Modern wars are distinguished by their swiftness and transience. Often the winners in military clashes are those who were the first to detect potential threats and react to them accordingly. For eight decades now, radar methods have been used for reconnaissance and recognition of the enemy at sea and on land, as well as in the air.
They are based on the emission of radio waves with the recording of their reflections from a wide variety of objects. Installations that send and receive such signals are modern radar stations or radars. The concept of “radar” comes from the English abbreviation – RADAR. It appeared in 1941 and has long been included in the languages of the world.
The advent of radar was a landmark event. In the modern world, it is practically impossible to do without radar stations. Aviation, navigation, hydrometeorological center, traffic police, etc. cannot do without them. Moreover, the radar complex is widely used in space technologies and in navigation systems.
Radar in military service
Still, the military liked radars most of all. Moreover, these technologies were originally created for military use and were practically implemented before the Second World War. All major states actively used radar to detect enemy ships and aircraft. Moreover, their use decided the outcome of many battles.
Today, new radar stations are used in a very wide range of military tasks. This includes tracking intercontinental ballistic missiles and artillery reconnaissance. All planes, helicopters, and warships have their own radar. Radars are generally the basis of air defense systems.
How do radars work?
Location is the definition of where something is. Thus, radar is the detection of objects or objects in space using radio waves that are emitted and received by a radar or radar. The principle of operation of primary or passive radars is based on the transmission into space of radio waves reflected from objects and returned to them in the form of reflected signals. After their analysis, radars detect objects at certain points in space, their main characteristics in the form of speed, height and size. All radars are complex radio engineering devices made up of many elements.
Modern radar complex
Any radar consists of three main elements:
- Signal transmitters;
- Antenna;
- Receivers.
Of all radar stations, there is a special division into two large groups:
- Pulse;
- Continuous action.
Pulse radar transmitters emit electromagnetic waves for short periods of time (fractions of seconds). The next signals are sent only when the first pulses return and hit the receivers. Pulse repetition rates are also important characteristics. So low-frequency radars send more than one hundred pulses within a minute.
Pulse radar antennas work as receivers and transmitters. As soon as the signals are gone, the transmitters turn off for a while and the receivers turn on. Following their reception, reverse processes occur.
Pulse radars have their disadvantages and advantages. They can determine the range of several targets simultaneously. Such radars may have one antenna each, and their indicators are very simple.
However, the emitted signals must have high power. All modern tracking radars have a pulse circuit. Pulse radar stations usually use magnetrons or traveling wave tubes as signal sources.
Pulse radar systems
Radar antennas focus and direct electromagnetic signals, and also pick up reflected pulses and transmit them to receivers. In some radars, signals can be received and transmitted using different antennas located at large distances from one another. Radar antennas can emit electromagnetic waves in a circle or operate in certain sectors.
Radar beams can be directed spirally or have the shape of cones. If necessary, radars can track moving targets and point antennas at them all the time using special systems. Receivers process the received data and transmit it to the operators’ screens.
One of the main disadvantages in the operation of pulse radars is interference coming from real objects, from the earth's surface, mountains, and hills. Thus, on-board pulse radars during their operation in aircraft will receive shadows from signals reflected by the earth's surface. Ground-based or shipborne radar systems detect these problems by detecting targets that fly at low altitudes. To eliminate such interference, the Doppler effect is used.
Continuous Range Radars
Continuous-wave radars operate by continuously emitting electromagnetic waves and use the Doppler effect. Its principle is that the frequencies of electromagnetic waves reflected from objects approaching signal sources will be higher than from objects moving away. In this case, the frequencies of the emitted pulses remain unchanged. Such radars do not detect stationary objects; their receivers only detect waves with frequencies higher or lower than those emitted.
The main disadvantage of continuous-wave radars is their inability to determine distances to objects. However, their operation does not cause interference from stationary objects between or behind the radars and targets. Also, Doppler radars have a relatively simple device that can operate using low-power signals. In addition, modern continuous-wave radar stations have the ability to determine distances to objects. To do this, changes in radar frequencies are used during their operation.
We also know about the so-called secondary radars used in aviation to identify aircraft. Such radar systems also have aircraft transponders. During the irradiation of aircraft with electromagnetic signals, the transponders provide additional data, such as altitude, route, aircraft number, and nationality.
Types of radar stations
Radars can be separated by the length and frequency of the waves on which they operate. In particular, when examining the earth's surface and when working at long distances, waves of 0.9-6 m and 0.3-1 m are used. In air traffic control, radars with a wavelength of 7.5-15 cm are used, and in over-the-horizon radars At stations for detecting missile launches, 10-100-meter waves are used.
From the history of radar development
The idea of using radar arose after the discovery of radio waves. So, in 1905, Siemens employee Christian Hülsmeyer created a device that could detect the presence of large metal objects using radio waves. The inventor proposed installing such devices on ships to avoid collisions, for example, in fog. However, shipping companies have not expressed interest in the new device.
Radar studies were also carried out on Russian territory. Thus, back at the end of the 19th century, the Russian scientist Popov discovered that the presence of metal objects prevents the propagation of radio waves.
In the early twenties, American engineers Albert Taylor and Leo Young discovered a passing ship using radio waves. However, due to the fact that the radio engineering industry of that time was undeveloped, it was not possible to create radar stations on an industrial scale.
The production of the first radar stations, with the help of which practical problems could be solved, began in England in the 30s. This equipment was extremely bulky and could be installed either on the ground or on large ships. It was only in 1937 that the first miniature radar was created that could be installed on airplanes. As a result, before World War II, the British had an extensive network of radar stations called Chain Home.
