Mobile radar. Modern radar. At the stage of re-equipment

Modern warfare is swift and fleeting. Often the winner in a combat encounter is the one who is the first to be able to detect a potential threat and respond adequately to it. For more than seventy years, to search for the enemy on land, sea and in the air, a radar method has been used, based on the emission of radio waves and the registration of their reflections from various objects. Devices that send and receive such signals are called radar stations or radars.

The term "radar" is an English abbreviation (radio detection and ranging), which was put into circulation in 1941, but has long since become an independent word and entered most of the world's languages.

The invention of radar is, of course, a landmark event. The modern world is hard to imagine without radar stations. They are used in aviation, in maritime transportation, with the help of radar the weather is predicted, violators of traffic rules are identified, and the earth's surface is scanned. Radar systems (RLK) have found their application in the space industry and in navigation systems.

However, radars are most widely used in military affairs. It should be said that this technology was originally created for military needs and reached the stage of practical implementation just before the start of World War II. All the major countries participating in this conflict actively (and not without result) used radar stations for reconnaissance and detection of enemy ships and aircraft. It can be confidently asserted that the use of radars decided the outcome of several significant battles both in Europe and in the Pacific theater of operations.

Today, radars are used to solve an extremely wide range of military tasks, from tracking the launch of intercontinental ballistic missiles to artillery reconnaissance. Each aircraft, helicopter, warship has its own radar system. Radars are the backbone of the air defense system. The newest radar system with a phased array antenna will be installed on a promising Russian tank "Armata". In general, the variety of modern radars is amazing. These are completely different devices that differ in size, characteristics and purpose.

It can be said with confidence that today Russia is one of the recognized world leaders in the development and production of radars. However, before talking about the trends in the development of radar systems, a few words should be said about the principles of operation of radars, as well as the history of radar systems.

How Radar Works

Location is a method (or process) of determining the location of something. Accordingly, radar is a method of detecting an object or object in space using radio waves that are emitted and received by a device called a radar or radar.

The physical principle of operation of the primary or passive radar is quite simple: it transmits radio waves into space, which are reflected from surrounding objects and return to it in the form of reflected signals. Analyzing them, the radar is able to detect an object at a certain point in space, as well as show its main characteristics: speed, height, size. Any radar is a complex radio engineering device consisting of many components.

The structure of any radar includes three main elements: a signal transmitter, an antenna and a receiver. All radar stations can be divided into two large groups:

• impulse;
• continuous action.

The pulse radar transmitter emits electromagnetic waves for a short period of time (fractions of a second), the next signal is sent only after the first pulse returns back and hits the receiver. The pulse repetition frequency is one of the most important characteristics of a radar. Low frequency radars send out several hundred pulses per minute.

The pulse radar antenna works for both reception and transmission. After the signal is emitted, the transmitter turns off for a while and the receiver turns on. After receiving it, the reverse process occurs.

Pulse radars have both disadvantages and advantages. They can determine the range of several targets at once, such a radar can easily get by with one antenna, the indicators of such devices are simple. However, in this case, the signal emitted by such a radar should have a fairly high power. It can also be added that all modern tracking radars are made according to a pulsed scheme.

Pulse radar stations usually use magnetrons, or traveling wave tubes, as the signal source.

The radar antenna focuses the electromagnetic signal and directs it, picks up the reflected pulse and transmits it to the receiver. There are radars in which the reception and transmission of a signal are carried out by different antennas, and they can be located at a considerable distance from each other. The radar antenna is capable of emitting electromagnetic waves in a circle or working in a certain sector. The radar beam can be directed in a spiral or be shaped like a cone. If necessary, the radar can follow a moving target by constantly pointing the antenna at it with the help of special systems.

The functions of the receiver include processing the received information and transferring it to the screen, from which it is read by the operator.

In addition to pulse radars, there are also continuous-wave radars that constantly emit electromagnetic waves. Such radar stations use the Doppler effect in their work. It lies in the fact that the frequency of an electromagnetic wave reflected from an object that approaches the signal source will be higher than from a receding object. The frequency of the emitted pulse remains unchanged. Radars of this type do not fix stationary objects, their receiver picks up only waves with a frequency above or below the emitted one.

A typical Doppler radar is the radar used by traffic police to determine the speed of vehicles.

The main problem of continuous radars is the inability to use them to determine the distance to the object, but during their operation there is no interference from stationary objects between the radar and the target or behind it. In addition, Doppler radars are fairly simple devices that require low-power signals to operate. It should also be noted that modern radar stations with continuous radiation have the ability to determine the distance to the object. To do this, use the change in the frequency of the radar during operation.

One of the main problems in the operation of pulse radars is the interference that comes from stationary objects - as a rule, this is the earth's surface, mountains, hills. During the operation of airborne pulsed aircraft radars, all objects located below are “obscured” by the signal reflected from the earth's surface. If we talk about ground-based or shipborne radar systems, then for them this problem manifests itself in the detection of targets flying at low altitudes. To eliminate such interference, the same Doppler effect is used.

