Good evening everyone :) I was surfing the Internet after visiting a military unit with a considerable number of radar stations.
I was very interested in the radars themselves. I think it’s not just me, so I decided to post this article :)
Radar stations P-15 and P-19
The P-15 UHF radar is designed to detect low-flying targets. Entered service in 1955. It is used as part of radar posts of radio engineering formations, control batteries of anti-aircraft artillery and missile formations of the operational air defense level and at tactical level air defense control posts.
The P-15 station is mounted on one vehicle along with the antenna system and is deployed into a combat position in 10 minutes. The power supply unit is transported in a trailer.
The station has three operating modes:
- amplitude;
- amplitude with accumulation;
- coherent-pulse. 
The P-19 radar is designed to conduct reconnaissance of air targets at low and medium altitudes, detect targets, determine their current coordinates in azimuth and identification range, as well as transmit Radar information to command posts and associated systems. It is a mobile two-coordinate radar station located on two vehicles.
The first vehicle houses transmitting and receiving equipment, anti-jamming equipment, indicator equipment, equipment for transmitting radar information, simulating, communicating and interfacing with consumers of radar information, functional control and ground-based radar interrogator equipment.
The second vehicle houses the radar antenna-rotator device and power supply units.
Difficult climatic conditions and the duration of operation of the P-15 and P-19 radar stations have led to the fact that by now most of the radars require resource restoration.
The only way out of this situation is considered to be the modernization of the old radar fleet based on the Kasta-2E1 radar.
The modernization proposals took into account the following:
Maintaining the integrity of the main radar systems (antenna system, antenna rotation drive, microwave path, power supply system, vehicles);
Possibility of modernization under operating conditions with minimal financial costs;
Possibility of using released P-19 radar equipment to restore products that have not been upgraded.
As a result of modernization, the P-19 mobile solid-state low-altitude radar will be capable of performing airspace control tasks, determining the range and azimuth of airborne objects - airplanes, helicopters, remotely piloted aircraft and cruise missiles, including those operating at low and extremely low altitudes, at against a background of intense reflections from the underlying surface, local objects and hydrometeorological formations.
The radar is easily adaptable for use in various military and civil systems. It can be used for information support of air defense systems, air forces, coastal defense systems, rapid reaction forces, and traffic control systems for civil aviation aircraft. In addition to traditional use as a means of detecting low-flying targets in the interests of the armed forces, the modernized radar can be used to control airspace in order to suppress the transportation of weapons and drugs by low-altitude, low-speed and small-sized aircraft in the interests of special services and police units involved in the fight against drug trafficking and weapons smuggling .
Upgraded radar station P-18
Designed to detect aircraft, determine their current coordinates and issue target designations. It is one of the most popular and cheapest meter stations. The service life of these stations has been largely exhausted, and their replacement and repair are difficult due to the lack of currently outdated components.
To extend the service life of the P-18 radar and improve a number of tactical and technical characteristics, the station was modernized based on an installation kit that has a resource of at least 20-25 thousand hours and a service life of 12 years.
Four additional antennas were introduced into the antenna system for adaptive suppression of active interference, installed on two separate masts. The purpose of the modernization is to create a radar with performance characteristics that meet modern requirements, while maintaining the appearance of the base product due to:
- replacement of the outdated element base of the P-18 radar equipment with a modern one;
- replacement of a tube transmitting device with a solid state one;
- introduction of a signal processing system on digital processors;
- introduction of an adaptive suppression system for active noise interference;
- introduction of systems for secondary processing, monitoring and diagnostics of equipment, information display and control based on a universal computer;
- ensuring interface with modern automated control systems.
As a result of modernization:
- the volume of equipment has been reduced;
- increased reliability of the product;
- increased noise immunity;
- improved accuracy characteristics;
- improved performance characteristics.
The installation kit is built into the radar control cabin instead of the old equipment. The small dimensions of the installation kit allow upgrading of products on site.
Radar complex P-40A
Range finder 1RL128 “Armor”
The 1RL128 Bronya radar rangefinder is an all-round radar and, together with the 1RL132 radar altimeter, forms the P-40A three-dimensional radar complex.
Rangefinder 1RL128 is intended for:
- detection of air targets;
- determination of slant range and azimuth of air targets;
- automatic output of the altimeter antenna to the target and display of the target height value according to the altimeter data;
- determination of state ownership of targets (“friend or foe”);
- control your aircraft using the all-round visibility indicator and the R-862 aircraft radio;
- direction finding of active jammers.
The radar complex is part of radio engineering formations and air defense formations, as well as anti-aircraft missile (artillery) units and military air defense formations.
Structurally, the antenna-feeder system, all equipment and ground-based radar interrogator are placed on a 426U self-propelled tracked chassis with its components. In addition, it houses two gas turbine power units.
Two-dimensional standby radar "Sky-SV"
Designed for detection and identification of air targets in standby mode when operating as part of military air defense radar units, equipped and not equipped with automation equipment.
The radar is a mobile coherent pulse radar station located on four transport units (three cars and a trailer).
The first vehicle contains transmitting and receiving equipment, anti-interference equipment, indicator equipment, equipment for auto-recording and transmission of radar information, simulation, communication and documentation, interface with consumers of radar information, functional monitoring and continuous diagnostics, equipment for a ground-based radar interrogator (GRI).
The second vehicle is equipped with a radar rotating antenna device.
The third car has a diesel power plant.
An NRZ antenna-rotating device is placed on the trailer.
The radar can be equipped with two remote all-round indicators and interface cables.
Mobile three-coordinate radar station 9S18M1 “Dome”
Designed to provide radar information to command posts of anti-aircraft missile formations and military air defense units and control posts of air defense system facilities of motorized rifle and tank divisions equipped with the Buk-M1-2 and Tor-M1 air defense systems.
The 9S18M1 radar is a three-coordinate coherent-pulse detection and target designation station that uses long-duration probing pulses, which provides high energy emitted signals.
The radar is equipped with digital equipment for automatic and semi-automatic coordinate acquisition and equipment for identifying detected targets. The entire process of radar operation is as automated as possible thanks to the use of high-speed computing electronic means. To increase the efficiency of operation in conditions of active and passive interference, the radar uses modern methods and means of noise protection.
The 9S18M1 radar is located on a cross-country tracked chassis and is equipped with an autonomous power supply system, navigation, orientation and topographical equipment, telecode and voice radio communications. In addition, the radar has a built-in automated functional control system, which ensures quick detection of a faulty replacement element and a simulator for processing operator skills. To transfer them from the traveling position to the combat position and back, devices for automatic deployment and collapse of the station are used.
The radar can operate in harsh climatic conditions, move under its own power on roads and off-road, and can also be transported by any type of transport, including air.
Air Force Air Defense
Radar station "Oborona-14"
Designed for long-range detection and measurement of range and azimuth of air targets when operating as part of an automated control system or autonomously.