Cold War radars
During the Cold War, a new type of destructive weapon emerged in the United States and the Soviet Union. Of course, this was the advent of intercontinental ballistic missiles. Timely detection of launches of such missiles was vital.
Soviet scientist Nikolai Kabanov proposed the idea of using short radio waves to detect enemy aircraft at significant distances (up to 3000 km). Everything was quite simple. The scientist was able to discover that 10-100-meter radio waves tend to be reflected from the ionosphere.
Thus, when targets on the earth's surface are irradiated, they also return back to the radars. Later, based on this idea, scientists were able to develop radars with over-the-horizon detection of ballistic missile launches. An example of such installations can be “Daryal” - a radar station. For decades it was at the heart of Soviet systems for preventing missile launches.
Today, the most promising direction in the development of radar systems is considered to be the creation of radar stations with phased array antennas (PAA). Such devices have not one, but hundreds of radio wave emitters. All their functioning is controlled by powerful computers. Radio waves emitted from different sources in a phased array can amplify one another, or vice versa, when they are in phase or attenuated.
Phased array radar signals can be given any desired shape. They can move in space without changes in the positions of the antennas themselves, and also operate at different radiation frequencies. Phased array radars are considered more reliable and sensitive than similar devices with conventional antennas.
However, such radars also have disadvantages. The biggest problems with phased array radars are their cooling systems. Moreover, such radar installations are extremely complex to manufacture and are also very expensive.
Radar complexes with phased arrays
What is known about new phased array radars is that they are already being installed on fifth-generation fighters. Such technologies are used in American early warning systems for missile attacks. Radar systems with phased arrays are supposed to be installed on the Armata, the latest Russian-made tanks. Many experts note that the Russian Federation is among the world leaders that are successfully developing radar stations with phased arrays.
Good evening everyone :) I was surfing the Internet after visiting a military unit with a considerable number of radar stations.
I was very interested in the radars themselves. I think it’s not just me, so I decided to post this article :)
Radar stations P-15 and P-19
The P-15 UHF radar is designed to detect low-flying targets. Entered service in 1955. It is used as part of radar posts of radio engineering formations, control batteries of anti-aircraft artillery and missile formations of the operational air defense level and at tactical level air defense control posts.
The P-15 station is mounted on one vehicle along with the antenna system and is deployed into a combat position in 10 minutes. The power supply unit is transported in a trailer.
The station has three operating modes:
- amplitude;
- amplitude with accumulation;
- coherent-pulse. 
The P-19 radar is designed to conduct reconnaissance of air targets at low and medium altitudes, detect targets, determine their current coordinates in azimuth and identification range, as well as transmit Radar information to command posts and associated systems. It is a mobile two-coordinate radar station located on two vehicles.
The first vehicle houses transmitting and receiving equipment, anti-jamming equipment, indicator equipment, equipment for transmitting radar information, simulating, communicating and interfacing with consumers of radar information, functional control and ground-based radar interrogator equipment.
The second vehicle houses the radar antenna-rotator device and power supply units.
Difficult climatic conditions and the duration of operation of the P-15 and P-19 radar stations have led to the fact that by now most of the radars require resource restoration.
The only way out of this situation is considered to be the modernization of the old radar fleet based on the Kasta-2E1 radar.
The modernization proposals took into account the following:
Maintaining the integrity of the main radar systems (antenna system, antenna rotation drive, microwave path, power supply system, vehicles);
Possibility of modernization under operating conditions with minimal financial costs;
Possibility of using released P-19 radar equipment to restore products that have not been upgraded.
As a result of modernization, the P-19 mobile solid-state low-altitude radar will be capable of performing airspace control tasks, determining the range and azimuth of airborne objects - airplanes, helicopters, remotely piloted aircraft and cruise missiles, including those operating at low and extremely low altitudes, at against a background of intense reflections from the underlying surface, local objects and hydrometeorological formations.
The radar is easily adaptable for use in various military and civil systems. It can be used for information support of air defense systems, air forces, coastal defense systems, rapid reaction forces, and traffic control systems for civil aviation aircraft. In addition to traditional use as a means of detecting low-flying targets in the interests of the armed forces, the modernized radar can be used to control airspace in order to suppress the transportation of weapons and drugs by low-altitude, low-speed and small-sized aircraft in the interests of special services and police units involved in the fight against drug trafficking and weapons smuggling .
Upgraded radar station P-18
Designed to detect aircraft, determine their current coordinates and issue target designations. It is one of the most popular and cheapest meter stations. The service life of these stations has been largely exhausted, and their replacement and repair are difficult due to the lack of currently outdated components.
To extend the service life of the P-18 radar and improve a number of tactical and technical characteristics, the station was modernized based on an installation kit that has a resource of at least 20-25 thousand hours and a service life of 12 years.
Four additional antennas were introduced into the antenna system for adaptive suppression of active interference, installed on two separate masts. The purpose of the modernization is to create a radar with performance characteristics that meet modern requirements, while maintaining the appearance of the base product due to:
- replacement of the outdated element base of the P-18 radar equipment with a modern one;
- replacement of a tube transmitting device with a solid state one;
- introduction of a signal processing system on digital processors;
- introduction of an adaptive suppression system for active noise interference;
- introduction of systems for secondary processing, monitoring and diagnostics of equipment, information display and control based on a universal computer;
- ensuring interface with modern automated control systems.
As a result of modernization:
- the volume of equipment has been reduced;
- increased reliability of the product;
- increased noise immunity;
- improved accuracy characteristics;
- improved performance characteristics.
The installation kit is built into the radar control cabin instead of the old equipment. The small dimensions of the installation kit allow upgrading of products on site.