In addition to primary radars, there are so-called secondary radars that are used in aviation to identify aircraft. The composition of such radar systems, in addition to the transmitter, antenna and receiver, also includes an aircraft transponder. When irradiated with an electromagnetic signal, the transponder gives additional information about the altitude, route, aircraft number, and its nationality.

Also, radar stations can be divided by the length and frequency of the wave on which they operate. For example, to study the surface of the Earth, as well as to work at considerable distances, waves of 0.9-6 m (frequency 50-330 MHz) and 0.3-1 m (frequency 300-1000 MHz) are used. For air traffic control, a radar with a wavelength of 7.5-15 cm is used, and over-the-horizon radars of missile launch detection stations operate at waves with a wavelength of 10 to 100 meters.

History of radar

The idea of ​​radar arose almost immediately after the discovery of radio waves. In 1905, Christian Hülsmeyer, an employee of the German company Siemens, created a device that could detect large metal objects using radio waves. The inventor suggested installing it on ships so that they could avoid collisions in conditions of poor visibility. However, ship companies were not interested in the new device.

Experiments with radar were also carried out in Russia. As early as the end of the 19th century, the Russian scientist Popov discovered that metal objects prevent the propagation of radio waves.

In the early 1920s, American engineers Albert Taylor and Leo Young managed to detect a passing ship using radio waves. However, the state of the radio engineering industry of that time was such that it was difficult to create industrial models of radar stations.

The first radar stations that could be used to solve practical problems appeared in England around the mid-1930s. These devices were very large and could only be installed on land or on the deck of large ships. It was not until 1937 that a miniature radar prototype was created that could be installed on an aircraft. By the start of World War II, the British had an deployed chain of radar stations called Chain Home.

Engaged in a new promising direction in Germany. And, I must say, not without success. Already in 1935, the Commander-in-Chief of the German Navy, Raeder, was shown a working radar with a cathode-beam display. Later, production models of the radar were created on its basis: Seetakt for the naval forces and Freya for air defense. In 1940, the Würzburg radar fire control system began to enter the German army.

However, despite the obvious achievements of German scientists and engineers in the field of radar, the German army began to use radar later than the British. Hitler and the top of the Reich considered radars to be exclusively defensive weapons, which the victorious German army did not really need. It is for this reason that by the beginning of the Battle of Britain, the Germans had deployed only eight Freya radar stations, although in terms of their characteristics they were at least as good as their British counterparts. In general, it can be said that it was the successful use of radar that largely determined the outcome of the Battle of Britain and the subsequent confrontation between the Luftwaffe and the Allied Air Force in the skies of Europe.

Later, the Germans, based on the Würzburg system, created an air defense line, which was called the Kammhuber Line. Using special forces units, the Allies were able to unravel the secrets of the German radar, which made it possible to effectively jam them.

Despite the fact that the British entered the "radar" race later than the Americans and Germans, at the finish line they managed to overtake them and approach the beginning of World War II with the most advanced radar detection system for aircraft.

Already in September 1935, the British began to build a network of radar stations, which already included twenty radar stations before the war. It completely blocked the approach to the British Isles from the European coast. In the summer of 1940, British engineers created a resonant magnetron, which later became the basis of airborne radar stations installed on American and British aircraft.

Work in the field of military radar was also carried out in the Soviet Union. The first successful experiments on detecting aircraft using radar stations in the USSR were carried out as early as the mid-1930s. In 1939, the first RUS-1 radar was adopted by the Red Army, and in 1940 - RUS-2. Both of these stations were put into mass production.

The Second World War clearly showed the high efficiency of the use of radar stations. Therefore, after its completion, the development of new radars became one of the priority areas for the development of military equipment. Over time, airborne radars were received by all military aircraft and ships without exception, radars became the basis for air defense systems.

During the Cold War, the United States and the USSR acquired a new destructive weapon - intercontinental ballistic missiles. Detecting the launch of these missiles became a matter of life and death. Soviet scientist Nikolai Kabanov proposed the idea of ​​using short radio waves to detect enemy aircraft at long distances (up to 3,000 km). It was quite simple: Kabanov found out that radio waves 10-100 meters long are capable of being reflected from the ionosphere, and irradiating targets on the earth's surface, returning the same way to the radar.

Later, based on this idea, radars for over-the-horizon detection of ballistic missile launches were developed. An example of such radars is Daryal, a radar station that for several decades was the basis of the Soviet missile launch warning system.

Currently, one of the most promising areas for the development of radar technology is the creation of a radar with a phased antenna array (PAR). Such radars have not one, but hundreds of radio wave emitters, which are controlled by a powerful computer. Radio waves emitted by different sources in the phased array can amplify each other if they are in phase, or, conversely, weaken.

The phased array radar signal can be given any desired shape, it can be moved in space without changing the position of the antenna itself, and work with different radiation frequencies. A phased array radar is much more reliable and sensitive than a conventional antenna radar. However, such radars also have disadvantages: the cooling of the radar with phased array is a big problem, in addition, they are difficult to manufacture and expensive.

