The radar emits electromagnetic energy and detects echoes coming from reflected objects and also determines their characteristics. The purpose of the course project is to consider the radar with a circular view and calculate the tactical indicators of this radar: maximum range, taking into account absorption; real resolution in range and azimuth; real accuracy of measuring range and azimuth. In the theoretical part, a functional diagram of a pulsed active radar of air targets for air traffic control is given.
Share your work on social media
If this work did not suit you at the bottom of the page there is a list of similar works. You can also use the search button
Radar systems (radars) are designed to detect and determine the current coordinates (range, speed, elevation and azimuth) of reflected objects.
The radar emits electromagnetic energy and detects echoes coming from reflected objects, as well as determines their characteristics.
The purpose of the course project is to consider the radar with a circular view and calculate the tactical indicators of this radar: maximum range, taking into account absorption; real resolution in range and azimuth; real accuracy of measuring range and azimuth.
In the theoretical part, a functional diagram of a pulsed active radar of air targets for air traffic control is given. The system parameters and formulas for its calculation are also given.
In the calculation part, the following parameters were determined: maximum range taking into account absorption, real resolution in range and azimuth, accuracy of measuring range and azimuth.
1. Theoretical part
1.1 Functional diagram of the radarall-round view
Radar - the field of radio engineering, providing radar observation of various objects, that is, their detection, measurement of coordinates and motion parameters, as well as the identification of some structural or physical properties by using radio waves reflected or re-emitted by objects or their own radio emission. Information obtained in the process of radar surveillance is called radar. Radio-technical radar surveillance devices are called radar stations (radars) or radars. The very same objects of radar observation are called radar targets or simply targets. When using reflected radio waves, radar targets are any inhomogeneities in the electrical parameters of the medium (dielectric and magnetic permeability, conductivity) in which the primary wave propagates. This includes aircraft (airplanes, helicopters, meteorological probes, etc.), hydrometeors (rain, snow, hail, clouds, etc.), river and sea vessels, ground objects (buildings, cars, airplanes at airports, etc.) ), all kinds of military objects, etc. Astronomical objects are a special type of radar targets.
The source of radar information is a radar signal. Depending on the methods of obtaining it, the following types of radar surveillance are distinguished.
- Passive response radar,based on the fact that the oscillations emitted by the radar - the sounding signal - are reflected from the target and enter the radar receiver in the form of a reflected signal. This type of surveillance is sometimes also referred to as active passive response radar.
Active response radar,called active radar with an active response, it is characterized by the fact that the response signal is not reflected, but re-emitted with the help of a special transponder - a repeater. At the same time, the range and contrast of radar observation are noticeably increased.
Passive radar is based on the reception of targets' own radio emission, mainly in the millimeter and centimeter ranges. If the probing signal in the two previous cases can be used as a reference signal, which provides the fundamental possibility of measuring the range and speed, then in this case there is no such possibility.
A radar system can be thought of as a radar channel like radio communication or telemetry channels. The main components of the radar are a transmitter, a receiver, an antenna device, and a terminal device.
The main stages of radar surveillance aredetection, measurement, resolution and recognition.
By detection is the process of making a decision about the presence of goals with an acceptable probability of an erroneous decision.
Measurement allows you to estimate the coordinates of targets and the parameters of their movement with permissible errors.
Permission is to perform tasks of detecting and measuring the coordinates of one target in the presence of others, closely spaced in range, speed, etc.
Recognition makes it possible to establish some characteristic features of the target: it is point or group, moving or group, etc.
Radar information from the radar is broadcast by radio or cable to the control center. The process of tracking the radar for individual targets is automated and carried out using a computer.
Aircraft navigation along the route is provided by the same radars that are used in ATC. They are used both to control the maintenance of a given path, and to determine the position during flight.
To carry out the landing and its automation, along with radio beacon systems, landing radars are widely used, which provide tracking of the deviation of the aircraft from the course and glide path.
A number of airborne radar devices are also used in civil aviation. This, first of all, includes an airborne radar for detecting dangerous meteorological formations and obstacles. Usually, it also serves to survey the earth in order to provide the possibility of autonomous navigation along characteristic ground-based radar landmarks.
Radar systems (radars) are designed to detect and determine the current coordinates (range, speed, elevation and azimuth) of reflected objects. The radar emits electromagnetic energy and detects echoes coming from reflected objects, as well as determines their characteristics.
Let us consider the operation of a pulsed active radar for detecting air targets for air traffic control (ATC), the structure of which is shown in Figure 1. The view control device (antenna control) is used to view space (usually a circular) antenna beam, narrow in the horizontal plane and wide in the vertical one.
In the radar under consideration, a pulsed radiation mode is used, therefore, at the end of the next sounding radio pulse, the only antenna switches from the transmitter to the receiver and is used for reception until the next sounding radio pulse starts to be generated, after which the antenna is reconnected to the transmitter, and so on.
This operation is performed by a transmit-receive switch (RFP). The trigger pulses that set the repetition period of the probing signals and synchronize the operation of all radar subsystems are generated by the synchronizer. The signal from the receiver, after the analog-to-digital converter (ADC), goes to the information processing equipment - the signal processor, where the primary information processing is performed, which consists in detecting the signal and changing the coordinates of the target. Target marks and trajectory traces are formed during the primary processing of information in the data processor.
The generated signals, together with information about the angular position of the antenna, are transmitted for further processing to the command post, as well as for monitoring the circular view indicator (IKO). With autonomous operation of the radar, the IKO serves as the main element for observing the air situation. Such a radar usually processes information in digital form. For this, a device for converting a signal into a digital code (ADC) is provided.
Figure 1 Functional diagram of the radar of a circular view
1.2 Definitions and basic parameters of the system. Calculation formulas
The main tactical characteristics of the radar
Maximum range
The maximum operating range is set by tactical requirements and depends on many technical characteristics of the radar, the conditions of radio wave propagation and the characteristics of targets, which are subject to random changes in the real conditions of using the stations. Therefore, the maximum range is a probabilistic characteristic.