Radar complex P-40A
Range finder 1RL128 “Armor”
The 1RL128 Bronya radar rangefinder is an all-round radar and, together with the 1RL132 radar altimeter, forms the P-40A three-dimensional radar complex.
Rangefinder 1RL128 is intended for:
- detection of air targets;
- determination of slant range and azimuth of air targets;
- automatic output of the altimeter antenna to the target and display of the target height value according to the altimeter data;
- determination of state ownership of targets (“friend or foe”);
- control your aircraft using the all-round visibility indicator and the R-862 aircraft radio;
- direction finding of active jammers.
The radar complex is part of radio engineering formations and air defense formations, as well as anti-aircraft missile (artillery) units and military air defense formations.
Structurally, the antenna-feeder system, all equipment and ground-based radar interrogator are placed on a 426U self-propelled tracked chassis with its components. In addition, it houses two gas turbine power units.
Two-dimensional standby radar "Sky-SV"
Designed for detection and identification of air targets in standby mode when operating as part of military air defense radar units, equipped and not equipped with automation equipment.
The radar is a mobile coherent pulse radar station located on four transport units (three cars and a trailer).
The first vehicle contains transmitting and receiving equipment, anti-interference equipment, indicator equipment, equipment for auto-recording and transmission of radar information, simulation, communication and documentation, interface with consumers of radar information, functional monitoring and continuous diagnostics, equipment for a ground-based radar interrogator (GRI).
The second vehicle is equipped with a radar rotating antenna device.
The third car has a diesel power plant.
An NRZ antenna-rotating device is placed on the trailer.
The radar can be equipped with two remote all-round indicators and interface cables.
Mobile three-coordinate radar station 9S18M1 “Dome”
Designed to provide radar information to command posts of anti-aircraft missile formations and military air defense units and control posts of air defense system facilities of motorized rifle and tank divisions equipped with the Buk-M1-2 and Tor-M1 air defense systems.
The 9S18M1 radar is a three-coordinate coherent-pulse detection and target designation station that uses long-duration probing pulses, which provides high energy emitted signals.
The radar is equipped with digital equipment for automatic and semi-automatic coordinate acquisition and equipment for identifying detected targets. The entire process of radar operation is as automated as possible thanks to the use of high-speed computing electronic means. To increase the efficiency of operation in conditions of active and passive interference, the radar uses modern methods and means of noise protection.
The 9S18M1 radar is located on a cross-country tracked chassis and is equipped with an autonomous power supply system, navigation, orientation and topographical equipment, telecode and voice radio communications. In addition, the radar has a built-in automated functional control system, which ensures quick detection of a faulty replacement element and a simulator for processing operator skills. To transfer them from the traveling position to the combat position and back, devices for automatic deployment and collapse of the station are used.
The radar can operate in harsh climatic conditions, move under its own power on roads and off-road, and can also be transported by any type of transport, including air.
Air Force Air Defense
Radar station "Oborona-14"
Designed for long-range detection and measurement of range and azimuth of air targets when operating as part of an automated control system or autonomously.
The radar is located on six transport units (two semi-trailers with equipment, two with an antenna-mast device and two trailers with a power supply system). A separate semi-trailer has a remote post with two indicators. It can be removed from the station at a distance of up to 1 km. To identify air targets, the radar is equipped with a ground-based radio interrogator.
The station uses a folding antenna system design, which significantly reduces its deployment time. Protection against active noise interference is provided by tuning the operating frequency and a three-channel auto-compensation system, which allows you to automatically form “zeros” in the antenna radiation pattern in the direction of the jammers. To protect against passive interference, coherent-compensation equipment on potential-scopic tubes is used.
The station provides three modes of viewing the space:
- “lower beam” - with an increased target detection range at low and medium altitudes;
- “upper beam” - with an increased upper limit of the detection zone in elevation;
Scans - with alternate (through review) inclusion of the upper and lower beams.
The station can be operated at an ambient temperature of ± 50 °C, wind speed up to 30 m/s. Many of these stations were exported and are still in use by the troops.
The Oborona-14 radar can be upgraded using a modern element base using solid-state transmitters and a digital information processing system. The developed installation kit of the equipment allows us to carry out work on modernizing the radar directly at the consumer's site in a short time, bringing its characteristics closer to the characteristics of modern radars, and extending the service life by 12 - 15 years at a cost several times lower than when purchasing a new station.
Radar station "Sky"
Designed to detect, identify, measure three coordinates and track air targets, including aircraft manufactured using stealth technology. It is used in air defense forces as part of an automated control system or independently.
The all-round radar "Sky" is located on eight transport units (on three semi-trailers - an antenna-mast device, on two - equipment, on three trailers - an autonomous power supply system). There is a remote device transported in containers.
The radar operates in the meter wavelength range and combines the functions of a range finder and altimeter. In this range of radio waves, the radar is slightly vulnerable to homing projectiles and anti-location missiles operating in other ranges, and in the operating range these weapons are currently absent. In the vertical plane, electronic scanning with an altimeter beam is implemented (without the use of phase shifters) in each range resolution element.
Noise immunity under conditions of active interference is ensured by adaptive adjustment of the operating frequency and a multi-channel auto-compensation system. The passive interference protection system is also built on the basis of correlation auto-compensators.
For the first time, to ensure noise immunity under conditions of exposure to combined interference, spatio-temporal decoupling of protection systems against active and passive interference has been implemented.
Measuring and issuing coordinates is carried out using auto-recording equipment based on a built-in special computer. There is an automated monitoring and diagnostic system.
The transmitting device is highly reliable, which is achieved through 100% redundancy of a powerful amplifier and the use of a group solid-state modulator.