New phased array radars are being installed on fifth-generation fighters. This technology is used in the US missile attack early warning system. The radar complex with PAR will be installed on the newest Russian tank "Armata". It should be noted that Russia is one of the world leaders in the development of PAR radars.

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In the military news report of the Vietnamese TV channel QPVN, for the first time, the 55Zh6U Nebo-UE three-coordinate standby radar for detecting and tracking airborne objects of the meter range, developed by the Nizhny Novgorod Research Institute of Radio Engineering (Russia), was demonstrated. Previously, the supply of radar data to Vietnam was not reported.

Video from youtube.com/ https://www.youtube.com/embed/u47XQqILh_I

One of the protection systems began to work in the Arctic. A tracking station that even sees a soccer ball from space. In February 2019, an ultra-modern radar installation of the Voronezh family was put into operation in the Komi Republic. It can very accurately determine the parameters of flying targets. Nobody has seen the station yet, except for the creators and employees. The film crew of Channel One was the first to be shown a unique structure that looks more like a futuristic art object, and not a formidable deterrent and warning system for a nuclear strike.

Radar station "Nebo-U" took up duty near Saratov. It made it possible to tighten control of the airspace in the area of ​​responsibility of local anti-aircraft missile units and increase the radius of target detection. The press service of the Central Military District reported on March 28.

With the help of this radar, the military can now quickly detect, take coordinates and track targets in the sky at an altitude of up to 80 kilometers and a range of up to 600 kilometers. The target they can follow can move up to Mach 8. The station is able to track up to 200 targets - from aircraft and drones to cruise and guided missiles. It even allows you to remotely determine their nationality and carry out direction finding of active jammers.

Radar "Nebo-U" is the most advanced station in its class in the world.

A mobile radar complex (RLK) "Rezonans-N" with elements of artificial intelligence was deployed in the Arctic. As the Ministry of Defense explained to Izvestia, such technologies are important for the Arctic region, from where a potential enemy can strike at the Urals, Siberia and Central Russia.

The Russian Defense Ministry was able to control the airspace over Europe to a greater depth. In the Kovylkinsky district of Mordovia, a new-generation over-the-horizon detection radar station of the Container type took up experimental combat duty on December 1, the press service of the Russian Defense Ministry reports.

A new-generation over-the-horizon detection radar of the Container type can detect a massive take-off of hypersonic cruise missiles or aircraft at a distance of more than two thousand kilometers from the borders of Russia, Lieutenant General Andrey Demin, commander of the 1st Air Defense Army, said.

“The capabilities of this station make it possible to observe air targets far beyond the Russian border, at a distance of more than two thousand kilometers. This station will allow the Russian Armed Forces and the top military-political leadership, receiving information about these targets, to reveal a possible plan or attempt of a mass take-off of cruise missiles and a flight towards the Russian border, a mass take-off of aviation and, in the future, hypersonic cruise missiles that the enemy is developing, in direction of Russia,” Demin said.

The military unit of the radio engineering troops of the Air Force and Air Defense Association of the Eastern Military District on the Kamchatka Peninsula received a modern radar station (RLS) P-18R.

The radar is designed to detect airborne objects, measure their range, azimuth and radial velocity, automatically track targets, automatically recognize their class, as well as transmit radar information to an integrated control system.

The advantages of the radar station that came into service are high detection range and accuracy in determining the coordinates of targets, effective detection of air objects made using Stealth technology, increased noise immunity and reliability.

The equipment will be put into operation in the near future.

The modernized radar stations (RLS) "Gamma-S1M" and "Nebo-UM" took up combat duty in the air defense unit of the Central Military District (TsVO) in the Samara Region.

Radars of medium and high altitudes entered the Central Military District under the state defense order-2018. They are designed to detect, measure coordinates and track air targets of various categories at a distance of up to 600 km - from aircraft to cruise and guided missiles, including small-sized, hypersonic and ballistic missiles.

Station equipment allows you to determine the nationality of the object and transmit information to the command post or anti-aircraft systems. In addition, it is possible to find sources of interference and determine their location.

The crews of radar stations and automation systems of the air defense connection underwent a training course to work with new types of equipment.

The formations and military units of the Eastern Military District continue to receive modern and promising military equipment of the new generation.

Over the current month, several units of the latest radar stations, in particular, radar stations (RLS) "Niobium", "Casta" have been received by air defense formations of the Air Defense Forces.

Modern samples of the Niobium and Casta radar stations are capable of monitoring airspace, determining coordinates and identifying air targets, and transmitting their movement parameters to air defense control systems.

In the near future, the Air Defense Forces of the Eastern Military District will receive another newest station - a mobile radio altimeter for determining the flight altitude of aircraft.

As part of the re-equipment program for the troops of the Southern Military District (SMD), the radio engineering regiment of the 4th Air Force and Air Defense Army of the SMD, stationed in the Volgograd Region, received a new Kasta-2 radar station (RLS).

Radar "Casta-2" is a mobile radar station with a circular view of the standby mode. The station is designed to control airspace, determine the 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.