The radar is located on six transport units (two semi-trailers with equipment, two with an antenna-mast device and two trailers with a power supply system). A separate semi-trailer has a remote post with two indicators. It can be removed from the station at a distance of up to 1 km. To identify air targets, the radar is equipped with a ground-based radio interrogator.
The station uses a folding antenna system design, which significantly reduces its deployment time. Protection against active noise interference is provided by tuning the operating frequency and a three-channel auto-compensation system, which allows you to automatically form “zeros” in the antenna radiation pattern in the direction of the jammers. To protect against passive interference, coherent-compensation equipment on potential-scopic tubes is used.
The station provides three modes of viewing the space:
- “lower beam” - with an increased target detection range at low and medium altitudes;
- “upper beam” - with an increased upper limit of the detection zone in elevation;
Scans - with alternate (through review) inclusion of the upper and lower beams.
The station can be operated at an ambient temperature of ± 50 °C, wind speed up to 30 m/s. Many of these stations were exported and are still in use by the troops.
The Oborona-14 radar can be upgraded using a modern element base using solid-state transmitters and a digital information processing system. The developed installation kit of the equipment allows us to carry out work on modernizing the radar directly at the consumer's site in a short time, bringing its characteristics closer to the characteristics of modern radars, and extending the service life by 12 - 15 years at a cost several times lower than when purchasing a new station.
Radar station "Sky"
Designed to detect, identify, measure three coordinates and track air targets, including aircraft manufactured using stealth technology. It is used in air defense forces as part of an automated control system or independently.
The all-round radar "Sky" is located on eight transport units (on three semi-trailers - an antenna-mast device, on two - equipment, on three trailers - an autonomous power supply system). There is a remote device transported in containers.
The radar operates in the meter wavelength range and combines the functions of a range finder and altimeter. In this range of radio waves, the radar is slightly vulnerable to homing projectiles and anti-location missiles operating in other ranges, and in the operating range these weapons are currently absent. In the vertical plane, electronic scanning with an altimeter beam is implemented (without the use of phase shifters) in each range resolution element.
Noise immunity under conditions of active interference is ensured by adaptive adjustment of the operating frequency and a multi-channel auto-compensation system. The passive interference protection system is also built on the basis of correlation auto-compensators.
For the first time, to ensure noise immunity under conditions of exposure to combined interference, spatio-temporal decoupling of protection systems against active and passive interference has been implemented.
Measuring and issuing coordinates is carried out using auto-recording equipment based on a built-in special computer. There is an automated monitoring and diagnostic system.
The transmitting device is highly reliable, which is achieved through 100% redundancy of a powerful amplifier and the use of a group solid-state modulator.
The Nebo radar can be operated at ambient temperatures of ± 50 °C and wind speeds of up to 35 m/s.
Three-dimensional mobile surveillance radar 1L117M
Designed to monitor airspace and determine three coordinates (azimuth, slant range, altitude) of air targets. The radar is built on modern components, has high potential and low energy consumption. In addition, the radar has a built-in state identification interrogator and equipment for primary and secondary data processing, a set of remote indicator equipment, thanks to which it can be used in automated and non-automated air defense systems and the Air Force for flight control and interception guidance, as well as for air control traffic (ATC).
Radar 1L117M is an improved modification of the previous model 1L117.
The main difference of the improved radar is the use of a klystron output power amplifier of the transmitter, which made it possible to increase the stability of the emitted signals and, accordingly, the passive interference suppression coefficient and improve performance against low-flying targets.
In addition, due to the presence of frequency tuning, the performance of the radar in interference conditions has been improved. The radar data processing device uses new types of signal processors, and the remote control, monitoring and diagnostic system is improved.
The main set of 1L117M radar includes:
Machine No. 1 (transceiver) consists of: lower and upper antenna systems, a four-channel waveguide path with PRL transmitting and receiving equipment and state identification equipment;
Machine No. 2 has a collection cabinet (point) and an information processing cabinet, a radar indicator with remote control;
Vehicle No. 3 carries two diesel power plants (main and backup) and a set of radar cables;
Machines No. 4 and No. 5 contain auxiliary equipment (spare parts, cables, connectors, installation kit, etc.). They are also used for transporting disassembled antenna systems.
The overview of the space is provided by the mechanical rotation of the antenna system, which forms a V-shaped radiation pattern consisting of two beams, one of which is located in a vertical plane, and the other in a plane located at an angle of 45 to the vertical. Each radiation pattern in turn is formed by two beams formed at different carrier frequencies and having orthogonal polarization. The radar transmitter generates two consecutive phase-code-manipulated pulses at different frequencies, which are sent to the feeds of the vertical and inclined antennas through the waveguide path.
The radar can operate in low pulse repetition rate mode, providing a range of 350 km, and in frequent sending mode with a maximum range of 150 km. At higher rotation speeds (12 rpm), only the frequent mode is used.
The receiving system and digital equipment of the SDC ensure the reception and processing of target echo signals against the background of natural interference and meteorological formations. The radar processes echoes in a "moving window" with a fixed false alarm rate and has inter-view processing to improve target detection against background noise.
The SDC equipment has four independent channels (one for each receiving channel), each of which consists of a coherent and amplitude part.
The output signals of the four channels are combined in pairs, as a result of which normalized amplitude and coherent signals of the vertical and oblique beams are supplied to the radar extractor.
The information acquisition and processing cabinet receives data from the PLR and state identification equipment, as well as rotation and synchronization signals, and provides: selection of an amplitude or coherent channel in accordance with the interference map information; secondary processing of radar images with the construction of trajectories based on radar data, combining radar markers and state identification equipment, displaying the air situation on the screen with forms “linked” to targets; extrapolation of target location and collision prediction; introduction and display of graphic information; identification mode control; solving guidance (interception) problems; analysis and display of meteorological data; statistical assessment of radar operation; generation and transmission of exchange messages to control points.
The remote monitoring and control system ensures automatic operation of the radar, control of operating modes, performs automatic functional and diagnostic monitoring of the technical condition of equipment, identification and troubleshooting with display of methods for carrying out repair and maintenance work.
The remote monitoring system ensures localization of up to 80% of faults with an accuracy of a typical replacement element (REE), in other cases - up to a group of TEZ. The display screen of the workplace provides a complete display of characteristic indicators of the technical condition of radar equipment in the form of graphs, diagrams, functional diagrams and explanatory notes.
It is possible to transmit radar data via cable communication lines to remote display equipment for air traffic control and providing guidance and interception control systems. The radar is supplied with electricity from the included autonomous power supply; can also be connected to an industrial network 220/380 V, 50 Hz.
Radar station "Casta-2E1"
Designed to control airspace, determine the range and azimuth of air objects - airplanes, helicopters, remotely piloted aircraft and cruise missiles flying at low and extremely low altitudes, against the backdrop of intense reflections from the underlying surface, local objects and hydrometeorological formations.