The Nebo radar can be operated at ambient temperatures of ± 50 °C and wind speeds of up to 35 m/s.
Three-dimensional mobile surveillance radar 1L117M
Designed to monitor airspace and determine three coordinates (azimuth, slant range, altitude) of air targets. The radar is built on modern components, has high potential and low energy consumption. In addition, the radar has a built-in state identification interrogator and equipment for primary and secondary data processing, a set of remote indicator equipment, thanks to which it can be used in automated and non-automated air defense systems and the Air Force for flight control and interception guidance, as well as for air control traffic (ATC).
Radar 1L117M is an improved modification of the previous model 1L117.
The main difference of the improved radar is the use of a klystron output power amplifier of the transmitter, which made it possible to increase the stability of the emitted signals and, accordingly, the passive interference suppression coefficient and improve performance against low-flying targets.
In addition, due to the presence of frequency tuning, the performance of the radar in interference conditions has been improved. The radar data processing device uses new types of signal processors, and the remote control, monitoring and diagnostic system is improved.
The main set of 1L117M radar includes:
Machine No. 1 (transceiver) consists of: lower and upper antenna systems, a four-channel waveguide path with PRL transmitting and receiving equipment and state identification equipment;
Machine No. 2 has a collection cabinet (point) and an information processing cabinet, a radar indicator with remote control;
Vehicle No. 3 carries two diesel power plants (main and backup) and a set of radar cables;
Machines No. 4 and No. 5 contain auxiliary equipment (spare parts, cables, connectors, installation kit, etc.). They are also used for transporting disassembled antenna systems.
The overview of the space is ensured by the mechanical rotation of the antenna system, which forms a V-shaped radiation pattern consisting of two beams, one of which is located in a vertical plane, and the other in a plane located at an angle of 45 to the vertical. Each radiation pattern in turn is formed by two beams formed at different carrier frequencies and having orthogonal polarization. The radar transmitter generates two consecutive phase-code-manipulated pulses at different frequencies, which are sent to the feeds of the vertical and inclined antennas through the waveguide path.
The radar can operate in low pulse repetition rate mode, providing a range of 350 km, and in frequent sending mode with a maximum range of 150 km. At higher rotation speeds (12 rpm), only the frequent mode is used.
The receiving system and digital equipment of the SDC ensure the reception and processing of target echo signals against the background of natural interference and meteorological formations. The radar processes echoes in a "moving window" with a fixed false alarm rate and has inter-view processing to improve target detection against background noise.
The SDC equipment has four independent channels (one for each receiving channel), each of which consists of a coherent and amplitude part.
The output signals of the four channels are combined in pairs, as a result of which normalized amplitude and coherent signals of the vertical and oblique beams are supplied to the radar extractor.
The information acquisition and processing cabinet receives data from the PLR and state identification equipment, as well as rotation and synchronization signals, and provides: selection of an amplitude or coherent channel in accordance with the interference map information; secondary processing of radar images with the construction of trajectories based on radar data, combining radar markers and state identification equipment, displaying the air situation on the screen with forms “linked” to targets; extrapolation of target location and collision prediction; introduction and display of graphic information; identification mode control; solving guidance (interception) problems; analysis and display of meteorological data; statistical assessment of radar operation; generation and transmission of exchange messages to control points.
The remote monitoring and control system ensures automatic operation of the radar, control of operating modes, performs automatic functional and diagnostic monitoring of the technical condition of equipment, identification and troubleshooting with display of methods for carrying out repair and maintenance work.
The remote monitoring system ensures localization of up to 80% of faults with an accuracy of a typical replacement element (REE), in other cases - up to a group of TEZ. The display screen of the workplace provides a complete display of characteristic indicators of the technical condition of radar equipment in the form of graphs, diagrams, functional diagrams and explanatory notes.
It is possible to transmit radar data via cable communication lines to remote display equipment for air traffic control and providing guidance and interception control systems. The radar is supplied with electricity from the included autonomous power supply; can also be connected to an industrial network 220/380 V, 50 Hz.
Radar station "Casta-2E1"
Designed to control airspace, determine the range and azimuth of air objects - airplanes, helicopters, remotely piloted aircraft and cruise missiles flying at low and extremely low altitudes, against the backdrop of intense reflections from the underlying surface, local objects and hydrometeorological formations.
The Kasta-2E1 mobile solid-state radar can be used in various systems for military and civil purposes - air defense, coastal defense and border control, air traffic control and airspace control in airfield areas.
Distinctive features of the station:
- block-modular construction;
- interfacing with various information consumers and issuing data in analog mode;
- automatic control and diagnostic system;
- additional antenna-mast kit for installing the antenna on a mast with a lifting height of up to 50 m
- solid-state radar construction
- high quality of output information when exposed to pulsed and noise active interference;
- the ability to protect and interface with means of protection against anti-radar missiles;
- the ability to determine the nationality of detected targets.
The radar includes a hardware machine, an antenna machine, an electrical unit on a trailer and a remote operator’s workstation, which allows you to control the radar from a protected position at a distance of 300 m.
The radar antenna is a system consisting of two mirror antennas with feeds and compensation antennas located on two floors. Each antenna mirror is made of metal mesh, has an oval contour (5.5 m x 2.0 m) and consists of five sections. This makes it possible to stack the mirrors during transportation. When using a standard support, the position of the phase center of the antenna system is ensured at a height of 7.0 m. Review in the elevation plane is carried out by forming one beam of a special shape, in azimuth - due to uniform circular rotation at a speed of 6 or 12 rpm.
To generate sounding signals in the radar, a solid-state transmitter is used, made on microwave transistors, which makes it possible to obtain a signal with a power of about 1 kW at its output.
