar is fan-shaped and points to the lower part of the carrier for circular search. It has two working states: searching and aiming. When searching, the antenna performs a circular scan. When the target on the display screen enters the aiming area, the radar turns to the aiming state, sends the measured target data to the computing device, and marks the landing point with other parameters and displays it on the display. When the target signal coincides with the bombing mark, the bombing command is issued to realize automatic bombing. The range of bombing radar is generally 150 ~ 300 km, and the azimuth resolution is about 1 ~ 3. (3) The aerial reconnaissance and terrain display radar is used to provide the position and terrain data of fixed targets and moving targets on the ground (sea surface). Usually it is a side-looking radar with high resolution. Its antennas are installed on both sides of the fuselage, and the beam points to the left and right of the carrier-based aircraft and is perpendicular to the route, and scans forward with the flight of the carrier-based aircraft (Figure 2 is the working schematic diagram of the airborne side-looking radar). Side-looking radar can be divided into real aperture side-looking radar and synthetic aperture side-looking radar. The antenna of the real aperture side-looking radar is 8 ~ 10 meters along the longitudinal direction of the fuselage, forming extremely narrow beams on both sides of the aircraft fuselage, and the resolution is about 10 times higher than that of the panoramic radar. The actual size of the antenna of synthetic aperture side-looking radar is not large, but it uses the forward motion of the carrier and stores and processes the coherent signals to obtain the antenna aperture with an effective length of several kilometers, thus greatly improving the radar resolution (up to several meters). The definition of topographic map obtained by this radar is close to that of aerial photography. Side-looking radar can carry out aerial reconnaissance and terrain display day and night, and can find targets within one or two hundred kilometers of the other side without flying over the other side's position. (4) Navigation radar is used to observe the meteorological conditions, air targets and terrain features in front of the aircraft to ensure the accurate navigation and flight safety of the aircraft. There is a kind of navigation radar specially used to ensure the safety of aircraft flying at low altitude and ultra-low altitude, called terrain following radar and ground object avoidance radar, which are usually installed on aircraft performing low-altitude penetration tasks. Terrain following radar cooperates with computer and flight control system to control the change of flight altitude with terrain fluctuation, so that the aircraft can always maintain a certain safe altitude. The ground object avoidance radar displays the distribution of ground obstacles at a selected altitude for pilots, provides avoidance signals, and enables aircraft to bypass obstacles and ensure flight safety. By using the work transfer switch, the above two radars can be used alternately. There is also a navigation radar specially used to measure the drift angle and ground speed of aircraft, called Doppler navigation radar, which can provide the data needed for navigation and bombing, and is usually installed on bombers and transport planes. ⑤ Airborne early warning radar is the main electronic equipment of early warning aircraft, which can be used for air early warning, command and guidance, and also for air traffic control. It has become an important part of modern air defense system. Compared with ground-to-air intelligence radar, the blind area is small, the distance between low-altitude and ultra-low-altitude targets is long, and the maneuverability is strong. Development trend: China People's Liberation Army began to equip airborne radar in 1950s, and designed and developed monopulse airborne interception radar and bombing radar in 1960s. In 1970s, airborne radars with various systems and functions were developed. With the development of electronic technology and the constant change of tactical requirements, airborne radar will further develop in the range, target resolution and recognition, anti-jamming and reliability. Airborne phased array radar can search and track multiple targets, and has many functions, so it will be widely used. The miniaturization, automation and adaptability of airborne radar will also be further improved. [7] Shipborne radar is the general name of all kinds of radars equipped on ships. It is used to detect and track sea and air targets, provide target coordinates and other data for weapon systems, guide carrier-based aircraft to fly and land, and ensure the safe navigation and tactical maneuver of ships. Development trend: develop multifunctional radar, improve radar efficiency and reduce the number of airborne radars; Further improve anti-jamming ability, suppress sea clutter, overcome low-altitude multipath effect, and improve low-altitude detection and tracking performance. [8] Military radar uses electromagnetic waves to find targets and determine their position, speed and other characteristics. The word "radar" is a transliteration of English radar (abbreviation of radio detection and ranging), which originally meant radio detection and ranging. Radar has the characteristics of long distance to find the target, fast speed to determine the target coordinates and all-weather use. Therefore, it is widely used in vigilance, guidance, weapon control, reconnaissance, navigation support, meteorological observation, friend or foe identification and so on, and has become an important electronic technology and equipment in modern warfare. Mainly include: ① gun aiming radar. It is used to continuously measure the real-time data of target coordinates, and the gun is controlled to aim and shoot through the shooting director. There are land types and ship types. ② Missile guidance radar. It is used to guide and control the flight of various tactical missiles. There are land types and ship types. (3) Torpedo attacks radar. Installed on torpedo boats and submarines, it is used to determine the target coordinates and control the torpedo attack through the director. ④ Airborne interception