The Kasta-2E1 mobile solid-state radar can be used in various systems for military and civil purposes - air defense, coastal defense and border control, air traffic control and airspace control in airfield areas.
Distinctive features of the station:
- block-modular construction;
- interfacing with various information consumers and issuing data in analog mode;
- automatic control and diagnostic system;
- additional antenna-mast kit for installing the antenna on a mast with a lifting height of up to 50 m
- solid-state radar construction
- high quality of output information when exposed to pulsed and noise active interference;
- the ability to protect and interface with means of protection against anti-radar missiles;
- the ability to determine the nationality of detected targets.
The radar includes a hardware machine, an antenna machine, an electrical unit on a trailer and a remote operator’s workstation, which allows you to control the radar from a protected position at a distance of 300 m.
The radar antenna is a system consisting of two mirror antennas with feeds and compensation antennas located on two floors. Each antenna mirror is made of metal mesh, has an oval contour (5.5 m x 2.0 m) and consists of five sections. This makes it possible to stack the mirrors during transportation. When using a standard support, the position of the phase center of the antenna system is ensured at a height of 7.0 m. Review in the elevation plane is carried out by forming one beam of a special shape, in azimuth - due to uniform circular rotation at a speed of 6 or 12 rpm.
To generate sounding signals in the radar, a solid-state transmitter is used, made on microwave transistors, which makes it possible to obtain a signal with a power of about 1 kW at its output.
Receiving devices carry out analog processing of signals from three main and auxiliary receiving channels. To amplify the received signals, a solid-state low-noise microwave amplifier is used with a transmission coefficient of at least 25 dB with an intrinsic noise level of no more than 2 dB.
The radar modes are controlled from the operator's workstation (OW). Radar information is displayed on a coordinate-sign indicator with a screen diameter of 35 cm, and the results of monitoring radar parameters are displayed on a table-sign indicator.
The Kasta-2E1 radar remains operational in the temperature range from -50 °C to +50 °C in conditions of precipitation (frost, dew, fog, rain, snow, ice), wind loads up to 25 m/s and the location of the radar on altitude up to 2000 m above sea level. The radar can operate continuously for 20 days.
To ensure high availability of the radar, there is redundant equipment. In addition, the radar kit includes spare equipment and accessories (SPTA) designed for a year of operation of the radar.
To ensure the readiness of the radar throughout its entire service life, group spare parts and accessories are supplied separately (1 set for 3 radars).
The average service life of the radar before major repairs is 1 15 thousand hours; The average service life before major repairs is 25 years.
The Kasta-2E1 radar has a high modernization capability in terms of improving individual tactical and technical characteristics (increasing potential, reducing the volume of processing equipment, display equipment, increasing productivity, reducing deployment and deployment time, increasing reliability, etc.). It is possible to supply the radar in a container version using a color display.
Radar station "Casta-2E2"
Designed to control airspace, determine range, azimuth, flight altitude and route characteristics of air objects - airplanes, helicopters, remotely piloted aircraft and cruise missiles, including those flying at low and extremely low altitudes, against the background of intense reflections from the underlying surface , local objects and hydro-meteorological formations. The low-altitude three-dimensional all-round radar of the standby mode "Casta-2E2" is used in air defense systems, coastal defense and border control, air traffic control and airspace control in airfield areas. Easily adapts to use in various civil systems.
Distinctive features of the station:
- block-modular construction of most systems;
- deployment and collapse of a standard antenna system using automated electromechanical devices;
- completely digital processing of information and the ability to transmit it via telephone channels and radio channels;
- completely solid-state construction of the transmission system;
- the possibility of installing the antenna on a light high-altitude support of the Unzha type, which ensures that the phase center is raised to a height of up to 50 m;
- the ability to detect small objects against the background of intense interfering reflections, as well as hovering helicopters while simultaneously detecting moving objects;
- high protection from asynchronous impulse interference when working in dense groups of radio-electronic equipment;
- a distributed complex of computing tools that provides automation of the processes of detection, tracking, measurement of coordinates and identification of the nationality of air objects;
- the ability to issue radar information to the consumer in any form convenient for him - analog, digital-analog, digital coordinate or digital trace;
- the presence of a built-in functional diagnostic monitoring system, covering up to 96% of the equipment.
The radar includes hardware and antenna vehicles, main and backup power plants, mounted on three KamAZ-4310 off-road vehicles. It has a remote operator workstation that provides control of the radar, located at a distance of 300 m from it.
The design of the station is resistant to the effects of excess pressure in the shock wave front, and is equipped with sanitary and individual ventilation devices. The ventilation system is designed to operate in recirculation mode without using intake air.
The radar antenna is a system consisting of a double-curvature mirror, a horn feed assembly, and side-lobe suppression antennas. The antenna system forms two beams with horizontal polarization along the main radar channel: sharp and cosecant, covering a given viewing sector.
The radar uses a solid-state transmitter made of microwave transistors, which makes it possible to receive a signal with a power of about 1 kW at its output.
The radar modes can be controlled either by operator commands or by using the capabilities of a complex of computing tools.
The radar ensures stable operation at ambient temperatures of ±50 °C, relative air humidity up to 98%, and wind speeds up to 25 m/s. The altitude above sea level is up to 3000 m. Modern technical solutions and element base used in the creation of the Kasta-2E2 radar made it possible to obtain tactical and technical characteristics at the level of the best foreign and domestic models.
Thank you all for your attention :)
SCIENCE AND MILITARY SECURITY No. 1/2007, pp. 28-33
UDC 621.396.96
THEM. ANOSHKIN,
Head of Department, Research Institute
Armed Forces of the Republic of Belarus,
Candidate of Technical Sciences, Senior Researcher
The principles of construction are presented and the capabilities of promising multi-position air defense radar systems are assessed, which will allow the armed forces of the United States and its allies to solve qualitatively new tasks in covert surveillance and control of airspace.
The constant growth of requirements for the volume and quality of radar information about the air and interference situation, ensuring high security of information means from the effects of enemy electronic warfare forces forces foreign military specialists not only to look for new technical solutions in the creation of various components of radar stations (radars), which are the main information sensors in air defense systems, air traffic control, etc., but also to develop new non-traditional directions in this area of development and creation of military equipment.
One of these promising areas is multi-position radar. Research and development carried out by the United States and a number of NATO countries (Great Britain, France, Germany) in this area are aimed at increasing the information content, noise immunity and survivability of radar equipment and systems for various purposes through the use of bistatic and multi-position operating modes in their operation. In addition, this ensures reliable surveillance of stealthy air targets, including cruise missiles and aircraft manufactured using Stealth technology, operating in conditions of electronic and fire suppression from the enemy, as well as reflections from the underlying surface and local items. A multi-position radar system (MPRS) should be understood as a set of transmitting and receiving points that ensure the creation of a radar field with the required parameters. The basis of the MPRS (as its individual cells) is made up of bistatic radars consisting of a transmitter and a receiver, spaced apart in space. When the transmitters are turned off, such a system, if there are appropriate communication lines between receiving points, can operate in passive mode, determining the coordinates of objects emitting electromagnetic waves.