The free-space range equation (that is, without taking into account the influence of the earth and absorption in the atmosphere) for a point target establishes a relationship between all the basic parameters of the radar.
where E rad - energy emitted in one pulse;
S a - effective antenna area;
S epho - effective reflective target area;
is the wavelength;
to p - the discrimination factor (the ratio of the signal-to-noise energy at the receiver input, at which signals are received with a given probability of correct detection W by and the likelihood of false alarms W lt);
E w - the energy of the noise acting during the reception.
Where P and - and pulse power;
and , - pulse duration.
Where d ar - horizontal size of antenna mirror;
d aw - vertical dimension of antenna mirror.
k p = k p.t. ,
where k r.t. - theoretical coefficient of distinguishability.
k w.t. =,
where q 0 - detection parameter;
N - the number of impulses received from the target.
where W lt - the probability of a false alarm;
W by - probability of correct detection.
where t reg,
F and - pulse frequency;
Q a0.5 - the width of the antenna directional pattern at the level of 0.5 in power
where is the angular velocity of the antenna rotation.
where T survey is the survey period.
where k = 1.38 10 -23 J / deg is the Boltzmann constant;
k w - receiver noise figure;
T is the temperature of the receiver in degrees Kelvin ( T = 300K).
The maximum range of the radar, taking into account the absorption of radio wave energy.
where donkey - attenuation coefficient;
D - the width of the weakening layer.
Radar minimum range
If the antenna system does not impose restrictions, then the minimum range of the radar is determined by the pulse duration and the recovery time of the antenna switch.
where c is the speed of propagation of an electromagnetic wave in vacuum, c = 3 ∙ 10 8 ;
and , - pulse duration;
τ in - the recovery time of the antenna switch.
Radar range resolution
The real range resolution when using a circular view indicator as an output device is determined by the formula
(D) = (D) pot + (D) ind,
r de (d) sweat - potential range resolution;
(D) ind - the resolution of the indicator in terms of range.
For a signal in the form of an incoherent pack of rectangular pulses:
where c is the speed of propagation of an electromagnetic wave in a vacuum; c = 3 ∙ 10 8 ;
and , - pulse duration;
(D) ind - the range resolution of the indicator is calculated by the formula
r de d shk - the limiting value of the range scale;
k e = 0.4 - screen utilization factor,
Q f - the quality of the focusing of the tube.
Radar azimuth resolution
The real azimuth resolution is determined by the formula:
( az) = ( az) pot + ( az) ind,
where ( az) sweat - potential azimuth resolution when approximating the radiation pattern with a Gaussian curve;
( az) ind - the resolution of the indicator in azimuth
( az) pot = 1.3 Q a 0.5,
( az) ind = d n M f,
where d n - spot diameter of the cathode-ray tube;
M f - the scale of the scale.
where r - remove the mark from the center of the screen.
Accuracy of determination of coordinates by range and
The accuracy of determining the range depends on the accuracy of measuring the delay of the reflected signal, errors due to non-optimal signal processing, the presence of unaccounted signal delays in the transmission, reception and indication paths, and random errors in measuring the range in indicator devices.
Accuracy is characterized by measurement error. The resulting root mean square error of ranging is determined by the formula:
where (D) sweat - potential error in ranging.
(D) spread - error due to non-linearity of propagation;
(D) app - hardware error.
where q 0 - doubled signal-to-noise ratio.
Accuracy of determination of coordinates in azimuth
Systematic errors in the azimuth measurement can occur when the radar antenna system is inaccurately oriented and due to a discrepancy between the antenna position and the electrical azimuth scale.
Random errors in measuring the azimuth of the target are caused by the instability of the antenna rotation system, the instability of the azimuth mark formation schemes, as well as reading errors.
The resulting root mean square error of azimuth measurement is determined by:
Initial data (option 5)
- Wavelength , [cm] …............................................. ........................... .... 6
- Pulse power P and , [kW] .............................................. .............. 600
- Pulse duration and , [μs] .............................................. ........... 2,2
- Pulse frequency F and , [Hz] .............................................. ...... 700
- Horizontal dimension of antenna mirror d ar [m] ................................ 7
- Antenna mirror vertical dimension d aw , [m] ................................... 2,5
- Review period T review , [With] .............................................. .............................. 25
- Receiver noise figure k w ................................................. ....... 5
- Correct detection probability W by ............................. .......... 0,8
- False alarm probability W lt .. ................................................ ....... 10 -5
- Around View Indicator Screen Diameter d e , [mm] .................... 400
- Effective reflective target area S efo, [m 2 ] …...................... 30
- Focus quality Q f ............................................................... ...... 400
- Range scale limit D shk1 , [km] ........................... 50 D shk2 , [km] .......................... 400
- Measuring marks of range D , [km] ......................................... 15
- Measuring azimuth marks , [city] ........................................... 4
2. Calculation of tactical indicators of radar circular review
2.1 Calculation of the maximum range taking into account absorption
First, the maximum range of the radar is calculated without taking into account the attenuation of the energy of radio waves during propagation. The calculation is carried out according to the formula:
(1)
Let's calculate and set the values included in this expression:
E rad = P and u = 600 10 3 2.2 10 -6 = 1.32 [J]
S a = d ag d av = 7 2.5 = 8.75 [m 2]
k p = k p.t.
k w.t. =
101,2
0.51 [deg]
14.4 [deg / s]
Substituting the obtained values, we will have:
t region = 0.036 [s], N = 25 pulses and k r.t. = 2, 02.
Let = 10, then k P = 20.
E w - energy of noise acting during reception:
E w = kk w T = 1.38 10 -23 5 300 = 2.07 10 -20 [J]
Substituting all the obtained values in (1), we find 634.38 [km]
Now let's determine the maximum range of the radar, taking into account the absorption of radio wave energy:
(2)
Meaning donkey we find by charts. For = 6 cm donkey we take it equal to 0.01 dB / km. Suppose attenuation occurs over the entire range. Under this condition, formula (2) takes the form of the transcendental equation
(3)
Equation (3) is solved by the graphical analytical method. For don = 0.01 dB / km and D max = 634.38 km we calculate D max. Link = 305.9 km.