The Russian radar stations (RLS) deployed in Crimea make it possible to control the situation in the airspace over the entire Black Sea. High-precision systems 55Zh6M "Nebo-M" are capable of detecting a wide range of complex targets - from aircraft and helicopters to cruise missiles and hypersonic vehicles. Such complexes are mounted on vehicles and can be quickly deployed in any part of the peninsula. In Syria, 55ZH6M proved to be highly effective at the Khmeimim airbase.

A new modification of the Podsolnukh radar station has been created for the Russian military, which will be able to operate in the Arctic, the developer said on Monday.

The 1L122 mobile three-coordinate radar station for detecting air targets guards the Syrian sky. Information about this was published by Syrian sources, posting this photo as an illustration. On it we see a radar mounted on an MT-LBu tracked carrier. The equipment at the position is guarded by a Syrian soldier. For reasons of secrecy, the background of the surrounding area is "camouflaged".

In the Kirov region, the latest Gamma-S1 radar station has taken up combat duty, the press service of the Central Military District reports.

The report of the Central Military District says that the Gamma-S1 radar is designed to control airspace with a viewing area from ten to 300 kilometers.

The calculation includes four people, the deployment time is no more than 40 minutes.

Earlier it was reported that the units of the radio engineering troops of the Aerospace Forces received more than 70 of the latest radar stations, large and small, in 2017, including Nebo-M, Opponent, All-Altitude Detector, Sopka-2 , "Approach-K1" and "Approach-M", "Casta-2-2", "Gamma-C1".

The units of the radio engineering troops of the Aerospace Forces received more than 70 newest radar stations in 2017. Among them are the latest radar systems of medium and high altitudes "Nebo-M", radar stations of medium and high altitudes "Opponent", "All-altitude detector", "Sopka-2", low-altitude radar stations "Podlet-K1" and "Podlet-M ”, “Casta-2-2”, “Gamma-C1”, as well as modern complexes of automation equipment “Foundation” and other means.

Radars are designed to recognize air objects, as well as determine their parameters, such as range, speed, altitude, and determine state affiliation.

New models of weapons of the radio engineering troops, unlike radar equipment of previous generations, are created on a modern element base, with maximum automation of all processes and operations of combat work and, consequently, high combat effectiveness combined with ease of use and maintenance.

All modern radars are distinguished by high noise immunity, the ability to perform the task of conducting radar reconnaissance at any position, and increased capabilities for detecting various classes of targets.

The new mobile radar "Casta 2-2", capable of detecting stealth objects, has taken up combat duty to control airspace in the Volga region. The station strengthened the combat capabilities of the units of the radio engineering troops of the Central Military District stationed in the Orenburg region.

Radar "Casta 2-2" - a mobile radar station with a circular view of the standby mode. Designed to control the airspace, determine the range, azimuth, flight altitude and route characteristics of aircraft, helicopters, cruise missiles, including those flying at low and extremely low altitudes. The station detects targets made using Stealth technologies, as well as moving objects on the sea surface.

Three new Voronezh radar stations in the Krasnoyarsk and Altai Territories and the Orenburg Region have taken up combat duty, the commander of the Space Forces said on Wednesday. Earlier, he reported that the stations in these regions are on experimental combat duty.

“Yes, for the first time in the history of the Armed Forces of the Russian Federation, three of the latest Voronezh radar stations of the missile attack warning system, created using high factory readiness technology in the Krasnoyarsk, Altai Territories and the Orenburg Region, took up combat duty for radar control in the established areas of responsibility” , said the commander.

Artillerymen of the combined arms army of the Western Military District stationed in the Moscow Region received the latest Zoopark ground artillery reconnaissance stations.

As part of the state defense order, two radio engineering regiments of the Western Military District (ZVO), stationed in the Leningrad Region and Karelia, received the latest medium and high-altitude radar stations (RLS) of the Nebo-UM duty mode.

"Nebo-UM" is a further development of the "Nebo-U" radar system with a modified composition of equipment, made on a new element base.

The radar is designed to monitor the airspace, detect various targets and determine their coordinates. The station is capable of finding and tracking both aerodynamic (airplanes, helicopters, cruise missiles, etc.) and ballistic (missile warheads) targets.

The station equipment allows you to detect a target, determine its coordinates and nationality, and transmit information to a command post or anti-aircraft systems. In addition, it is possible to find sources of interference and determine their location.

The personnel of the crews of radar stations and automation systems underwent a planned retraining for new models and equipment and by the end of the year will take up combat duty to protect air borders in the North-West of Russia.

The radio-technical regiment of the Western Military District (ZVO), stationed in the Leningrad Region, has received a new radar station (RLS) Casta 2-2.

Radar "Casta 2-2" - a mobile radar station with a circular view of the standby mode. It is designed to control airspace, determine the 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. The station detects targets made using Stealth technologies, as well as moving objects on the sea surface.

"Casta 2-2" has high reliability, convenience and safety in operation, ease of maintenance, in terms of the combination of characteristics it has no analogues in the world.

In addition to the stations themselves, the ZVO units are equipped with radio-transparent shelters, remote operator workstations and automation equipment.