To ensure increased secrecy of the operation of such systems in combat conditions, various principles of their construction are considered: ground-based, airborne, space-based and mixed-based variants that use probing radiation from standard radars, active enemy jammers, as well as radio systems (Fig. 1) that are non-traditional for radar (television and radio broadcasting stations, various communication systems and means, etc.). The most intensive work in this direction is being carried out in the USA.
The ability to have a radar field system that coincides with the coverage field formed by the illumination zones of television, radio broadcasting transmitting stations (RTBS), cellular telephone base stations, etc. is due to the fact that the height of their antenna towers can reach 50...250 m , and the omnidirectional illumination zone they form is pressed to the surface of the earth. The simplest recalculation using the line-of-sight range formula shows that aircraft flying at extremely low altitudes fall into the illumination field of such transmitters, starting from a distance of 50 - 80 km.
Unlike combined (monostatic) radars, the target detection zone of MPRS, in addition to the energy potential and radar surveillance conditions, largely depends on the geometry of their construction, the number and relative position of transmitting and receiving points. The concept of “maximum detection range” here is a quantity that cannot be unambiguously determined by the energy potential, as is the case for combined radars. The maximum detection range of a CC bistatic radar as an elementary cell of an MPRS is determined by the shape of the Cassini oval (lines of constant signal-to-noise ratios), which corresponds to a family of isodality curves or lines of constant total ranges (ellipses) that determine the position of the target on the oval (Fig. 2) in according to the expression
The radar equation for determining the maximum range of a bistatic radar has the form
Where rl,r2 - distances from the transmitter to the target and from the target to the receiver;
Pt- transmitter power, W;
G t, GT- gains of transmitting and receiving antennas;
Pmin - maximum sensitivity of the receiving device;
k- Boltzmann's constant;
v1, v2 - loss coefficients during the propagation of radio waves on the path from the transmitter to the target and from the target to the receiver.
The area of the detection zone of an MPRS, consisting of one transmitting and several receiving points (or vice versa), can significantly exceed the area of the detection zone of an equivalent combined radar.
It should be noted that the value of the effective scattering area (RCS) in a bistatic radar for the same target differs from its RCS measured in a single-position radar. When it approaches the base line (transmitter-receiver line) L the effect of a sharp increase in EPR is observed (Fig. 3), and the maximum value of the latter is observed when the target is on the base line and is determined by the formula
Where A - cross-sectional area of the object perpendicular to the direction of propagation of radio waves, m;
λ - wavelength, m.
Using this effect allows you to more effectively detect subtle targets, including those made using Stealth technology. A multi-position radar system can be implemented based on various variants of its construction geometry using both mobile and stationary receiving points.
The concept of MPRS has been developed in the United States since the early 1950s in the interest of using them to solve various problems, primarily control of aerospace. The work carried out was mainly theoretical, and in some cases experimental in nature. Interest in multi-position radar systems arose again in the late 1990s with the advent of high-performance computers and means for processing complex signals (radar, jamming, signals from radio and television transmitting stations, radio signals from mobile communication stations, etc.), capable of processing large volumes of radar information to achieve acceptable accuracy characteristics of such systems. In addition, the advent of the space radio navigation system GPS (Global Position System) allows for precise topographical location and strict time synchronization of MPRS elements, which is a necessary condition for correlation processing of signals in such systems. The radar characteristics of signals emitted by television (TV) and frequency-modulated (FM) radio broadcasting transmitting stations with radiotelephone stations of cellular GSM communications are given in Table 1.
The main characteristic of radio signals from the point of view of their use in radar systems is their uncertainty function (time-frequency error function or the so-called “uncertainty body”), which determines the resolution in terms of delay time (range) and Doppler frequency (radial speed). In general, it is described by the following expression
In Fig. 4 - 5 show the uncertainty functions of television image and audio signals, VHF FM radio signals and digital broadband audio broadcasting signals.
As follows from the analysis of the given dependencies, the uncertainty function of the TV image signal is multi-peak in nature, due to its frame and line periodicity. The continuous nature of the TV signal allows for frequency selection of echo signals with high accuracy, however, the presence of frame periodicity in it leads to the appearance of interfering components in its mismatch function, following at 50 Hz. A change in the average brightness of the transmitted TV image leads to a change in the average radiation power and a change in the level of the main and side peaks of its time-frequency mismatch function. An important advantage of the TV audio signal and frequency-modulated VHF broadcast signals is the single-peak nature of their uncertainty bodies, which facilitates the resolution of echo signals both in terms of delay time and Doppler frequency. However, their nonstationarity in the spectrum width has a strong influence on the shape and width of the central peak of the uncertainty functions.
Such signals in the traditional sense are not intended for solving radar problems, since they do not provide the required resolution and accuracy in determining the coordinates of targets. However, joint processing in real time of signals emitted by various different types of means, reflected from the digital center and simultaneously received at several receiving points, makes it possible to ensure the required accuracy characteristics of the system as a whole. For this purpose, it is envisaged to use new adaptive algorithms for digital processing of radar information and the use of high-performance computing tools of the new generation.
A feature of MPRS with external target illumination transmitters is the presence of powerful direct (penetrating) transmitter signals, the level of which can be 40 - 90 dB higher than the level of signals reflected from targets. To reduce the interfering influence of penetrating transmitter signals and reflections from the underlying surface and local objects in order to expand the detection zone, it is necessary to use special measures: spatial rejection of interfering signals, auto-compensation methods with frequency-selective feedback at high and intermediate frequencies, suppression at video frequencies, etc.
Despite the fact that work in this direction has been carried out for quite a long period, only recently, after the advent of relatively inexpensive ultra-high-speed digital processors that allow processing large volumes of information, for the first time did it become possible to create experimental samples that meet modern tactical and technical requirements.
Over the past fifteen years, specialists from the American company Lockheed Martin have been developing a promising three-dimensional radar system for detecting and tracking air targets based on multi-position design principles, which is called Silent Sentry.
It has fundamentally new capabilities for covert surveillance of the air situation. The system does not contain its own transmitting devices, which makes it possible to operate in passive mode and does not allow the enemy to determine the location of its elements using electronic reconnaissance. The covert use of the Silent Sentry MPRS is also facilitated by the absence of rotating elements and antennas in its receiving points with mechanical scanning of the antenna radiation pattern. The main sources providing the formation of sounding signals and target illumination are continuous signals with amplitude and frequency modulation emitted by television and radio broadcasting ultra-short wave transmitting stations, as well as signals from other radio equipment located in the system’s coverage area, including air defense and control radars air traffic, radio beacons, navigation, communications, etc. The principles of combat use of the Silent Sentry system are presented in Fig. 6.
