laser radar
Radar that uses a laser as a source of radiation. Lidar is the product of the combination of laser technology and radar technology . By the transmitter, antenna, receiver, tracking frame and information processing and other components. The transmitter is a variety of forms of lasers, such as carbon dioxide lasers, neodymium-doped yttrium aluminum garnet lasers, semiconductor lasers and wavelength tunable solid-state lasers, etc.; antenna is an optical telescope; the receiver uses a variety of forms of photodetectors, such as photomultiplier tubes, semiconductor photodiodes, avalanche photodiodes, infrared and visible multi-detector devices, etc.. Lidar uses pulse or continuous wave 2 kinds of work, detection method is divided into direct detection and differential detection.
Lidar in the military can be used for a variety of flight target trajectory measurement. Such as the initial section of the missile and rocket tracking and measurement, low elevation angle tracking measurement of aircraft and cruise missiles, satellite precision orbiting. LIDAR combined with infrared, television and other optoelectronic equipment, composed of ground, shipboard and airborne fire control system, the target for search, identification, tracking and measurement. As LIDAR can obtain three-dimensional images of the target and speed information, it is beneficial to identify stealthy targets. LIDAR can monitor the atmosphere, remotely detect pollution and toxic agents in the atmosphere, and also measure the temperature, humidity, wind speed, visibility and cloud height of the atmosphere.
Laser radar applications
●Meng Min Wang Xuecai
Laser radar, developed using a principle and construction similar to that of a laser rangefinder, is a detection system that operates in the infrared to ultraviolet spectral band. Usually, the use of laser pulses for detection is called pulsed LIDAR, and the use of continuous wave laser beams for detection is called continuous wave LIDAR. At present, the world has developed for fire control, reconnaissance, guidance, measurement, navigation and other functions of the laser radar.
Biochemical warfare masters: land-based LIDAR
Biochemical warfare agent detection and prevention, has been one of the military's focus on key projects. Traditional detection methods, mainly by soldiers carrying detection devices, walking while measuring, slow, low efficacy, and easy poisoning. Reportedly, Russia changed the traditional way, successfully developed a "KDKhr-1N" long-distance ground agent LIDAR detection system, real-time long-distance detection and determination of toxic agent aerosol cloud slanting distance, the center of the thickness of the height from the ground, the center of the angular coordinates as well as toxic agent-related parameters, etc., in a timely manner, through the wireless technology to the control system of the army. Through there, wireless technology to the force control system alarm, in order to take appropriate anti-drug measures. In this regard, the German military has also developed a more advanced "VTB --- 1 type" telemetry LIDAR, using two 9 micron - 11 micron, can be adjusted on 40 frequency of continuous-wave C02 lasers to telemetry chemical warfare agents using differential absorption spectroscopy, which is both safe and reliable.
Flight collision master: air with LiDAR
Aircraft, especially helicopters in low-altitude patrol flight, very easy to collide with the ground hill or building, which is a lot of countries around the world and seek to solve a major problem. The United States, Germany and France have taken great pains in recent years to develop a helicopter obstacle avoidance LIDAR, successfully solved this problem. The United States took the lead in the development of helicopter ultra-low altitude flight "obstacle avoidance radar", the use of solid-state laser diode transmitter and rotating holographic scanner, can detect the helicopter in front of a very wide airspace, the ground obstacle information can be displayed in real time in the on-board flat-screen display or helmet display, to protect the pilot's safety flight. With the successful development of Germany's "Hellas" LIDAR is better, it is a solid 1.54 micron imaging, field of view of 32 degrees × 32 degrees, can detect 300 meters -500 meters distance within the diameter of 1 cm thick wires or obstacles, helicopters can ensure flight safety by using it! Safety. France and the United Kingdom jointly developed a pod-carrying "CLARA" LIDAR, with a variety of functions, the use of C02 lasers, not only can measure the helicopter flying ahead such as poles, cables and other micro-obstacles, but also for terrain tracking, target ranging and active target instructions to ensure flight safety, this LIDAR is also suitable for use in the aircraft.
Capture underwater target masters: the sea with LIDAR
The traditional way of alerting, searching, characterization and tracking of targets in the water, is to use the body is large and heavy, generally in the 600 kg to dozens of tons of sonar. Since the development of marine LiDAR, that is, airborne blue-green laser transmitter and receiver equipment, marine underwater target detection is simple and convenient, but also accurate. Especially in the 1990s after the successful development of the third generation of LiDAR, increased GPS positioning, fixed height function, the realization of the course and height of the automatic control. Such as the United States Northrop developed "ALARMS" airborne mine detection lidar, can work 24 hours, can accurately measure the underwater mines and other suspicious targets. Underwater imaging lidar developed by the U.S. Kaman Aerospace Corporation, more advantageous, can show the shape of underwater targets and other characteristics, accurate capture of the target in order to take emergency measures to ensure navigation safety.
In addition, LIDAR can also be widely used in countering electronic warfare, anti-radiation missiles, ultra-low-altitude surprise defense, missile and artillery guidance and land mine clearance.