Conclusion: It can be seen from the calculations that the maximum range of the radar, taking into account the attenuation of the energy of radio waves during propagation, is equal to D max. L = 305.9 [km].
2.2 Calculation of real resolution in range and azimuth
The real range resolution when using a circular view indicator as an output device is determined by the formula:
(D) = (D) pot + (D) ind
For a signal in the form of an incoherent pack of rectangular pulses
0.33 [km]
for D shk1 = 50 [km], (D) ind1 = 0.31 [km]
for D shk2 = 400 [km], (D) ind2 = 2.50 [km]
Real range resolution:
for D shk1 = 50 km (D) 1 = (D) sweat + (D) ind1 = 0.33 + 0.31 = 0.64 [km]
for D shk2 = 400 km (D) 2 = (D) sweat + (D) ind2 = 0.33 + 2.50 = 2.83 [km]
The real azimuth resolution is calculated by the formula:
( az) = ( az) pot + ( az) ind
( az) pot = 1.3 Q a 0.5 = 0.663 [deg]
( az) ind = d n M f
Taking r = k e d e / 2 (mark at the edge of the screen), we get
0.717 [deg]
( az) = 0.663 + 0.717 = 1.38 [deg]
Conclusion: The real range resolution is equal to:
for D shk1 = 0.64 [km], for D shk2 = 2.83 [km].
Real azimuth resolution:
( az) = 1.38 [deg].
2.3 Calculation of the real accuracy of measuring the range and azimuth
Accuracy is characterized by measurement error. The resulting root mean square error of range measurement is calculated by the formula:
40,86
(D) sweat = [km]
Error due to non-straightness of propagation (D) spread neglected. Hardware errors (D) app are reduced to reading errors on the indicator scale (D) ind ... We accept the method of counting by electronic marks (scale rings) on the screen of the circular view indicator.
(D) ind = 0.1 D = 1.5 [km], where D - scale division value.
(D) = = 5 [km]
The resulting root-mean-square error of azimuth measurement is determined in the same way:
0,065
( az) ind = 0.1 = 0.4
Conclusion: Calculating the resulting root mean square error of the range measurement, we obtain (D) ( az) = 0.4 [deg].
Conclusion
In this course work, the parameters of a pulsed active radar were calculated (maximum range taking into account absorption, real resolution in range and azimuth, accuracy in measuring range and azimuth) for detecting air targets for air traffic control.
During the calculations, the following data were obtained:
1. The maximum range of the radar, taking into account the attenuation of the energy of radio waves during propagation, is D max.sl = 305.9 [km];
2. The real range resolution is equal to:
for D shk1 = 0.64 [km];
for D shk2 = 2.83 [km].
Real azimuth resolution: ( az) = 1.38 [deg].
3. The resulting root-mean-square error of measuring the range is (D) = 1.5 [km]. Mean square error of azimuth measurement ( az) = 0.4 [deg].
The advantages of pulsed radars include the simplicity of measuring the distances to targets and their range resolution, especially in the presence of many targets in the viewing area, as well as the almost complete temporal isolation between the received and emitted oscillations. The latter circumstance allows one and the same antenna to be used for both transmission and reception.
The disadvantage of pulsed radars is the need to use a high peak power of the radiated oscillations, as well as the impossibility of measuring short ranges - a large dead zone.
Radars are used to solve a wide range of tasks: from ensuring a soft landing of spacecraft on the surface of planets to measuring the speed of a person's movement, from controlling weapons in anti-missile and anti-aircraft defense systems to personal protection.
Bibliography
- Vasin V.V. Operating range of radio engineering measuring systems. Methodical development. - M.: MIEM 1977.
- Vasin V.V. Resolution and accuracy of measurements in radio engineering measuring systems. Methodical development. - M .: MIEM 1977.
- Vasin V.V. Methods for measuring coordinates and radial velocity of objects in radio engineering measuring systems. Lecture notes. - M .: MIEM 1975.
4. Bakulev P.A. Radar systems. Textbook for universities. - M .: "Radio
Technique "2004.
5. Radio engineering systems: Textbook for universities / Yu. M. Kazarinov [and others]; Ed. Yu.M. Kazarinova. - M .: Academy, 2008 .-- 590 p .:
Other similar works that may interest you. Wshm> |
|||
| 1029. | Development of software for the laboratory complex of the computer training system (KOS) "Expert Systems" | 4.25 MB | |
| The field of AI has more than forty years of development history. From the very beginning, it considered a number of very complex problems, which, along with others, are still the subject of research: automatic theorem proving ... | |||
| 3242. | Development of a system for digital correction of the dynamic characteristics of the primary transducer of the measuring system | 306.75 KB | |
| Time domain signal processing is widely used in modern electronic oscillography and digital oscilloscopes. And digital spectrum analyzers are used to represent signals in the private domain. Extension packages are used to study the mathematical aspects of signal processing | |||
| 13757. | Creation of a network testing system for electronic course support Operating systems (on the example of the Joomla tool shell) | 1.83 MB | |
| The program for writing tests will allow you to work with questions in electronic form, use all types of digital information to display the content of the question. The aim of the course work is to create a modern model of a web service for testing knowledge using web development tools and software implementation for the effective operation of the test system - protection from copying information and cheating when controlling knowledge, etc. The last two mean creating equal conditions for all passing knowledge control, the impossibility of cheating and .. ... | |||
| 523. | Functional systems of the body. The work of the nervous system | 4.53 KB | |
| Functional systems of the body. The work of the nervous system In addition to analyzers, that is, sensory systems, other systems function in the body. These systems can be clearly defined morphologically, that is, have a clear structure. Such systems include, for example, the respiratory or digestive system. | |||
| 6243. | 44.47 KB | ||
| CSRP class systems Customer Synchronized Resource Plnning. CRM systems Customer Reltionships Mngement customer relationship management. EAM class systems. Despite the fact that leading enterprises to strengthen the market are introducing the most powerful systems of the ERP class, this is no longer enough to increase the company's income. | |||
| 3754. | Number systems | 21.73 KB | |
| Number is a basic concept in mathematics, which usually means either quantity, size, weight, and the like, or an ordinal number, sequencing, code, cipher, and the like. | |||
| 4228. | Social systems | 11.38 KB | |
| Parsons is a warehouse manager for a large warehouse system. The most important storage systems are the system of culture, the system of specialness, and the system of behavioral organism. Razmezhuvannya mіzh chotirma viokremlenimy pіdsystems diy can be carried out for their characteristic functions. So, the system could be built to last before adapting the integration and preserving the eyes so that you can be satisfied with your functional vimogs. | |||
| 9218. | AIRCRAFT COURSE SYSTEMS | 592.07 KB | |