According to the developers, the system will allow simultaneous tracking of a large number of computers, the number of which will be limited only by the capabilities of radar information processing devices. At the same time, the throughput of the Silent Sentry system (compared to traditional radar equipment, in which this indicator largely depends on the parameters of the radar antenna system and signal processing devices) will not be limited by the parameters of antenna systems and receiving devices. In addition, compared to conventional radars, which provide a detection range of low-flying targets of up to 40 - 50 km, the Silent Sentry system will allow them to be detected and tracked at ranges of up to 220 km due to the higher power level of signals emitted by television and radio broadcasting transmitting devices stations (tens of kilowatts in continuous mode), and by placing their antenna devices on special towers (up to 300 m or more) and natural elevations (hills and mountains) to ensure the maximum possible areas of reliable reception of television and radio broadcasts. Their radiation pattern is pressed to the surface of the earth, which also improves the system’s ability to detect low-flying targets.
The first experimental sample of a mobile receiving module of the system, which includes four containers with the same type of computing units (dimensions 0.5X0.5X0.5 m each) and an antenna system (dimensions 9X2.5 m), was created at the end of 1998. In the case of their mass production, the cost of one receiving module of the system will be, depending on the composition of the means used, from 3 to 5 million dollars.
A stationary version of the receiving module of the Silent Sentry system has also been created, the characteristics of which are given in table. 2. It uses a larger phased array antenna (PAA) than the mobile version, as well as computing capabilities that provide twice the performance of the mobile version. The antenna system is mounted on the side surface of the building, the flat phased array of which is directed towards the international airport. J. Washington in Baltimore (at a distance of about 50 km from the transmission point).
The separate stationary receiving module of the Silent Sentry system includes:
antenna system with phased array (linear or flat) of the target channel, providing reception of signals reflected from targets;
antennas of “reference” channels, providing reception of direct (reference) signals from target illumination transmitters;
a receiving device with a large dynamic range and systems for suppressing interfering signals from target illumination transmitters;
analog-to-digital converter of radar signals;
a high-performance digital processor for processing radar information manufactured by Silicon Graphics, which provides real-time data output on at least 200 air targets;
air condition display devices;
processor for analyzing the background-target situation, ensuring optimization of the choice at each specific moment of operation of certain types of probing radiation signals and target illumination transmitters located in the system’s coverage area in order to obtain the maximum signal-to-noise ratio at the output of the radar information processing device;
means of registration, recording and storage of information;
training and simulation equipment;
means of autonomous power supply.
The receiving phased array includes several subarrays developed on the basis of existing types of commercial antenna systems of various ranges and purposes. As experimental samples, it additionally includes conventional television receiving antenna devices. One phased array receiving canvas is capable of providing a viewing area in the azimuthal sector up to 105 degrees, and in the elevation sector up to 50 degrees, and the most effective level of reception of signals reflected from targets is provided in the azimuthal sector up to 60 degrees. To ensure overlap of a circular viewing area in azimuth, it is possible to use several phased array panels.
The appearance of the antenna systems, the receiving device and the screen of the situation display device for the stationary and mobile versions of the receiving module of the Silent Sentry system is shown in Figure 7. Tests of the system in real conditions were carried out in March 1999 (Fort Stewart, Georgia). At the same time, observation (detection, tracking, determination of spatial coordinates, speed and acceleration) in passive mode was provided for various aerodynamic and ballistic targets.
The main task of further work on the creation of the Silent Sentry system is currently related to improving its capabilities, in particular, introducing a target recognition mode. This problem is partially solved in already created samples, but not in real time. In addition, a version of the system is being developed in which it is planned to use onboard radars of long-range radar detection and control aircraft as target illumination transmitters.
In the UK, work in the field of multi-position radar systems for similar purposes has been carried out since the late 1980s. Various experimental samples of bistatic radar systems were developed and deployed, the receiving modules of which were deployed in the area of London Heathrow Airport (Fig. 8). Standard equipment from radio and television transmitting stations and air traffic control radars were used as target illumination transmitters. In addition, experimental samples of forward-scattering Doppler radars have been developed, using the effect of increasing the ESR of targets as they approach the base line of a bistatic system with television illumination. Research in the field of creating MPRS using radio-television transmitting stations as sources of irradiation of computers was carried out at the Research Institute of the Norwegian Ministry of Defense, which was reported at a session of leading Norwegian institutes and development companies on promising projects for the creation and development of new radio-electronic military equipment and technologies in June 2000 G.
Base stations of mobile cellular communications in the decimeter wavelength range can also be used as sources of signals probing the airspace. Work in this direction to create their own versions of passive radar systems is being carried out by specialists from the German company Siemens, the British companies Roke Manor Research and BAE Systems, and the French space agency ONERA.
It is planned to determine the location of the CC by calculating the phase difference of the signals emitted by several base stations, the coordinates of which are known with high accuracy. The main technical problem is ensuring the synchronization of such measurements within a few nanoseconds. It is supposed to be solved by using the technologies of highly stable time standards (atomic clocks installed on board spacecraft), developed during the creation of the Navstar space radio navigation system.
Such systems will have a high level of survivability, since during their operation there are no signs of using mobile telephone base stations as radar transmitters. If the enemy is somehow able to establish this fact, he will be forced to destroy all transmitters of the telephone network, which seems unlikely, given the current scale of their deployment. Identifying and destroying the receiving devices of such radar systems using technical means is practically impossible, since during their operation they use signals from a standard mobile telephone network. The use of jammers, according to the developers, will also be ineffective due to the fact that in the operation of the considered variants of the MPRS, a mode is possible in which the electronic radar devices themselves will turn out to be additional sources of illumination of air targets.
In October 2003, Roke Manor Research demonstrated to the British Ministry of Defense a version of the passive radar system Celldar (short for Cellular phone radar) during military exercises at the Salisbury Plain training ground. The cost of the demonstration prototype, consisting of two conventional parabolic antennas, two mobile phones (acting as “cells”) and a PC with an analog-to-digital converter, amounted to a little more than 3 thousand dollars. According to foreign experts, the military department of any country with a developed infrastructure mobile telephony, can create a similar 
nal radar systems. In this case, telephone network transmitters can be used without the knowledge of their operators. It will be possible to expand the capabilities of systems like Celldar through auxiliary means, such as, for example, acoustic sensors.
Thus, the creation and adoption of multi-position radar systems such as “Silent Sentry” or Celldar will allow the armed forces of the United States and its allies to solve qualitatively new tasks of covert surveillance and control of airspace in zones of possible armed conflicts in certain regions of the world. In addition, they can be involved in solving problems of air traffic control, combating the spread of drugs, etc.
As the experience of wars over the last 15 years shows, traditional air defense systems have low noise immunity and survivability, primarily from the effects of high-precision weapons. Therefore, the shortcomings of active radar systems should be neutralized as much as possible by additional means - passive means of reconnaissance of targets at low and extremely low altitudes. The development of multi-position radar systems using external radiation from various radio equipment was quite actively carried out in the USSR, especially in the last years of its existence. Currently, theoretical and experimental research on the creation of MPRS is ongoing in a number of CIS countries. It should be noted that similar work in this field of radar is being carried out by domestic specialists. In particular, an experimental bistatic radar “Pole” was created and successfully tested, where radio and television transmitting stations are used as target illumination transmitters.