Receiving devices carry out analog processing of signals from three main and auxiliary receiving channels. To amplify the received signals, a solid-state low-noise microwave amplifier is used with a transmission coefficient of at least 25 dB with an intrinsic noise level of no more than 2 dB.
The radar modes are controlled from the operator's workstation (OW). Radar information is displayed on a coordinate-sign indicator with a screen diameter of 35 cm, and the results of monitoring radar parameters are displayed on a table-sign indicator.
The Kasta-2E1 radar remains operational in the temperature range from -50 °C to +50 °C in conditions of precipitation (frost, dew, fog, rain, snow, ice), wind loads up to 25 m/s and the location of the radar on altitude up to 2000 m above sea level. The radar can operate continuously for 20 days.
To ensure high availability of the radar, there is redundant equipment. In addition, the radar kit includes spare equipment and accessories (SPTA) designed for a year of operation of the radar.
To ensure the readiness of the radar throughout its entire service life, group spare parts and accessories are supplied separately (1 set for 3 radars).
The average service life of the radar before major repairs is 1 15 thousand hours; The average service life before major repairs is 25 years.
The Kasta-2E1 radar has a high modernization capability in terms of improving individual tactical and technical characteristics (increasing potential, reducing the volume of processing equipment, display equipment, increasing productivity, reducing deployment and deployment time, increasing reliability, etc.). It is possible to supply the radar in a container version using a color display.
Radar station "Casta-2E2"
Designed to control airspace, determine range, azimuth, flight altitude and route characteristics of air objects - airplanes, helicopters, remotely piloted aircraft and cruise missiles, including those flying at low and extremely low altitudes, against the background of intense reflections from the underlying surface , local objects and hydro-meteorological formations. The low-altitude three-dimensional all-round radar of the standby mode "Casta-2E2" is used in air defense systems, coastal defense and border control, air traffic control and airspace control in airfield areas. Easily adapts to use in various civil systems.
Distinctive features of the station:
- block-modular construction of most systems;
- deployment and collapse of a standard antenna system using automated electromechanical devices;
- completely digital processing of information and the ability to transmit it via telephone channels and radio channels;
- completely solid-state construction of the transmission system;
- the possibility of installing the antenna on a light high-altitude support of the Unzha type, which ensures that the phase center is raised to a height of up to 50 m;
- the ability to detect small objects against the background of intense interfering reflections, as well as hovering helicopters while simultaneously detecting moving objects;
- high protection from asynchronous impulse interference when working in dense groups of radio-electronic equipment;
- a distributed complex of computing tools that provides automation of the processes of detection, tracking, measurement of coordinates and identification of the nationality of air objects;
- the ability to issue radar information to the consumer in any form convenient for him - analog, digital-analog, digital coordinate or digital trace;
- the presence of a built-in functional diagnostic monitoring system, covering up to 96% of the equipment.
The radar includes hardware and antenna vehicles, main and backup power plants, mounted on three KamAZ-4310 off-road vehicles. It has a remote operator workstation that provides control of the radar, located at a distance of 300 m from it.
The design of the station is resistant to the effects of excess pressure in the shock wave front, and is equipped with sanitary and individual ventilation devices. The ventilation system is designed to operate in recirculation mode without using intake air.
The radar antenna is a system consisting of a double-curvature mirror, a horn feed assembly, and side-lobe suppression antennas. The antenna system forms two beams with horizontal polarization along the main radar channel: sharp and cosecant, covering a given viewing sector.
The radar uses a solid-state transmitter made of microwave transistors, which makes it possible to receive a signal with a power of about 1 kW at its output.
The radar modes can be controlled either by operator commands or by using the capabilities of a complex of computing tools.
The radar ensures stable operation at ambient temperatures of ±50 °C, relative air humidity up to 98%, and wind speeds up to 25 m/s. The altitude above sea level is up to 3000 m. Modern technical solutions and element base used in the creation of the Kasta-2E2 radar made it possible to obtain tactical and technical characteristics at the level of the best foreign and domestic models.
Thank you all for your attention :)
In our country, almost 15 thousand drugs and several thousand more biologically active food additives are officially registered and approved for medical use. If we count them with dosage forms, then there will be several tens of thousands. So it doesn't cost anything to get confused. So that you can always find the answer to your query, the creators of the radar system have placed all available information in a database, which serves as the basis for all reference books of the radar system. We will talk about each of them in more detail below. And now the main thing is to understand that comprehensive information can only be obtained if you use the whole system , and not as a separate part of it.
What does a radar system consist of?
The book you are holding in your hands, RLS-PATIENT, is part of the unique system of Russian radar reference books. This drug information system includes four annual printed publications with a total circulation of approximately 300,000 copies and three electronic reference books (Figure 2.2.2).
THE ENCYCLOPEDIA OF MEDICINES (top left in Figure 2.2.2) contains the latest information about domestic and foreign drugs (including substances, biologically active food additives, homeopathic and diagnostic products) declared by manufacturers for supply. The book was prepared by the country's leading pharmacologists and is intended for doctors, pharmacists and other specialists in the field of drug supply. An annual publication equipped with subject, pharmacological, nosological indexes based on the International Classification of Diseases, Tenth Revision (ICD-10), an index of anatomical-therapeutic-chemical classification, a color identifier of drugs, an index of drug manufacturers or their representative offices in Russia with office addresses and a list of products products.