New radar stations (RLS) "Nebo-U" and "Nebo-M" entered the 14th Army of the Air Force and Air Defense of the Central Military District under the State Defense Order.

The stations reinforced the units of the district's radio engineering troops stationed in the Volga region and Western Siberia.

Captain M. Vinogradov,
candidate of technical sciences

Modern radar facilities installed on aircraft and spacecraft currently represent one of the most intensively developing segments of electronic technology. The identity of the physical principles underlying the construction of these tools makes it possible to consider them within the framework of one article. The main differences between space and aviation radars lie in the principles of radar signal processing associated with different aperture sizes, the propagation of radar signals in different layers of the atmosphere, the need to take into account the curvature of the earth's surface, etc. Despite such differences, the developers of radars with synthesizing aperture (RSA) make every effort to achieve the maximum similarity of the capabilities of these reconnaissance assets.

At present, airborne radars with aperture synthesis make it possible to solve the tasks of specific reconnaissance (to survey the earth's surface in various modes), select mobile and stationary targets, analyze changes in the ground situation, survey objects hidden in forests, and detect buried and small marine objects.

The main purpose of SAR is a detailed survey of the earth's surface.

Rice. Fig. 1. Shooting modes of modern SAR (a - detailed, b - overview, c - scanning)	Rice. 2. Examples of real radar images with resolutions of 0.3 m (top) and 0.1 m (bottom)
Rice. 3. View of images at different levels of detail
Rice. Fig. 4. Examples of fragments of real areas of the earth's surface obtained at the levels of detail DTED2 (left) and DTED4 (right)

Due to the artificial increase in the aperture of the onboard antenna, the basic principle of which is the coherent accumulation of the reflected radar signals over the synthesis interval, it is possible to obtain a high resolution in angle. In modern systems, resolution can reach tens of centimeters when operating in the centimeter wavelength range. Similar values ​​of range resolution are achieved through the use of intra-pulse modulation, for example, linear frequency modulation (chirp). The interval for synthesizing the antenna aperture is directly proportional to the flight altitude of the SAR carrier, which ensures that the survey resolution is independent of altitude.

At present, there are three main modes of surveying the earth's surface: overview, scanning, and detailed (Fig. 1). In the survey mode, the survey of the earth's surface is carried out continuously in the capture band, while separating the lateral and anterolateral modes (depending on the orientation of the main lobe of the antenna pattern). The accumulation of the signal is carried out for a time equal to the calculated interval for synthesizing the antenna aperture for the given flight conditions of the radar carrier. The scanning shooting mode differs from the survey one in that the shooting is carried out over the entire width of the swath, in strips equal to the width of the capture swath. This mode is used exclusively in space-based radars. When shooting in the detailed mode, the signal accumulation is carried out at an interval increased compared to the overview mode. The increase in the interval is carried out due to the movement of the main lobe of the antenna pattern, synchronous with the movement of the radar carrier, so that the irradiated area is constantly in the shooting area. Modern systems make it possible to obtain images of the earth's surface and objects located on it with resolutions of the order of 1 m for overview and 0.3 m for detailed modes. The Sandia company announced the creation of a SAR for tactical UAVs, which has the ability to shoot with a resolution of 0.1 m in detailed mode. The resulting characteristics of the SAR (in terms of surveying the earth's surface) are significantly affected by the methods used for digital processing of the received signal, an important component of which are adaptive algorithms for correcting trajectory distortions. It is the impossibility of maintaining a rectilinear trajectory of the carrier for a long time that does not make it possible to obtain resolutions comparable to the detailed mode in the continuous survey mode, although there are no physical restrictions on the resolution in the survey mode.

The mode of inverse aperture synthesis (IRSA) allows synthesizing the antenna aperture not due to the movement of the carrier, but due to the movement of the irradiated target. In this case, we can talk not about the translational movement characteristic of terrestrial objects, but about the pendulum movement (in different planes), characteristic of floating craft swinging on the waves. This feature determines the main purpose of IRSA - the detection and identification of marine objects. The characteristics of modern IRSAs make it possible to confidently detect even small objects, such as submarine periscopes. All aircraft in service with the US Armed Forces and other states, whose tasks include patrolling the coastal zone and water areas, are able to shoot in this mode. The images obtained as a result of shooting are similar in their characteristics to the images obtained as a result of shooting with direct (non-inverse) aperture synthesis.

Interferometric survey mode (Interferometric SAR - IFSAR) allows you to get three-dimensional images of the earth's surface. At the same time, modern systems have the ability to conduct single-point shooting (that is, use one antenna) to obtain three-dimensional images. To characterize image data, in addition to the usual resolution, an additional parameter is introduced, called height accuracy, or height resolution. Depending on the value of this parameter, several standard gradations of three-dimensional images (DTED - Digital Terrain Elevation Data) are defined:
DTEDO.............................. 900 m
DTED1.............................. 90m
DTED2.............................. 30m
DTED3..............................10m
DTED4...............Sm
DTED5..............................1m

The type of images of an urbanized area (model) corresponding to different levels of detail is shown in fig. 3.