LITERATURE
1. Jane's Defense Equipment (Electronic library of weapons of the world), 2006 - 2007.
2. Peter W. Davenport. Using Multistatic Passive Radar for Real-Time Detection of UFO"S in the Near-Earth Environment. - Copyright 2004. - National UFO Reporting Center, Seattle, Washington.
3. H. D. Griffiths. Bistatic and Multistatic Radar. - University College London, Dept. Electronic and Electrical Engineering. Torrington Place, London WC1E 7JE, UK.
4. Jonathan Bamak, Dr. Gregory Baker, Ann Marie Cunningham, Lorraine Martin. Silent Sentry™ Passive Surveillance // Aviation Week&Space Technology. - June 7, 1999. - P.12.
5. Rare access: http://www.roke.co/. uk/sensors/stealth/celldar.asp.
6. Karshakevich D. The phenomenon of the “Field” radar // Army. - 2005 - No. 1. - P. 32 - 33.
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I reported to the President that the Aerospace Forces, in accordance with the army and navy rearmament program adopted in 2012, have already received 74 new radar stations. This is a lot, and at first glance, the state of radar reconnaissance of the country's airspace looks good. However, there remain serious unresolved problems in this area in Russia.
Effective radar reconnaissance and airspace control are essential conditions for ensuring the military security of any country and the safety of air traffic in the skies above it.
In Russia, the solution to this problem is entrusted to the radar of the Ministry of Defense and.
Until the early 1990s, the systems of military and civilian departments developed independently and practically self-sufficiently, which required serious financial, material and other resources.
However, the conditions for airspace control became increasingly complicated due to the increasing intensity of flights, especially by foreign airlines and small aircraft, as well as due to the introduction of a notification procedure for the use of airspace and the low level of equipping civil aviation with responders to the unified state radar identification system.
Control over flights in the “lower” airspace (zone G according to the international classification), including over megacities and especially in the Moscow zone, has become sharply more complicated. At the same time, the activities of terrorist organizations capable of organizing terrorist attacks using aircraft have intensified.
The airspace control system is also influenced by the emergence of qualitatively new surveillance equipment: new dual-purpose radars, over-the-horizon radars and automatic dependent surveillance (ADS) equipment, when, in addition to secondary radar information from the monitored aircraft, parameters are transmitted directly to the controller from the aircraft’s navigation instruments, and etc.
In order to streamline all available surveillance means, in 1994 it was decided to create a unified system of radar equipment of the Ministry of Defense and the Ministry of Transport within the framework of the federal system of reconnaissance and airspace control of the Russian Federation (FSR and KVP).
The first regulatory document that laid the foundation for the creation of the FSR and KVP was the corresponding decree of 1994.
According to the document, we were talking about an interdepartmental dual-use system. The purpose of creating the FSR and KVP was declared to combine the efforts of the Ministry of Defense and the Ministry of Transport to effectively solve the problems of air defense and traffic control in Russian airspace.
As work was progressing to create such a system from 1994 to 2006, three more presidential decrees and several government decrees were issued. This period of time was spent mainly on the creation of regulatory legal documents on the principles of the coordinated use of civilian and military radars (Ministry of Defense and Rosaviation).
From 2007 to 2015, work on the FSR and KVP was carried out through the State Armaments Program and a separate federal target program (FTP) “Improving the federal system of reconnaissance and control of the airspace of the Russian Federation (2007-2015).” Was approved as the lead contractor for the implementation of the Federal Target Program. According to experts, the amount of funds allocated for this was at the minimum acceptable level, but the work has finally begun.
State support made it possible to overcome the negative trends of the 1990s and early 2000s to reduce the country's radar field and create several fragments of a unified automated radar system (ERLS).
Until 2015, the area of airspace controlled by the Russian Armed Forces was growing steadily, and the required level of air traffic safety was maintained.
All the main activities provided for by the Federal Target Program were completed within the established indicators, but it did not provide for the completion of work on the creation of a unified radar system (ERLS). Such a reconnaissance and airspace control system was deployed only in certain parts of Russia.
At the initiative of the Ministry of Defense and with the support of the Federal Air Transport Agency, proposals were developed for the continuation of the program that had been started but not completed in order to fully deploy a unified reconnaissance and airspace control system over the entire territory of the country.
At the same time, the “Concept of Aerospace Defense of the Russian Federation for the period up to 2016 and beyond,” approved by the President of Russia on April 5, 2006, assumes the full-scale deployment of a unified federal system by the end of last year.
However, the corresponding federal target program expired in 2015. Therefore, back in 2013, following a meeting on the implementation of the State Armament Program for 2011-2020, the President of Russia instructed the Ministry of Defense and the Ministry of Transport, together with, to submit proposals for amending the Federal Target Program “Improving the federal system of reconnaissance and control of the airspace of the Russian Federation (2007- 2015)" with the extension of this program until 2020.
The corresponding proposals were supposed to be ready by November 2013, but Vladimir Putin’s order was never implemented, and work to improve the federal reconnaissance and airspace control system has not been funded since 2015.
The previously adopted Federal Target Program expired, and the new one was never approved.
Previously, coordination of relevant work between the Ministry of Defense and the Ministry of Transport was assigned to the Interdepartmental Commission for the Use and Control of Airspace, formed by presidential decree, which was abolished back in 2012. After the liquidation of this body, there was simply no one to analyze and develop the necessary regulatory framework.
Moreover, in 2015, the position of general designer was eliminated in the federal system of reconnaissance and airspace control. The coordination of the FSR and KVP bodies at the state level has virtually ceased.
At the same time, competent specialists now recognize the need to improve this system by creating a promising integrated dual-use radar (IRLS DN) and combining the FSR and KVP with a reconnaissance and warning system for an aerospace attack.
A new dual-use system must have, first of all, the advantages of a single information space, and this is only possible by solving many technical and technological problems.
The need for such measures is evidenced by the complication of the military-political situation and the strengthening of threats from aerospace in modern warfare, which have already led to the creation of a new type of armed forces - the Aerospace.
In the aerospace defense system, the requirements for FSR and KVP will only increase.
Among them is ensuring effective continuous control in the airspace of the state border along its entire length, especially in the likely directions of attack by aerospace attack weapons - in the Arctic and in the southern direction, including the Crimean Peninsula.
This necessarily requires new funding for the FSR and KVP through the relevant federal target program or in another form, the re-establishment of a coordinating body between the Ministry of Defense and the Ministry of Transport, as well as the approval of new program documents, for example until 2030.