RLS-APTOKAR (second book from the top from the left in Figure 2.2.2) includes everything that is registered in Russia. Contains information about all medicines and biologically active food additives registered in Russia, as well as about many medical products, sanitary and hygienic products, patient care products and many other products that you can find in pharmacies. And this is no less than 50,000 titles. Combines all official information from the State Register of Medicines, the Federal Register of Biologically Active Food Additives, and the Federal Register of Hygienic Conclusions. Annual publication. Complete information for the pharmacist - all existing forms of release, storage conditions, expiration dates, dispensing conditions, membership in various lists and much more. Easy search for synonyms and analogues by active ingredients and Pharmacological Index.
RLS-DOCTOR (top right in Figure 2.2.2) will provide invaluable assistance to medical practitioners when prescribing medications. Annual publication. The most commonly used medications and their detailed descriptions. Nosological index based on ICD-10. Addresses, telephone numbers of manufacturers.
RLS-PATIENT is a book about the mechanisms of action of drugs and ensuring good health. It will help the doctor improve the efficiency of communication with the patient and, as a result, make treatment more productive. This book is in your hands and you can appreciate it.
Computer version of RLS-CD: ENCYCLOPEDIA OF MEDICINES - the entire accumulated radar database for real professionals who want to learn the news before anyone else and value their time. Quarterly updates, modern friendly interface, various search options, including contextual.
RLS-CD: NOMENCLATURE OF MEDICINES - a complete list of pharmaceutical products registered in Russia. Includes a combination of 21 features that describe the commercial packaging of a product. A common language for communication in the pharmaceutical market, allowing you to implement the radar database into your information environment and ensure communication with other systems that use the radar nomenclature.
Radar station(radar) or radar(English) radar from Radio Detection and Ranging- radio detection and ranging) - a system for detecting air, sea and ground objects, as well as for determining their range and geometric parameters. Uses a method based on the emission of radio waves and recording their reflections from objects. The English acronym term appeared in the city; subsequently, in its writing, capital letters were replaced by lowercase ones.
Story
On January 3, 1934, an experiment was successfully carried out in the USSR to detect an aircraft using the radar method. An aircraft flying at an altitude of 150 meters was detected at a distance of 600 meters from the radar installation. The experiment was organized by representatives of the Leningrad Institute of Electrical Engineering and the Central Radio Laboratory. In 1934, Marshal Tukhachevsky wrote in a letter to the USSR government: “Experiments in detecting aircraft using an electromagnetic beam confirmed the correctness of the underlying principle.” The first experimental installation "Rapid" was tested in the same year; in 1936, the Soviet centimeter radar station "Storm" detected the aircraft from a distance of 10 kilometers. In the United States, the first military contract with industry was concluded in 1939. In 1946, American experts Raymond and Hacherton, a former employee of the US Embassy in Moscow, wrote: “Soviet scientists successfully developed the theory of radar several years before radar was invented in England.”
Radar classification
By purpose, radar stations can be classified as follows:
- detection radar;
- Control and tracking radar;
- Panoramic radars;
- Side-view radar;
- Meteorological radars.
Depending on the scope of application, military and civilian radars are distinguished.
By the nature of the carrier:
- Ground radars
- Naval radars
- Airborne radars
By type of action
- Primary or passive
- Secondary or active
- Combined
By wave range:
- Meter
- Centimeter
- Millimeter
Design and principle of operation of the Primary Radar
Primary (passive) radar mainly serves to detect targets by illuminating them with an electromagnetic wave and then receiving the reflections (echoes) of this wave from the target. Since the speed of electromagnetic waves is constant (the speed of light), it becomes possible to determine the distance to the target based on measuring the propagation time of the signal.
A radar station is based on three components: transmitter, antenna and receiver.
Transmitting device is a source of high power electromagnetic signal. It can be a powerful pulse generator. For pulsed centimeter range radars, it is usually a magnetron or pulse generator operating according to the following scheme: a master oscillator is a powerful amplifier, most often using a traveling wave lamp as a generator, and for meter range radars, a triode lamp is often used. Depending on the design, the transmitter operates either in pulse mode, generating repeating short powerful electromagnetic pulses, or emits a continuous electromagnetic signal.
Antenna performs focusing of the receiver signal and formation of a radiation pattern, as well as receiving the signal reflected from the target and transmitting this signal to the receiver. Depending on the implementation, the reflected signal can be received either by the same antenna or by another, which can sometimes be located at a considerable distance from the transmitting device. If transmission and reception are combined in one antenna, these two actions are performed alternately, and to prevent the powerful signal leaking from the transmitting transmitter to the receiver from blinding the receiver of a weak echo, a special device is placed in front of the receiver that closes the receiver input at the moment of emission of the probing signal.
Receiver Performs amplification and processing of the received signal. In the simplest case, the resulting signal is fed to a beam tube (screen), which displays an image synchronized with the movement of the antenna.
Coherent radars
The coherent radar method is based on isolating and analyzing the phase difference between the sent and reflected signals, which arises due to the Doppler effect when the signal is reflected from a moving object. In this case, the transmitting device can operate both continuously and in pulse mode. The main advantage of this method is that it “allows you to observe only moving objects, and this eliminates interference from stationary objects located between the receiving equipment and the target or behind it.”
Pulse radars
Operating principle of pulse radar
The principle of determining the distance to an object using pulse radar
Modern tracking radars are built as pulse radars. Pulse radar transmits only for a very short time, the short pulse is usually about a microsecond in duration, after which it listens for an echo while the pulse propagates.
Because the pulse travels away from the radar at a constant speed, the time elapsed from the time the pulse is sent to the time the echo is received is a clear measure of the direct distance to the target. The next pulse can be sent only after some time, namely after the pulse comes back, it depends on the detection range of the radar (given transmitter power, antenna gain and receiver sensitivity). If the pulse were sent earlier, the echo of the previous pulse from a distant target could be confused with the echo of a second pulse from a close target.