Levels 3-5 are officially known as HRTe-High Resolution Terrain Elevation data. The determination of the location of ground objects on images of level 0-2 is carried out in the WGS 84 coordinate system, the height is measured relative to the zero mark. The coordinate system of high-resolution images is not currently standardized and is under discussion. On fig. Figure 4 shows fragments of real areas of the earth's surface obtained as a result of stereo imaging with different resolutions.

In 2000, the American Shuttle, within the framework of the SRTM (Shuttle Radar Topography Mission) project, the purpose of which was to obtain cartographic information on a large scale, performed an interferometric survey of the equatorial part of the Earth in the band from 60 ° N. sh. to 56°S sh., having received at the output a three-dimensional model of the earth's surface in the DTED2 format. To obtain detailed 3D data in the US, the NGA HRTe? within which images of levels 3-5 will be available.
In addition to radar imaging of open areas of the earth's surface, the airborne radar has the ability to obtain images of scenes hidden from the observer's eyes. In particular, it allows you to detect objects hidden in forests, as well as those located underground.

Penetrating radar (GPR, Ground Penetrating Radar) is a remote sensing system, the principle of which is based on the processing of signals reflected from deformed or different in composition areas located in a homogeneous (or relatively homogeneous) volume. The earth surface sounding system makes it possible to detect voids, cracks, buried objects located at different depths, to identify areas of different density. In this case, the energy of the reflected signal strongly depends on the absorbing properties of the soil, the size and shape of the target, and the degree of heterogeneity of the boundary regions. At present, GPR, in addition to its military-applied orientation, has developed into a commercially viable technology.

Sounding of the earth's surface occurs by irradiation with pulses with a frequency of 10 MHz - 1.5 GHz. The irradiating antenna may be located on the earth's surface or located on board the aircraft. Part of the irradiation energy is reflected from changes in the subsurface structure of the earth, while a large part penetrates further into the depths. The reflected signal is received, processed, and the processing results are shown on the display. When the antenna moves, a continuous image is generated that reflects the state of the subsurface soil layers. Since, in fact, reflection occurs due to the difference in the dielectric constants of various substances (or different states of one substance), probing can reveal a large number of natural and artificial defects in a homogeneous mass of subsurface layers. The depth of penetration depends on the condition of the soil at the site of irradiation. The decrease in signal amplitude (absorption or scattering) largely depends on a number of soil properties, the main of which is its electrical conductivity. Thus, sandy soils are optimal for sounding. Clay and very moist soils are much less suitable for this. Good results are shown by probing dry materials such as granite, limestone, concrete.

The sounding resolution can be improved by increasing the frequency of the emitted waves. However, an increase in frequency adversely affects the penetration depth of the radiation. So, signals with a frequency of 500-900 MHz can penetrate to a depth of 1-3 m and provide a resolution of up to 10 cm, and with a frequency of 80-300 MHz they penetrate to a depth of 9-25 m, but the resolution is about 1.5 m.

The main military purpose of subsurface sounding radar is the detection of planted mines. At the same time, the radar installed on board an aircraft, such as a helicopter, allows you to directly open maps of minefields. On fig. Figure 5 shows images from a helicopter-mounted radar showing the location of anti-personnel mines.

Airborne radar, designed to detect and track objects hidden in forests (FO-PEN - FOliage PENetrating), allows you to detect small objects (moving and stationary), hidden by tree crowns. Shooting objects hidden in forests is carried out similarly to conventional shooting in two modes: overview and detail. On average, in the overview mode, the capture bandwidth is 2 km, which makes it possible to obtain images of 2x7 km of the earth's surface at the output; in the detailed mode, the survey is carried out in sections of 3x3 km. The shooting resolution depends on the frequency and varies from 10 m at a frequency of 20-50 MHz to 1 m at a frequency of 200-500 MHz.

Modern methods of image analysis make it possible to detect and subsequently identify objects in the received radar image with a sufficiently high probability. At the same time, detection is possible on images with both high (less than 1 m) and low (up to 10 m) resolution, while recognition requires images with a sufficiently high (about 0.5 m) resolution. And even in this case, we can talk for the most part only about recognition by indirect signs, since the geometric shape of the object is very strongly distorted due to the presence of a signal reflected from the leaf cover, as well as due to the appearance of signals with a frequency shift due to the Doppler effect that occurs in the result of leaves swaying in the wind.

On fig. 6 shows images (optical and radar) of the same area. Objects (column of cars) invisible on the optical image are clearly visible on the radar image; the geometric structure of the object is completely absent.

The detail of the obtained radar images made it possible to implement in practice a number of features, which, in turn, made it possible to solve a number of important practical problems. One of these tasks is tracking changes that have occurred on a certain area of ​​the earth's surface over a certain period of time - coherent detection. The duration of the period is usually determined by the frequency of patrolling a given area. Tracking of changes is carried out on the basis of the analysis of coordinate-wise combined images of a given area, obtained sequentially one after another. In this case, two levels of analysis detail are possible.