Moreover, if previously the main efforts were aimed at solving the problems of airspace control in peacetime, then in the coming period the priority tasks will be to warn of an air attack and provide information support for combat operations to repel missile and air strikes.
- military observer for Gazeta.Ru, retired colonel.
Graduated from the Minsk Higher Engineering Anti-Aircraft Missile School (1976),
Military Command Academy of Air Defense (1986).
Commander of the S-75 anti-aircraft missile division (1980-1983).
Deputy commander of the anti-aircraft missile regiment (1986-1988).
Senior officer of the main headquarters of the Air Defense Forces (1988-1992).
Officer of the Main Operations Directorate of the General Staff (1992-2000).
Graduate of the Military Academy (1998).
Columnist "" (2000-2003), editor-in-chief of the newspaper "Military-Industrial Courier" (2010-2015).
The invention relates to the field of radar and can be used in the development of promising radars. The achieved technical result is to increase the reliability of object detection. To do this, in the known method of monitoring airspace, which consists in reviewing it using a radar, they additionally receive the reflected energy of an external radio-electronic device (RES), determine the boundaries of the zone in which the ratio of the RES energy reflected by the object to noise is greater than the threshold value, and emit a radar signal only in those directions of the zone in which the reflected energy of the RES is detected.
The invention relates to the field of radar and can be used in the development of promising radars. To ensure airspace control, it is necessary to detect an object with high reliability and measure its coordinates with the required accuracy. There is a known method for detecting an object using passive multi-position systems that use irradiation of the object due to the energy of external radio-electronic means (RES), for example telecentres or even natural sources: lightning, the sun, some stars. Detection of an object and measurement of its coordinates in this method is carried out by receiving energy (signals) reflected by the object from external sources at spaced points and joint processing of the received signals. The advantage of this method is that its operation does not require energy consumption to irradiate the object. In addition, it is known that the effective scattering area of an object during bistatic transmission radar in the zone of existence of the transmission effect is 3-4 orders of magnitude larger compared to monostatic radar. This means that an object can be detected when it is irradiated through light with a relatively low level of RES energy. The disadvantages of the method are as follows: - to implement the method, it is necessary to have several spaced receiving positions with a communication system between them, since with one position you can only detect a sign of the presence of an object, and to measure its coordinates you need at least three; - only RES with a signal having a spectrum width sufficient to ensure range resolution of objects can be used; - it is impossible to ensure control of the entire space when using RES with real energy potential, because It is impossible to ensure the required ratio of RES energy/noise reflected by the object at an arbitrary position of the object in the controlled space, since, as shown in (graphs in Fig. 3, p. 426), the transmission effect operates at diffraction angles of approximately 6 degrees. The closest technical solution is the method of monitoring airspace using radar, when a probing signal is emitted sequentially in all directions of the controlled space and, based on the signal received by the object reflected, it is detected and its coordinates are measured. As a rule, for this purpose they use a radar with a needle-shaped antenna pattern in the S-band, for example, the RAT-31S radar (Radioelectronics abroad, 1980, 17, p. 23). The disadvantage of this method is that even with a needle beam, the concentration of energy when examining each direction is insufficient to detect an inconspicuous object, since in a short viewing period (a few seconds) it is necessary to inspect a controlled space consisting of thousands of directions. This reduces the reliability of object detection. It can be increased by increasing the concentration of energy in the direction being inspected by increasing the potential of the radar. This is not possible for mobile radars. An increase in energy concentration in the direction being inspected while conserving energy can be achieved by reducing the number of inspection directions, which is also not possible, because shortened directions will fall out of control. The proposed invention is aimed at solving the problem of increasing the reliability of object detection while maintaining the energy potential of the radar. The problem is solved by reducing the number of inspection directions using radar in those zones of space in which, when an object is located, reliable reception of the energy reflected by external electronic zones is ensured. This result is achieved by the fact that in the known method of monitoring airspace, which consists in reviewing it using a radar, according to the invention, they additionally receive the reflected energy of an external radio-electronic device (RES), determine the boundaries of the zone in which the ratio of the energy of the RES reflected by the object to noise is greater than the threshold value , and emit the radar signal only in those directions of the zone in which the reflected energy of the RES is detected. The essence of the invention is as follows. A specific RES with known parameters is determined, the energy of which will be used to detect an object (for example, a television satellite, communications satellite or terrestrial RES). The value of the ratio of the RES energy/noise reflected by the object (i.e., the signal/noise ratio) at the reception point is determined using the formula (LZ, formula 1, p. 425): 
where Q= P C /P Ш - signal-to-noise ratio; P T - average power of the RES transmitting device; G T , G R are the gains of the transmitting and receiving antennas, respectively; - wavelength; - generalized losses; (B, D)) - ESR of the object for a two-position system as a function of the diffraction angles B and G; F(,) F(,) - pattern of transmitting and receiving antennas; Р Ш - average noise power in the receiving device band, taking into account the detection threshold; R T , R R - distance from the electronic zone and the receiving device to the object, respectively. For a Q value greater than the threshold value, i.e. ensuring the required reliability of detecting the RES energy reflected by the object, the boundary values B, G are determined, which are taken as the boundaries of the zone in which the object is located, the ratio of the RES energy reflected by the object to noise is greater than the threshold value. In the case of using a stably operating RES, the zone where Q exceeds the threshold value can be determined experimentally by collecting statistics while reviewing the zone simultaneously in passive mode and using the radar. At the same time, the boundaries of the zone are determined in which the reflected RES energy by the object detected by the radar is detected with the required reliability. After determining the boundaries, the zone is inspected in passive mode using a receiving antenna in the frequency range of the selected RES in a known manner (see, for example,), the radar is not used to survey this zone. when detecting in a certain direction o , o , entering the zone of energy reflected by an object, the RES make a decision to detect a sign of the location of an object in this direction and emits a radar signal in this direction, in the active mode they detect the object and measure its coordinates. Thus, the number of directions surveyed by radar will be reduced; due to this, the concentration of radar energy can be increased when inspecting spatial directions, which will increase the reliability of object detection. It should be noted that the energy of the external RES in the proposed invention is used only to detect a sign of the presence of an object, in contrast, for example, to the method described in, where it is used to detect an object and measure its coordinates. This eliminates the main disadvantages of the method of using external RES, noted in, and reduces the requirements for the radiation parameters of RES.
Claim
A method for monitoring airspace, which consists in viewing it using a radar, characterized in that it additionally receives the energy of an external radio-electronic device (RES) reflected by the object, determines the boundaries of the zone in which the ratio of the RES energy reflected by the object to noise is greater than a threshold value, and emits a radar signal only in those directions of the zone in which the reflected energy of the RES is detected.