| Complex method of determining the course. To determine the course of aircraft, the most numerous group of course instruments and systems based on various physical principles of operation was created. Therefore, when measuring the course, errors occur due to the rotation of the Earth and the movement of the aircraft relative to the Earth. To reduce errors in the course readings, the apparent departure of the gyrocompass and the horizontal position of the gyroscope rotor axis are corrected. | |||
| 5055. | Political systems | 38.09 KB | |
| Functions of modernization of political systems. Considering politics as a sphere of interaction between a person and the state, we can distinguish two options for building these ties that are constantly but by no means evenly spread in the history of political life. | |||
| 8063. | Multibase systems | 7.39 KB | |
| Multi-base systems allow end users of different sites to access and share data without the need to physically integrate existing databases. They provide users with the ability to manage the databases of their own nodes without the centralized control that is common with conventional types of distributed DBMS. A local database administrator can grant access to a specific portion of their database by creating an export schema. | |||
Modern war is swift and fleeting. Often, the winner in a combat clash is the one who is the first to be able to detect a potential threat and adequately respond to it. For more than seventy years, the method of radar based on the emission of radio waves and registration of their reflections from various objects has been used to search for the enemy on land, sea and in the air. Devices that send and receive such signals are called radars or radars.
The term "radar" is an English abbreviation (radio detection and ranging), which was launched in 1941, but long ago became an independent word and entered most of the world's languages.
The invention of the radar is definitely a landmark event. It is difficult to imagine the modern world without radar stations. They are used in aviation, in sea transportation, with the help of radar, the weather is predicted, violators of traffic rules are identified, and the earth's surface is scanned. Radar complexes (RLC) have found their application in the space industry and in navigation systems.
However, the most widespread use of radars is found 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 outbreak of World War II. All 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 has decided the outcome of several landmark battles both in Europe and in the Pacific theater of operations.
Today, radars are used for an extremely wide range of military tasks, from tracking ICBM launches to artillery reconnaissance. Each plane, helicopter, and warship has its own radar system. Radars are the backbone of an air defense system. The newest radar complex with a phased antenna array will be installed on the promising Russian Armata tank. In general, the variety of modern radars is amazing. These are completely different devices that differ in size, characteristics and purpose.
We can say 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 radar operation, as well as about the history of radar systems.
How radar works
A 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, which are emitted and received by a device called a radar or radar.
The physical principle of operation of a 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. By analyzing them, the radar is able to detect an object at a certain point in space, and also show its main characteristics: speed, height, size. Any radar is a complex radio-technical device, consisting of many components.
Any radar consists of three main elements: a signal transmitter, an antenna and a receiver. All radar stations can be divided into two large groups:
- impulse;
- continuous action.
A 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 comes back and hits the receiver. Pulse repetition rate 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 is turned off for a while and the receiver is turned on. After receiving it, the opposite process takes place.
Pulse radars have both disadvantages and advantages. They can determine the range of several targets at once, such a radar may well manage with one antenna, the indicators of such devices are simple. However, in this case, the signal emitted by such a radar must have a fairly high power. You can also add that all modern tracking radars are made according to a pulse scheme.
Pulsed radar stations usually use magnetrons or traveling wave tubes as a signal source.
The radar antenna focuses and directs the electromagnetic signal, picks up the reflected pulse and transmits it to the receiver. There are radars in which the signal is received and transmitted 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 work in a specific sector. The radar beam can be directed in a spiral or in the form of a cone. If necessary, the radar can track a moving target, constantly pointing an antenna at it using special systems.
The functions of the receiver include processing the received information and transmitting it to the screen from which it is read by the operator.
In addition to pulse radars, there are continuous radars that constantly emit electromagnetic waves. Such radar stations use the Doppler effect in their work. It consists in the fact that the frequency of an electromagnetic wave reflected from an object that approaches the signal source will be higher than that from a receding object. In this case, the frequency of the emitted pulse remains unchanged. Radars of this type do not detect stationary objects, their receiver picks up only waves with a frequency higher or lower than the emitted one.
Typical Doppler radar is the radar used by traffic police officers to determine the speed of vehicles.
The main problem of continuous radars is the impossibility with their help 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 continuous-wave radar stations have the ability to determine the distance to an object. This is done by changing the frequency of the radar during operation.
One of the main problems in the operation of pulsed radars is interference from stationary objects - as a rule, it is the earth's surface, mountains, hills. When airborne impulse radars of aircraft are operating, all objects located below are "shaded" by a signal reflected from the earth's surface. If we talk about ground 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 also so-called secondary radars, which 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 it is irradiated with an electromagnetic signal, the transponder provides additional information about the height, route, board number, and its nationality.
Also, radar stations can be divided according to the length and frequency of the wave at which they operate. For example, to study the Earth's surface, as well as to work at significant 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, radar with a wavelength of 7.5-15 cm is used, and over-the-horizon radars of missile launch detection stations operate on waves with a length of 10 to 100 meters.
Radar history
The idea of radar arose almost immediately after the discovery of radio waves. In 1905, Christian Hülsmeier, 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 poor visibility conditions. However, the shipping companies were not interested in the new device.