Fig. 5. Maps of minefields in three-dimensional representation when shooting in different polarizations: a model (on the right), an example of an image of a real area of ​​the earth's surface with a complex subsurface situation (on the left), obtained using a radar installed on board a helicopter
Rice. Fig. 6. Optical (above) and radar (below) images of a section of terrain with a convoy of cars moving along a forest road

The first level involves the detection of significant changes and is based on the analysis of the amplitude readings of the image, which carry the main visual information. Most often, this group includes changes that a person can see when simultaneously viewing two generated radar images. The second level is based on the analysis of phase readings and makes it possible to detect changes invisible to the human eye. These include the appearance of traces (of a car or a person) on the road, a change in the state of windows, doors (“open - closed”), etc.

Another interesting SAR capability, also announced by Sandia, is radar video recording. In this mode, the discrete formation of the antenna aperture from section to section, which is characteristic of the continuous survey mode, is replaced by parallel multichannel formation. That is, at each moment of time, not one, but several (the number depends on the tasks being solved) apertures are synthesized. A kind of analogue of the number of formed apertures is the frame rate in conventional video recording. This feature allows you to implement the selection of moving targets based on the analysis of the received radar images, using the principles of coherent detection, which is essentially an alternative to standard radars that select moving targets based on the analysis of Doppler frequencies in the received signal. The effectiveness of the implementation of such selectors of moving targets is very doubtful due to significant hardware and software costs, therefore, such modes will most likely remain nothing more than an elegant way to solve the selection problem, despite the opening opportunities to select targets moving at very low speeds (less than 3 km/h). h, which is inaccessible to Doppler SDCs). Direct video recording in the radar range has also not found application at the present time, again due to high requirements for speed, therefore there are no existing models of military equipment that implement this mode in practice.

A logical continuation of improving the technique of surveying the earth's surface in the radar range is the development of subsystems for analyzing the received information. In particular, the development of systems for automatic analysis of radar images, which make it possible to detect, distinguish and recognize ground objects that have fallen into the survey area, is of great importance. The complexity of creating such systems is associated with the coherent nature of radar images, the phenomena of interference and diffraction in which lead to the appearance of artifacts - artificial glare, similar to those that appear when a target with a large effective scattering surface is irradiated. In addition, the quality of the radar image is somewhat lower than the quality of a similar (by resolution) optical image. All this leads to the fact that there are currently no effective implementations of algorithms for recognizing objects in radar images, but the number of works carried out in this area, certain successes achieved recently, suggest that in the near future it will be possible to talk about intelligent unmanned reconnaissance vehicles that have the ability to assess the ground situation based on the results of the analysis of information received by their own airborne radar reconnaissance equipment.

Another direction of development is integration, that is, a coordinated combination with subsequent joint processing of information from several sources. These can be radars shooting in various modes, or radars and other reconnaissance equipment (optical, infrared, multispectral, etc.).

Thus, modern radars with antenna aperture synthesis allow solving a wide range of tasks related to conducting radar surveys of the earth's surface, regardless of the time of day and weather conditions, which makes them an important means of obtaining information about the state of the earth's surface and objects located on it.

Foreign military review No. 2 2009 P. 52-56

MILITARY UNIVERSITY MILITARY ANTI-AIR

DEFENSE OF THE ARMED FORCES OF THE RUSSIAN FEDERATION

(branch, Orenburg)

Department of Radar Weapons (Reconnaissance Radar and ACS)

Ex. No. _____

The device and operation of the reconnaissance radar Part one The device of the 9s18m1 radar

Approved as a textbook

for cadets and university students,

training centers, formations and units

military air defense

Armed Forces of the Russian Federation

the textbook is intended for cadets and students of universities, training centers, formations and units of the military air defense of the Armed Forces of the Russian Federation, who study the device and operation of reconnaissance radar stations.

The first part of the textbook contains information about the 9S18M1 radar station.

In the second part about the radar station 1L13.

In the third, about the 9S15M, 9S19M2, 35N6 radar stations and the 9S467-1M radar information processing post.

A feature of the textbook is the systematized presentation of educational material from general to particular in accordance with the sequence of passing the discipline “Design and operation of reconnaissance radar” at the Military University of the Air Defense Forces of the RF Armed Forces (branch, Orenburg), as well as using the experience gained at the Department of Radar Weapons and in the troops.

Part 1 of the textbook was developed by the team of authors of the Military University of the Military Air Defense Forces of the Russian Federation (branch, Orenburg), under the guidance of Candidate of Military Sciences, Associate Professor, Major General L. Chukin. M.

The work was attended by: Candidate of Military Sciences, Associate Professor, Colonel Shevchun FN; Candidate of Military Sciences, Associate Professor, Lieutenant Colonel Shchipakin A.Yu.; lieutenant colonel Golchenko I.P.; lieutenant colonel Kalinin D.V.; Associate Professor, Lieutenant Colonel Yu.I. Lyapunov; Candidate of Pedagogical Sciences, Captain Sukhanov P.V.; Candidate of Technical Sciences, Captain Rychkov A.V.; lieutenant colonel Grigoriev G.A.; candidate of pedagogical sciences, lieutenant colonel Dudko A.V.