The time interval between pulses is called pulse repetition interval, its reciprocal is an important parameter called pulse repetition rate(CPI) . Low-frequency, long-range radars typically have a repetition interval of several hundred pulses per second (or Hertz [Hz]). The pulse repetition rate is one of the distinctive features by which remote determination of the radar model is possible.
Removing Passive Interference
One of the main problems of pulse radars is getting rid of the signal reflected from stationary objects: the earth's surface, high hills, etc. If, for example, an airplane is located against the backdrop of a high hill, the reflected signal from this hill will completely block the signal from the airplane. For ground-based radars, this problem manifests itself when working with low-flying objects. For airborne pulse radars, it is expressed in the fact that reflection from the earth's surface obscures all objects lying below the aircraft with the radar.
Methods for eliminating interference use, one way or another, the Doppler effect (the frequency of a wave reflected from an approaching object increases, and from a departing object it decreases).
The simplest radar that can detect a target in interference is radar with moving target selection(PDS) - a pulse radar that compares reflections from more than two or more pulse repetition intervals. Any target that moves relative to the radar produces a change in the signal parameter (stage in the serial SDC), while the interference remains unchanged. Elimination of interference occurs by subtracting reflections from two consecutive intervals. In practice, noise elimination can be carried out in special devices - through-period compensators or algorithms in software.
CRT operating systems have a fundamental weakness: they are blind to targets with specific circular velocities (which produce phase changes of exactly 360 degrees), and such targets are not imaged. The speed at which a target disappears to the radar depends on the operating frequency of the station and the pulse repetition rate. Modern PRFs emit multiple pulses at different repetition rates - such that the invisible velocities at each pulse repetition rate are captured by other PRFs.
Another way to get rid of interference is implemented in pulse-Doppler radars, which use significantly more complex processing than radars with SDC.
An important property of pulse-Doppler radars is signal coherence. This means that the sent signals and reflections must have a certain phase dependence.
Pulse Doppler radars are generally considered to be superior to SDC radars in detecting low flying targets in multiple ground clutter, this is the preferred technique used in modern fighter aircraft for airborne interception/fire control, examples being the AN/APG-63, 65, 66, 67 and 70 radars. In modern Doppler radar, most of the processing is done digitally by a separate processor using digital signal processors, typically using the high-performance Fast Fourier Transform algorithm to convert the digital data of the reflection patterns into something more manageable by other algorithms. Digital signal processors are very flexible and the algorithms used can usually be quickly replaced by others, replacing only the memory (ROM) chips, thus quickly countering enemy jamming techniques if necessary.
Design and principle of operation of the Secondary Radar
The principle of operation of the secondary radar is somewhat different from the principle of the Primary radar. The Secondary Radar Station is based on the following components: transmitter, antenna, azimuth marker generators, receiver, signal processor, indicator and aircraft transponder with antenna.
Transmitter. Serves to emit request pulses into the antenna at a frequency of 1030 MHz
Antenna. Serves to emit and receive reflected signals. According to ICAO standards for secondary radar, the antenna emits at a frequency of 1030 MHz and receives at a frequency of 1090 MHz.
Azimuth Mark Generators. Serve to generate Azimuth marks (Azimuth Change Pulse or ACP) and generate North Marks (Azimuth Reference Pulse or ARP). For one revolution of the radar antenna, 4096 small azimuth marks (for old systems), or 16384 Small azimuth marks (for new systems), also called improved small azimuth marks (Improved Azimuth Change pulse or IACP), as well as one North mark, are generated. The north mark comes from the azimuth mark generator, with the antenna in such a position when it is directed to the North, and small azimuth marks serve to count the antenna rotation angle.
Receiver. Used to receive pulses at a frequency of 1090 MHz
Signal processor. Serves to process received signals
Indicator Serves to display processed information
Aircraft transponder with antenna Serves to transmit a pulse radio signal containing additional information back to the radar upon receipt of a radio request signal.
Operating principle The principle of operation of the secondary radar is to use the energy of the aircraft transponder to determine the position of the aircraft. The radar irradiates the surrounding space with interrogation pulses at frequencies P1 and P3, as well as a suppression pulse P2 at a frequency of 1030 MHz. Aircraft equipped with transponders located in the range of the interrogation beam upon receiving interrogation pulses, if the condition P1, P3> P2 is in effect, respond to the requesting radar with a series of coded pulses at a frequency of 1090 MHz, which contain additional information such as Board Number, Altitude, and so on. The response of the aircraft transponder depends on the radar request mode, and the request mode is determined by the distance between the request pulses P1 and P3, for example in request mode A (mode A), the distance between the station request pulses P1 and P3 is 8 microseconds, and upon receiving such a request the aircraft transponder encodes its board number in response pulses. In interrogation mode C (mode C), the distance between station interrogation pulses is 21 microseconds and upon receipt of such a request, the aircraft transponder encodes its altitude in the response pulses. The radar can also send a request in a mixed mode, for example Mode A, Mode C, Mode A, Mode C. The azimuth of the aircraft is determined by the angle of rotation of the antenna, which in turn is determined by counting Small Azimuth marks. The range is determined by the delay of the received response. If the Aircraft does not lie in the coverage area of the main beam, but lies in the coverage area of the side lobes, or is located behind the antenna, then the Aircraft transponder, upon receiving a request from the radar, will receive at its input the condition that pulses P1 ,P3 The advantages of a secondary radar are higher accuracy, additional information about the Aircraft (Aircraft number, Altitude), as well as low radiation compared to Primary radars. Wikimedia Foundation. 2010. Radar- Russian Logistics Service http://www.rls.ru/ Radar radar station communications Dictionaries: Dictionary of abbreviations and abbreviations of the army and special services. Comp. A. A. Shchelokov. M.: AST Publishing House LLC, Geleos Publishing House CJSC, 2003. 318 p., With ... Dictionary of abbreviations and abbreviations Radio waves sent into space travel at the speed of light. But as soon as they encounter an object on their way, for example, an airplane or a ship, they are reflected from it and come back. Consequently, with their help it is possible to detect various distant objects, observe them and determine their coordinates and parameters. Detecting the location of objects using radio waves is called radar. Alexander Stepanovich Popov