Experiments with radar were also carried out in Russia. Back in the late 19th century, the Russian scientist Popov discovered that metal objects impede the propagation of radio waves.
In the early 1920s, American engineers Albert Taylor and Leo Young were able to detect a passing ship using radio waves. However, the state of the radio engineering industry at that time was such that it was difficult to create industrial designs of radar stations.
The first radar stations that could be used for solving practical problems appeared in England around the mid-30s. These devices were very large and could only be installed on land or on the decks of large ships. It was only in 1937 that a prototype of a miniature radar was created that could be installed on an aircraft. By the start of World War II, the British had a deployed chain of radar stations called the Chain Home.
We were engaged in a new promising direction in Germany. And, I must say, not without success. Already in 1935, Raeder, the commander-in-chief of the German fleet, was shown a working radar with an electron-beam display. Later, on its basis, serial samples of radars were created: 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 radars later than the British. Hitler and the top of the Reich considered radars to be exclusively defensive weapons, which were not too needed by the victorious German army. It is for this reason that by the beginning of the Battle of Britain, the Germans had deployed only eight Freya radars, although in terms of their characteristics they were at least as good as their British counterparts. In general, we can say that it was the successful use of radars 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, the allies were able to unravel the secrets of the work of German radars, 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 were able to overtake them and approach the beginning of World War II with the most advanced radar aircraft detection system.
Already in September 1935, the British began building a network of radar stations, which had already included twenty radars before the war. She 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 for onboard radar stations installed on American and British aircraft.
Work in the field of military radar was carried out in the Soviet Union as well. The first successful experiments to detect aircraft using radar stations in the USSR were carried out in the mid-1930s. In 1939, the first radar RUS-1 was adopted by the Red Army, and in 1940 - RUS-2. Both of these stations were put into serial production.
The Second World War clearly demonstrated 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 received 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 has become 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 thousand km). It was quite simple: Kabanov found out that radio waves 10-100 meters long can be reflected from the ionosphere, and irradiating targets on the earth's surface, return the same way to the radar.
Later, based on this idea, radars for over-the-horizon detection of the launch of ballistic missiles were developed. An example of such a radar 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 directions in 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, the work of which is controlled by a powerful computer. Radio waves emitted by different sources in a phased array can amplify each other if they are in phase, or, conversely, weaken.
The radar signal with a phased array can be given any desired shape, it can be moved in space without changing the position of the antenna itself, and it can 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 drawbacks: cooling the radar with phased array is a big problem, in addition, they are difficult to manufacture and are expensive.
New phased array radars are being installed on fifth-generation fighters. This technology is used in the US missile early warning system. A radar complex with a phased array 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 phased array radars.
If you have any questions - leave them in the comments below the article. We or our visitors will be happy to answer them.
The principle of operation of a pulsed radar can be understood by considering the "Simplified block diagram of a pulsed radar (Fig. 3.1, slide 20, 25 ) and graphs explaining the operation of a pulsed radar (Fig.3.2, slide 21, 26 ).
It is best to begin to consider the operation of a pulsed radar from the synchronization unit (launch unit) of the station. This block sets the "rhythm" of the station's work: it sets the repetition rate of the probing signals, synchronizes the operation of the indicator device with the operation of the station transmitter. The synchronizer generates short-term sharp-pointed pulses AND zap with a certain repetition rate T P... Structurally, the synchronizer can be made in the form of a separate unit or represent a single whole with the station modulator.
Modulator controls the operation of the microwave generator, turns it on and off. The modulator is triggered by synchronizer pulses and generates powerful rectangular pulses of the required amplitude U m and duration τ and... The microwave generator is switched on only in the presence of modulator pulses. The frequency of switching on the microwave generator, and, consequently, the repetition rate of the probing pulses is determined by the frequency of the synchronizer pulses T P... The duration of the microwave generator each time it is turned on (that is, the duration of the probe pulse) depends on the duration of the pulse shaping in the modulator τ and... Modulator pulse duration τ and usually is a few microseconds, and the pauses between them are hundreds and thousands of microseconds.
Under the action of the modulator voltage, the microwave generator generates powerful radio pulses U gene, the duration and shape of which is determined by the duration and shape of the modulator pulses. High-frequency oscillations, that is, probing pulses from the microwave generator, go through the antenna switch to the antenna. The frequency of oscillation of radio pulses is determined by the parameters of the microwave generator.
Antenna switch (AP) provides the ability to operate the transmitter and receiver on one common antenna. During the generation of the probe pulse (μs), it connects the antenna to the transmitter output and blocks the receiver input, and for the rest of the time (the pause time is hundreds, thousands of μs), it connects the antenna to the receiver input and disconnects it from the transmitter. In a pulse radar, automatic high-speed switches are used as antenna switches.
The antenna converts microwave oscillations into electromagnetic energy (radio waves) and focuses it into a narrow beam. Signals reflected from the target are received by the antenna, pass through the antenna switch and enter the receiver input U With, where they are selected, amplified, detected and fed through the anti-interference equipment to the indicating devices.
The anti-jamming equipment is switched on only if there is passive and active interference in the radar coverage area. This equipment will be studied in detail in topic 7.
The display device is a terminal device of the radar and serves to display and retrieve radar information. The electrical circuit and design of the indicating devices are determined by the practical purpose of the station and can be very different. for instance, for radar detection using indicator devices, the air situation should be reproduced and the coordinates of targets D and β should be determined. These indicators are called all-round view indicators (PIDs). Altitude indicators are used in the target altitude measurement radar (altimeters). Range indicators measure only the range to the target and are used for control.
To accurately determine the range, it is necessary to measure the time interval t s(tens and hundreds of microseconds) with high accuracy, that is, devices with very low inertia are required. Therefore, in range indicators, cathode-ray tubes (CRT) are used as measuring instruments.
Note. The principle of measuring the range was studied in lesson 1, therefore, when studying this issue, the main attention should be paid to the formation of the sweep on the PPI.
The essence of ranging (lag time t s) with the help of a CRT can be explained by the example of using a linear sweep in a tube with an electrostatic electron beam.