Approved as a textbook on the discipline "Design and operation of reconnaissance radar" by the head of the military air defense of the RF Armed Forces.

This textbook is the first edition, and the team of authors hopes that possible shortcomings in it will not be a serious hindrance for readers and thanks for the feedback and suggestions aimed at improving the textbook. All feedback and suggestions will be taken into account in the preparation of its next edition.

Our address and phone number: 460010, Orenburg, st. Pushkinskaya 63, FVU RF Armed Forces, Department of Radar Weapons; tel. 8-353-2-77-55-29 (switchboard), 1-23 (department).

Introduction 5

List of abbreviations and symbols 7

I. General information about the 9S18M1 radar. Structural design and placement of the main components 9

1.1 Purpose, composition and design features of the 9S18M1 radar 10

1.2 Tactical and technical characteristics of the radar 12

1.3 Radar operating modes 14

1.4 Structural design and placement of the main components of the radar 17

II. Radar equipment 9S18M1

2.1 Brief description of devices and systems of radar equipment 24

2.2 The operation of the 9S18M1 radar according to the block diagram 26

2.3 The operation of the 9S18M1 radar according to the structural and functional scheme 31

2.4 Organization of the overview of space 44

2.5 Power supply system 53

2.6 9S18M1 radar transmitter. Liquid cooling system 79

2.7 Antenna device radar 9S18M1. Waveguide-feeder device 91

2.8 Radar receiver 9S18M1 102

2.9 Radar jamming device 9S18M1 114

2.10 Radar processing and control device 9S18M1 126

2.10.1 Synchronization and interface equipment 139

2.10.2 Equipment for processing radar information radar 9S18M1 150

2.10.3 Radar operator console 9S18M1 153

2.10.4 Specialized digital computing device 160

2.11 General information about the ground radar interrogator 167

2.12 Display device 171

2.13 Communication equipment 187

2.14 External and internal communication equipment 195

2.15 Antenna-rotating device radar 9S18M1 201

2.16 Radar antenna deployment and folding device

2.17 Radar air cooling system 9S18M1 216

2.18 Equipment for navigation, orientation and topographical positioning radar 9S18M1 223

III. General information about the base machine radar 9S18M1 243

IV. General information about the means of maintenance and repair of the radar 9S18M1 261

4.1 Built-in system for monitoring and troubleshooting radar 9S18M1 261

4.2 Purpose, composition and placement of spare parts and accessories. The procedure for finding the necessary element in the ZIP 272

4.3 Purpose, composition and capabilities for maintenance and repair of MRTO 9V894 275

The work is headed by the head of the working group of the Scientific and Technical Council of the Military-Industrial Commission for Radio Photonics Alexei Nikolaevich Shulunov. The first steps that can be considered successful have been taken. It seems that a new era is opening in classical radar, which now seems like science fiction.

Probably everyone who graduated from at least high school knows what radar is. And what constitutes a radio-photon location is known not to a very large circle of specialists. To put it simply, the new technology allows you to combine the incompatible - the radio wave and light. In this case, the flow of electrons must be converted into a flow of photons and vice versa. The task, which yesterday was beyond reality, can be solved in the near future. What will it give?

For example, the basis of radar systems for missile defense and tracking of space objects are huge radar complexes. The premises in which the equipment is located are multi-storey buildings. The use of photonic technologies will make it possible to fit all control and data processing systems in a much smaller size - literally in a few rooms. At the same time, the technical capabilities of radars to detect even small objects at a distance of thousands of kilometers will only increase. Moreover, due to the use of photonic technologies, not a target mark will appear on the radar screen, but its image, which is unattainable with classical radar. That is, instead of the usual luminous dot, the operator will see what is really flying - an airplane, a rocket, a flock of birds or a meteorite, it is worth repeating, even thousands of kilometers from the radar.

On the screen of the photon radar, not the mark of the target will appear, but its image, which is unattainable with classical radar

Now all radar systems - military and civilian - operate in a strictly defined frequency range, which complicates the technical design and leads to a variety of radar nomenclature. Photon radars will achieve the highest degree of unification. They are able to instantly tune in a very wide range of operating frequencies - from meters to millimeters.

It has long been no secret that the so-called stealth aircraft are also clearly visible in the meter range, but their coordinates are most accurately given out by stations in the centimeter and millimeter ranges. Therefore, in air defense systems, both meter stations with very large antennas and more compact centimeter ones work at the same time. But a photon radar, scanning space in a long frequency range, will detect the same "invisibility" without any problems and, instantly retuning to a broadband signal and a high frequency, will determine its exact coordinates in height and range.

It's just about the location. Revolutionary changes will also take place in electronic warfare, in the transmission of information and its protection, in computing technologies and much more. It is easier to say that radio photonics will not affect.

In fact, a fundamentally new branch of high-tech industry will be created. The task is the most complicated, therefore many leading research centers of the country, university science, a number of industrial enterprises are involved in its solution. According to Shulunov, the work is carried out in close connection with the Ministry of Defense, the Ministry of Economic Development, the Ministry of Science and Education. Recently, the president of Russia took them under his control.