In 1897, during experimental radio communication sessions between the sea transport "Europe" and the cruiser "Africa", conducted by Russian physicist Alexander Stepanovich Popov, an interesting phenomenon was discovered. It turned out that the correct propagation of the electromagnetic wave was distorted by all metal objects - masts, pipes, gear, both on the ship from which the signal was sent and on the ship where it was received. When the cruiser "Lieutenant Ilyin" appeared between these ships, radio communication between them was broken. This is how the phenomenon of reflection of radio waves from the hull of a ship was discovered. But if radio waves can be reflected from a ship, then ships can be detected with their help. And at the same time other goals. And already in 1904, the German inventor Christian Hülsmeier applied for the first radar, and in 1905 received a patent for using the effect of reflecting radio waves to search for ships. And a year later, in 1906, he proposed using this effect to determine the distance to an object reflecting radio waves. Christian Hülsmeier
In 1934, Scottish physicist Robert Alexander Watson-Watt received a patent for his invention of a system for detecting airborne objects and demonstrated one of the first such devices the following year. Robert Alexander Watson-Watt
Determining the location of something is called location. For this purpose, technology uses a device called locator. The locator emits some type of energy, for example, sound or an optical signal, towards the intended object, and then receives the signal reflected from it. Radar uses radio waves for this purpose. In fact, a radar, or radar station (radar), is a complex system. The designs of different radars may vary, but the principle of their operation is the same. A radio transmitter sends radio waves into space. Having reached the goal, they are reflected from it, like from a mirror, and return back. This type of radar is called active. The main components of a radar are a transmitter, an antenna, an antenna switch, a receiver, and an indicator. Based on the method of emitting radio waves, radars are divided into pulsed and continuous. How does pulse radar work? The radio wave transmitter is turned on for a short time, so the radio waves are emitted in pulses. They enter the antenna, which is located at the focus of a paraboloid-shaped mirror. This is necessary so that radio waves propagate in a certain direction. The operation of a radar is similar to the operation of a light spotlight, the rays of which are similarly directed into the sky and, illuminating it, search for the desired object. But the work of the spotlight is limited to this. And the radar not only sends radio waves, but also receives a signal reflected from the found object (radio echo). This function is performed by the receiver. The pulse radar antenna works either for transmission or reception. There is a switch for this purpose. As soon as the radio signal is sent, the transmitter is turned off and the receiver is turned on. There is a pause, during which the radar seems to “listen” to the broadcast and wait for a radio echo. And as soon as the antenna catches the reflected signal, the receiver immediately turns off and the transmitter turns on. And so on. Moreover, the pause time can be many times longer than the pulse duration. Thus, the emitted and received signals are separated in time. The received radio signal is amplified and processed. The indicator, which in the simplest case is a display, displays processed information, for example, the size of an object or the distance to it, or the target itself and its surroundings. Radio waves travel through space at the speed of light. Therefore, knowing the time t
From the emission of a radio signal pulse to its return, the distance to the object can be determined. R=
cˑ
t/2
, Where With
– speed of light. Continuous-wave radar
emits high-frequency radio waves continuously. Therefore, the antenna also picks up a continuous reflected signal. In their operation, such radars use the Doppler effect. The essence of this effect is that the frequency of the signal reflected from an object moving towards the radar is higher than the frequency of the signal reflected from an object moving away from it, despite the fact that the frequency of the emitted signal is constant. Therefore, such radars are used to determine the parameters of a moving object. An example of a radar based on the Doppler effect is a radar used by traffic police to determine the speed of a moving vehicle. In search of an object, the directional beam of the radar antenna scans the space, describing a full circle, or selecting a specific sector. It can be directed along a helical line, in a spiral. The view can also be conical or linear. It all depends on the task he must perform. If it is necessary to constantly monitor a selected moving target, the radar antenna is constantly directed at it and rotates after it using special tracking systems. Radar stations were first used during World War II to detect military aircraft, ships and submarines. Thus, at the end of December 1943, radars installed on British ships helped detect a fascist battleship that left the port of Altenfiord in Norway at night to intercept military ships. The fire on the battleship was very accurate, and soon it sank. The first radars were not very advanced, unlike modern ones, which reliably protect the airspace from air raids and missile attacks, recognizing almost any military targets on land and at sea. Radar guidance is used in homing missiles for terrain recognition. Radars monitor the flights of intercontinental missiles. Radars have also found their application in civilian life. Pilots guiding ships through narrow straits and air traffic controllers at airports supervising the flights of civil aircraft cannot do without them. They are indispensable when sailing in conditions of limited visibility - at night or in bad weather. With their help, the topography of the bottom of seas and oceans is determined, and contamination of their surfaces is studied. Meteorologists use them to identify storm fronts and measure wind speed and clouds. On fishing vessels, radars help detect schools of fish. Very often radars, or radar stations (radars), are called radars. And although now this word has become independent, in fact it is an abbreviation that arose from the English words “ radiodetectionandranging », which means “radio detection and ranging” and reflects the essence of radar.Other pages
Literature and footnotes
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How did radar appear?
How does radar work?
Application of radars