With a linear scan in a CRT, an electron beam under the influence of a scan voltage U R periodically moves at a constant speed in a straight line from left to right (Fig. 1.7, slide 9, 12 ). The sweep voltage is generated by a special sweep generator, which is triggered by the same synchronizer pulse as the transmitter modulator. Therefore, the movement of the beam across the screen starts every time the probe pulse is sent.
When using the amplitude mark of the target, the reflected signal coming from the output of the receiver causes the beam to be deflected in the perpendicular direction. Thus, the reflected signal can be seen on the screen of the tube. The further the target is, the more time passes before the appearance of the reflected pulse and further to the right the beam manages to move along the sweep line. Obviously, each point of the scan line corresponds to a certain moment of arrival of the reflected signal and, therefore, a certain value of the range.
In the radar operating in the circular view mode, circular view indicators (IKO) and CRT with electromagnetic beam deflection and brightness mark are used. The radar antenna with a narrow beam (BP) is moved by the antenna rotation mechanism in the horizontal plane and "scans" the surrounding space (Fig. 3.3, slide,
On the PPI, the range sweep line rotates in azimuth synchronously with the antenna, and the beginning of the movement of the electron beam from the center of the tube in the radial direction coincides with the instant of emission of the probe pulse. Synchronous rotation of the sweep on the IKO with the radar antenna is carried out using a power synchronous drive (SSP). The response signals are displayed on the indicator screen in the form of a brightness mark.
ICO allows you to simultaneously determine the range D and azimuth β goals. For the convenience of reading on the screen of the PPI, scale marks of range are electronically applied in the form of circles and scale marks of azimuth in the form of bright radial lines (Fig. 3.3, slide, 8, 27 ).
Note. Using the TV set and the TV card, invite the students to determine the coordinates of the goals. Indicate the scale of the indicator: range marks follow after 10 km, azimuth marks - after 10 degrees.
CONCLUSION
(slide 28)
Determining the distance to an object with the impulse method is reduced to measuring the delay time t s the reflected signal relative to the probe pulse. The moment of emission of the probe pulse is taken as the origin of the time of propagation of radio waves.
Advantages of pulse radars:
convenience of visual observation of all targets simultaneously irradiated by the antenna in the form of marks on the indicator screen;
alternating operation of the transmitter and receiver allows you to use one common antenna for transmission and reception.
Second training question.
The main indicators of the impulse method
The main indicators of the impulse method are (slide 29) :
Unambiguously determined maximum range, D;
range resolution, δД;
minimum detectable range, D min .
Let's consider these indicators.
Unambiguous maximum range
The maximum range of the radar is determined by the basic radar formula and depends on the radar parameters.
The unambiguity of determining the distance to the object depends on the repetition period of the probing pulses T P... Further, this question is stated as follows.
The maximum range of the radar is 300 km. Determine the delay time to the target located at this range
The repetition period of the probing pulses was chosen equal to 1000 μs. Determine the range to the target, the delay time to which is T P
There are two targets in the airspace: target no. 1 at a range of 100 km and target no. 2 at a range of 200 km. How will the marks from these targets look like on the radar indicator (Fig. 3.4, slide 22, 30 ).
When probing space with pulses with a repetition period of 1000 μs, the mark from target No. 1 will be displayed at a distance of 50 km, since after a range of 150 km a new sweep period will begin and the distant target will mark at the beginning of the scale (at a distance of 50 km). The counted range does not correspond to the real one.
How to eliminate ambiguity in determining the range?
After summarizing the students' answers, conclude:
For an unambiguous determination of the range, it is necessary to select the repetition period of the probing pulses in accordance with the specified maximum range of the radar, that is
For a given range of 300 km, the repetition period of the sounding pulses must be greater than 2000 μs or the repetition frequency must be less than 500 Hz.
In addition, the maximum detectable range depends on the width of the antenna beam, the rotation speed of the antenna and the required number of pulses reflected from the target in one rotation of the antenna.
Range resolution (δD) is the minimum distance between two targets located at the same azimuth and elevation, at which the signals reflected from them are observed on the indicator screen separately.(Fig.3.5, slide 23, 31, 32 ).
For a given duration of the probing pulse τ and and distance between targets ∆Д 1 targets # 1 and # 2 are irradiated separately. With the same pulse width, but with a distance between targets ∆Д 2 targets no. 3 and no. 4 are irradiated simultaneously. Therefore, in the first case, the PPIs will be visible on the screen separately, and in the second - together. From this it follows that for the separate reception of pulse signals, it is necessary that the time interval between the moments of their reception be greater than the pulse duration τ and (∆ t > τ and )
Minimum difference (D 2 - D 1 ), at which targets are visible on the screen separately, by definition there is a range resolution δД, hence
In addition to the pulse duration τ and the resolution of the station in terms of range is influenced by the resolution of the indicator, which is determined by the sweep scale and the minimum diameter of the glowing spot on the CRT screen ( d P ≈ 1 mm). The larger the range sweep scale and the better the focusing of the CRT beam, the better the resolution of the indicator.
In the general case, the range resolution of the radar is
where δД and- the resolution of the indicator.
The less δД , the better the resolution. Typically, the radar range resolution is δД= (0.5 ... 5) km.
In contrast to the resolution in terms of range, the resolution in angular coordinates (in azimuth δβ and the corner of the place δε ) not depends from the radar method and is determined by the width of the antenna radiation pattern in the corresponding plane, which is usually measured at the half power level.
Radar azimuth resolution δβ O is equal to:
δβ O = φ 0.5r O + δβ and O ,
where φ 0.5r O- width of the directional pattern at half power in the horizontal plane;
δβ and O- azimuth resolution of the indicator equipment.
High-resolution radar stations allow you to separately observe and determine the coordinates of closely spaced targets.
The minimum detectable range is the shortest distance at which the station can still detect a target. Sometimes the area around the station, in which targets are not detected, is called a "dead" zone. ( slide 33 ).