radar. It is installed on fighter planes to search, intercept and track air targets, and control the aiming and shooting of cannons, rockets and missiles. ⑤ Airborne bombing radar. Installed on the bomber, it is used to search and identify ground or sea targets and determine the release position. ⑥ Terminal guidance radar. Installed on the missile, it automatically controls the missile to fly to the target at the end of the missile flight. ⑦ Ballistic missile tracking radar. In the measurement of anti-missile weapon system and missile range, it is used to continuously determine the coordinates and speed of ballistic missiles in flight and accurately predict their future positions. Radar used for reconnaissance mainly includes: ① battlefield reconnaissance radar. Army reconnaissance troops are used to detect and monitor enemy personnel and vehicles on the battlefield. (2) Gun position reconnaissance and shooting calibration radar. Ground artillery is used to detect the position of enemy artillery firing position and determine the coordinates of its own impact point, so as to correct artillery firing. ③ Moving target reconnaissance and shooting calibration radar. It is used to determine the moving target on the ground or sea surface, determine the explosion point of the shell or the deviation between the water column and the target, so as to correct the shooting of the ground gun or the shore gun. ④ Reconnaissance and terrain display radar. Installed on aircraft, it is used to detect moving targets and fixed targets on the ground and at sea, and draw topographic maps. It uses a synthetic aperture antenna with high resolution; The definition of the obtained terrain image is close to that of optical photography. The radars used for navigation support mainly include: ① navigation radar. Installed on an airplane, it is used to observe the meteorological conditions, air targets and terrain features in front of the airplane to ensure the safe flight of the airplane. ② Navigation radar. It is installed on the ship, used to observe the islands and coastal targets to determine the ship's position, and guide and supervise the ship's navigation according to the displayed route. ③ Terrain following and terrain avoidance radar. It is installed on the plane to ensure the safety of low-altitude and ultra-low-altitude flight. Combined with relevant airborne equipment, the aircraft can maintain a certain safe altitude during flight and automatically avoid terrain obstacles. (4) Landing (ship) radar. It is used to guide the plane to land or land safely under complex meteorological conditions. Usually erected on the deck of an airport or an aircraft carrier on one side of the middle section of the runway. Meteorological radar used for meteorological observation can detect the state of clouds and rain in the air, determine the height and thickness of clouds, and determine meteorological elements such as wind direction and wind speed in different atmospheres. It includes rain radar, cloud radar and wind radar. In addition, according to the different installation positions of radar, it can be divided into ground radar, airborne radar, shipborne radar, missile-borne radar, space radar, ball-borne radar and so on. According to different working frequency bands, it can be divided into meter wave radar, decimeter wave radar, centimeter wave radar and millimeter wave radar. According to the different forms of transmitted signals, it can be divided into pulse radar, continuous wave radar and pulse compression radar. According to the different control methods of antenna beam scanning, it can be divided into mechanical scanning radar, electromechanical scanning radar, frequency scanning radar and phased array radar. Development trend: the working frequency band of radar will continue to expand to both ends of electromagnetic spectrum; The application of microelectronics and solid-state technology will realize the miniaturization of radar; Using computer to manage and control radar will realize the automation of operation, calibration, performance and fault detection, and develop adaptive anti-jamming technology; In small and medium-sized ground, ship-borne and airborne radars, phased array technology will be widely used to realize the multi-function of radar; It will improve the radar's ability to identify the actual image, size, motion posture and bait of the target, and enhance the radar's ability to resist nuclear attacks and anti-radiation missile damage; New radar systems will be developed, such as multi-base radar, passive radar, spread spectrum radar and noise radar. [8] Gun aiming radar is used to automatically track air targets, determine target coordinates, and control anti-aircraft gun aiming shooting through the director. Also known as artillery control radar. It is an integral part of anti-aircraft gun system. [9] Battlefield reconnaissance radar A radar that detects moving targets on the ground. It is mainly equipped in army units, and is used to alert and detect targets such as people, cars and tanks in enemy movement, determine their orientation, distance and activity route, and provide information on enemy ground activities. According to the different range of radar, battlefield reconnaissance radar can be divided into short-range (about 10 km) portable and long-range (about 20 ~ 40 km) vehicle-mounted radar. According to the different radar emission waveforms, it can be divided into two systems: continuous wave and pulse wave. This kind of radar generally uses a wavelength of 3 cm or less to improve accuracy and reduce volume and weight. Because the environment around the target is often accompanied by many ground objects, this kind of radar usually adopts moving target detection technology in order to detect the target signal from the strong ground clutter. . [1 1] The field of view of the side-looking radar is perpendicular to the direction of the aircraft, and it is used to detect the synthetic aperture radars on both sides of the aircraft. Side-looking radar on aircraft includes transmitter, receiver, sensor, data storage and processing equipment, etc. In the early days, real aperture radar was used to detect targets, and the resolution of radar images was improved by directly increasing the antenna aperture and emitting narrow pulses.