The use of one antenna in a pulsed radar for transmitting sounding pulses and receiving reflected signals requires turning off the receiver for the duration of the radiation of the sounding pulse. τ u... Therefore, the reflected signals arriving at the station at the moment when its receiver is not connected to the antenna will not be received and registered on the indicators. The length of time during which the receiver cannot receive reflected signals is determined by the duration of the probe pulse τ u and the time required to switch the antenna from transmitting to receiving after exposure to a probe pulse of the transmitter t v .
Knowing this time, the value of the minimum range D min pulse radar can be determined by the formula
where τ u- the duration of the radar probe pulse;
t v- time of switching on the receiver after the end of the probe pulse of the transmitter (units - μs).
for instance... At τ u= 10μs D min = 1500 m
at τ u= 1 μs D min = 150 m.
It should be borne in mind that to increase the radius of the "dead" zone D min leads to the presence on the screen of the indicator reflected from local objects and the limited range of rotation of the antenna in elevation.
CONCLUSION
The pulsed radar method is effective for measuring the range of objects located at great distances.
Third study question
Continuous radiation method
Along with the use of the pulsed method, radar can be carried out using installations with continuous radiation of energy. With the continuous method of radiation, it is possible to send a lot of energy towards the target.
Along with the advantage of the energy order, the method of continuous radiation is inferior to the pulsed method in a number of indicators. Depending on which parameter of the reflected signal serves as the basis for measuring the range to the target, with the continuous method of radar, they are distinguished:
phase (phasometric) method of radar;
frequency method of radar.
Combined methods of radar are also possible, in particular, pulse-phase and pulse-frequency.
With the phase method For radar, the distance from the target to the target is judged by the phase difference between the emitted and received reflected vibrations. The first phasometric distance measurement methods were proposed and developed by academicians L.I. Mandelstam and N.D. Papaleksi. These methods have found application in long-wave long-range aviation radio navigation systems.
With the frequency method For radar, the distance to the target is judged by the beat frequency between the direct and reflected signals.
Note. Students study these methods independently. Literature: Slutsky V.Z. Pulse technique and fundamentals of radar. S. 227-236.
CONCLUSION
Determination of the distance to the object with the pulse method is reduced to changing the delay time t zap of the reflected signal relative to the probing pulse.
For unambiguous determination of the distance to the object, it is necessary that t zap.mah ≤ T p.
The distance resolution δД is the better, the shorter the duration of the probe pulse τ u.
The article discusses the principle of operation and the general structural diagram of the ship's radar. The operation of radar stations (radar) is based on the use of the phenomenon of reflection of radio waves from various obstacles located in the path of their propagation, that is, in radar, the phenomenon of echo is used to determine the position of objects. For this, the radar has a transmitter, a receiver, a special antenna-waveguide device and an indicator with a screen for visual observation of echo signals. Thus, the operation of a radar station can be represented as follows: a radar transmitter generates high-frequency oscillations of a certain shape, which are sent into space by a narrow beam that continuously rotates along the horizon. Reflected vibrations from any object in the form of an echo are received by the receiver and displayed on the indicator screen, while it is possible to immediately determine on the screen the direction (bearing) to the object and its distance from the vessel.
The bearing to an object is determined by the direction of a narrow radar beam, which is currently falling on the object and reflected from it.
The distance to the object can be obtained by measuring small time intervals between the sending of the probe pulse and the moment of receiving the reflected pulse, provided that the radio pulses propagate at a speed of c = 3 X 108 m / s. The ship's radars have all-round visibility indicators (IKO), on the screen of which an image of the navigation situation surrounding the ship is formed.
Coastal radars installed in ports, on approaches to them and on canals or on complex fairways are widespread. With their help, it became possible to carry out the entry of ships into the port, to control the movement of ships along the fairway, canal in conditions of poor visibility, as a result of which the idle time of ships is significantly reduced. These stations in some ports are supplemented with special television transmitting equipment, which transmits images from the radar station screen to ships approaching the port. The transmitted images are received on the ship by a conventional television receiver, which greatly facilitates the navigator's task of entering the ship into the port in poor visibility.
Coastal (port) radars can also be used by the port dispatcher to monitor the movement of ships located in the port water area or on the approaches to it.
Let's consider the principle of operation of a ship's radar with a circular view indicator. Let's use a simplified block diagram of the radar to explain its operation (Fig. 1).
The triggering pulse generated by the ZI generator initiates (synchronizes) all radar units.
When the trigger pulses arrive at the transmitter, the modulator (Mod) generates a rectangular pulse with a duration of several tenths of a microsecond, which is fed to the magnetron generator (MG).
The magnetron generates a probing pulse with a power of 70-80 kW, wavelength 1 = 3.2 cm, frequency / s = 9400 MHz. The impulse of the magnetron through the antenna switch (AP) through a special waveguide is supplied to the antenna and is emitted into space by a narrow directional beam. The beam width is 1-2 ° in the horizontal plane, and about 20 ° in the vertical plane. The antenna, rotating around the vertical axis at a speed of 12-30 rpm, irradiates the entire space surrounding the vessel.
The reflected signals are received by the same antenna, therefore, the AP makes alternate connection of the antenna to the transmitter, then to the receiver. The reflected pulse is fed through the antenna switch to the mixer, to which the klystron generator (KG) is connected. The latter generates low-power oscillations with a frequency f Г = 946 0 MHz.
In the mixer, as a result of the addition of oscillations, an intermediate frequency is allocated fPR = fG-fC = 60 MHz, which is then fed to an intermediate frequency amplifier (IFA), it amplifies the reflected pulses. With the help of a detector at the output of the IF amplifier, the amplified pulses are converted into video pulses, which are fed to the video amplifier through the video mixer (VS). Here they are amplified and fed to the cathode of the cathode-ray tube (ICO).
The cathode ray tube is a specially designed vacuum electron tube (see Fig. 1).
It consists of three main parts: an electron gun with a focusing device, a deflecting magnetic system, and a glass bulb with an afterglow screen.
The electron gun 1-2 and the focusing device 4 form a dense, well-focused electron beam, and the deflecting system 5 serves to control this electron beam.
After passing through the deflecting system, the electron beam hits the screen 8, which is covered with a special substance that has the ability to glow when bombarded with electrons. The inner side of the wide part of the tube is covered with a special conductive layer (graphite). This layer is the main anode of the tube 7 and has a contact to which a high positive voltage is applied. Anode 3 is an accelerating electrode.
The brightness of the glowing point on the CRT screen is regulated by changing the negative voltage on the control electrode 2 using the "Brightness" potentiometer. In the normal state, the tube is locked with a negative voltage at gate 2.
An image of the surroundings on the screen of the circular view indicator is obtained as follows.
Simultaneously with the beginning of the emission, the transmitter of the probe pulse starts the sweep generator, which consists of a multivibrator (MB) and a sawtooth current generator (SSG), which generates sawtooth pulses. These pulses are fed to the deflection system 5, which has a rotation mechanism that is connected to the receiving selsyn 6.
At the same time, a rectangular positive voltage pulse is applied to control electrode 2 and unlocks it. With the appearance of an increasing (sawtooth) current in the CRT deflecting system, the electron beam begins to smoothly deviate from the center to the edge of the tube and a luminous sweep radius appears on the screen. The radial movement of the beam across the screen is very weak. At the moment of arrival of the reflected signal, the potential between the grid and the control cathode increases, the tube is unlocked, and a point corresponding to the current position of the beam making a radial movement starts to glow on the screen. The distance from the center of the screen to the luminous point will be proportional to the distance to the object. The deflection system has a rotary motion.
The mechanism of rotation of the deflecting system is connected by synchronous transmission with the selsyn-sensor of the antenna 9, therefore the deflecting coil rotates around the CRT neck synchronously and in phase with the antenna 12. As a result, a rotating sweep radius appears on the CRT screen.
When the antenna is turned, the sweep line is rotated and new areas begin to glow on the indicator screen, corresponding to pulses reflected from various objects located at different bearings. For a complete rotation of the antenna, the entire surface of the CRT screen is covered with a multitude of radial scan lines, which are illuminated only if there are reflective objects on the corresponding bearings. Thus, a complete picture of the environment surrounding the ship is reproduced on the screen of the tube.
For approximate measurement of distances to various objects on the CRT screen, scale rings (stationary range circles) are applied by means of electronic illumination generated in the PKD unit. For a more accurate measurement of the distance in the radar, a special ranging device is used, with a so-called moving range circle (PKD).
To measure the distance to any target on the CRT screen, it is necessary, by rotating the rangefinder knob, to align the PCD with the target mark and take a reading in miles and tenths from a counter mechanically connected to the rangefinder handle.
In addition to echoes and distance rings, heading mark 10 is illuminated on the CRT screen (see Fig. 1). This is achieved by applying a positive pulse to the control grid of the CRT at the moment when the maximum radiation of the antenna passes the direction coinciding with the center plane of the vessel.
The image on the CRT screen can be oriented relative to the ship's DP (stabilization along the course) or relative to the true meridian (stabilization along the north). In the latter case, the deflecting system of the tube also has a synchronous connection with the gyrocompass.
The radar station consists of the following main elements:
Transmitting device;
Receiving device;
Antenna switch and antenna device;
Terminal device;
Synchronizer.
The block diagram of the radar is shown in Figure 5.2.
Fig.5.2 Block diagram of the radar station.
Transmitting device The radar is designed to generate a sounding signal and transmit it to the antenna.
Receiving device The radar is intended for preprocessing the reflected signal received by the antenna. It separates the useful signal from a mixture of signal and interference, converts the radio signal into a video signal and transfers it to the terminal device.
Antenna switch is designed to connect the transmitter to the antenna when the sounding signal is emitted and to connect the receiver to the antenna when the reflected signal is received.
Terminal device to analyze the useful signal. The type of terminal device depends on the type of signal (analog or digital), the recipient of the radar information (operator, automatic coordinate determination device, computer, etc.) and the type of radar information.
Synchronizer provides a predetermined sequence of operation of the radar elements. So, for example, in the most common radars with a pulse mode of operation, the synchronizer performs the following functions:
Coordination of the moment of formation of the probing pulse with the moment of starting the time base of the indicator or the zero count of the computing device;
Coordination of the position of the antenna directional pattern in space with the sweep of the indicator or the zero count of the computing device;
Determination of the moment of opening the receiver and the interval of its operation.
In this case, the following synchronization methods are in principle possible:
1. Synchronization from transmitter to terminal.
In such radars, the moment of formation of the probing pulse determines the moment of starting the time base of the indicator or the moment of zeroing of the computing device. The advantage of this synchronization method is that the instability of the repetition rate of the transmitter's probing pulses does not affect the accuracy of the radar measurements. However, such radars are inherently unstable in the launch of the terminal device, which is difficult to completely eliminate.
2. Synchronization from terminal to transmitter.
In this case, the operation of the terminal and transmitting device is controlled by a highly stable generator included in the terminal device. This achieves high accuracy of radar measurements. However, problems arise when changing the repetition rate of the probe pulses.
3. Synchronization using a separate highly stable crystal oscillator, not included in the transmitter or terminal device.
This method of synchronization is used in most modern radars, which usually provide for the possibility of changing the repetition rate of the sounding pulses during the operation of the station. This is necessary to ensure the immunity of the radar when operating in conditions of passive or active radar interference.
The structural diagram of the radar mainly depends on its purpose, the type of the sounding signal (pulse or continuous) and the modulated parameter of the radio signal.
However, in the general case, the procedure for processing a radio signal in a radar must be coordinated not only with the type of sounding signal, but also with the type of interference. Therefore, the structural diagram of the radar should take into account the sources of active and passive radio-electronic interference.
This task complicates the work of any radar, because interference causes distortion of the signal reflected from the target and leads to the loss of useful radar information. Therefore, in the process of processing the reflected signal, attempts are made to suppress interference, which is achieved by introducing electronic interference protection devices into the structure of the radar.