Other changes related to registered inventions
Changes: The transfer of the exclusive right without concluding an agreement was registered. Date and number of state registration of the transfer of the exclusive right: 03/12/2010/RP0000606 Patent holder: Open Joint-Stock Company "Scientific Research Institute of Measuring Instruments"
Former patent holder: Federal State Unitary Enterprise "Research Institute of Measuring Instruments"
Number and year of publication of the bulletin: 30-2003
Similar patents:
The invention relates to passive radio equipment for determining the location of sources of pulsed electromagnetic radiation and can be used to measure the location of lightning discharges at distances of 300-2000 km in meteorology and civil aviation to improve flight safety
The invention relates to radio engineering and is intended for precision determination of satellite flight altitude, parameters of the Earth's gravitational field, determination of the geoid figure, land surface topography, topography of ice fields and the ocean, in particular the height of irregularities of the underlying surface and ocean waves
Introduction
1. Theoretical part
1.1. General characteristics of ATC radar
1.2. Objectives and main parameters of the radar
1.3. Features of primary radars
1.4. Track surveillance radar "Skala - M"
1.5. Features of the functional units of the Scala-M radar
1.6. Patent search
2. Safety and environmental friendliness of the project
2.1. Safe organization of the PC engineer’s workplace
2.2. Potentially dangerous and harmful production factors when working with PCs
2.3. Ensuring electrical safety when working with PCs
2.4 Electrostatic charges and their dangers
2.5. Ensuring electromagnetic safety
2.6. Requirements for premises for PC operation
2.7. Microclimatic conditions
2.8. Noise and vibration requirements
2.9. . Requirements for the organization and equipment of workstations with monitors and PCs
2.10. Illumination calculation
2.11. Environmental friendliness of the project
Conclusion
Bibliography
INTRODUCTION
Radar stations of the air traffic control system (ATC) are the main means of collecting information about the air situation for traffic control personnel and a means of monitoring the progress of the flight plan, and also serve to provide additional information on observed aircraft and the situation on the runway and taxiways. Meteorological radars intended for the operational supply of command, flight and dispatch personnel with data on the meteorological situation can be identified as a separate group.
The standards and recommendations of ICAO and the CMEA Standing Commission on Radio Engineering and Electronics Industry provide for the division of radar equipment into primary and secondary. Often, primary radar stations (PRLS) and VSRLS are combined based on the principle of functional use and are defined as a radar complex (RLC). However, the nature of the information received, especially the construction of equipment, allows us to consider these stations separately.
Based on the above, it is advisable to combine the radar into the following trust surveillance radars ORL-T with a maximum range of about 400 km;
ORL-TA route and air hub radars with a maximum range of about 250 km;
airfield surveillance radars ORL-A (variants V1, V2, VZ) with a maximum range of 150, 80 and 46 km, respectively;
landing radars (PLL);
secondary radars (SSR);
combined surveillance and landing radars (CSRL);
airfield surveillance radars (AFR);
weather radars (MRL).
This course work examines the principle of constructing an air traffic control radar.
1. Theoretical part
1.1. General characteristics of ATC radar
radar control air traffic
Modern authorized air traffic control (ATC) systems (AS) use third-generation radars. Re-equipment of civil aviation enterprises usually takes a long period, therefore, currently, along with modern radars, radars of the second and even first generations are used. Radars of different generations differ, first of all, in the element base, methods of processing radar signals and protecting the radar from interference.
First generation radars began to be widely used in the mid-60s. These include route radars of the P-35 type and airfield radars of the Ekran type. These radars are built on electric vacuum devices using hinged elements and volumetric installation.
Second generation radars began to be used in the late 60s - early 70s. Increasing requirements for the sources of radar information of the air traffic control system has led to the fact that radars of this generation have turned into complex multi-mode and multi-channel radar systems (RLC). The second generation radar complex consists of a radar with a built-in radar channel and primary information processing equipment (API). The second generation includes the trust radar complex "Skala" and the airfield radar complex "Irtysh". In these complexes, along with electric vacuum devices, solid-state elements, modules and micromodules in combination with mounting based on printed circuit boards began to be widely used. The main scheme for constructing the primary radar channel was a two-channel scheme with frequency separation, which made it possible to increase reliability indicators and improve detection characteristics compared to the first generation radars. Second-generation radars began to use more advanced means of protection against interference.
Operating experience with second-generation radars and radar systems has shown that, in general, they do not fully satisfy the requirements of automated air traffic control systems. In particular, their significant disadvantages include the limited use of modern digital signal processing equipment in the equipment, the small dynamic range of the receiving path, etc. Radar and radar data are currently used in manual and automated air traffic control systems.
Primary radars and third-generation radars began to be used in civil aviation in our country as the main sources of radar information from air traffic control systems since 1979. The main requirement that determines the features of third-generation radars and radars is to ensure a stable level of false alarms at the radar output. This requirement is met thanks to the adaptive properties of the third generation primary radars. Adaptive radars perform real-time analysis of the interference environment and automatic control of the radar operating mode. For this purpose, the entire radar coverage area is divided into cells, for each of which, as a result of analysis over one or more review periods, a separate decision is made on the current interference level. Adaptation of the radar to changes in the interference environment ensures stabilization of the level of false alarms and reduces the risk of overloading the APOI and data transmission equipment to the air traffic control center.
The elemental base of third-generation radars and radars are integrated circuits. In modern radars, elements of computer technology and, in particular, microprocessors, which serve as the basis for the technical implementation of adaptive systems for processing radar signals, are beginning to be widely used.
1.2. Objectives and main parameters of the radar
The purpose of the radar is to detect and determine the coordinates of aircraft (AC) in the radar's area of responsibility. Primary radar stations make it possible to detect and measure the slant range and azimuth of an aircraft using the active radar method, using radar sounding signals reflected from targets. They operate in pulse mode with high (100 ... 1000) duty cycle. All-round visibility of the controlled airspace is carried out using a rotating antenna with a highly directional bottom in the horizontal plane.
In table 1 shows the main characteristics of surveillance radars and their numerical values, regulated by CMEA-ICAO standards.
The radars under consideration have a significant number of common features and often perform similar operations. They are characterized by identical structural diagrams. Their main differences are due to various features of functional use in a hierarchically complex ATC system.
1.3. Features of primary radars
A typical block diagram of a primary radar (Fig. 1) consists of the following main components: an antenna-feeder system (AFS) with a drive mechanism (MFA); angular position sensor (ROS) and side lobe suppression channel (SL); transmitter (Tr) with an automatic frequency control device (AFC); receiver (Prm); signal extraction and processing equipment (SEP) - in a number of modern and promising radar stations and complexes, combined with a receiver into a signal processing processor; synchronizing device (SU), signal transmission path to external processing and display devices (TS); control indicating device (CM), usually operating in the “Analog” or “Synthetic” mode; built-in control systems (BCS).
The main antenna, which is part of the APS, is designed to form a beam pattern having a width of 30 ... 40º in the vertical plane, and a width of 1 ... 2° in the horizontal plane. The small width of the bottom in the horizontal plane provides the required level of azimuth resolution. To reduce the influence of the aircraft detection range on the level of reflection of signals from the target, the bottom beam in the vertical plane often has a shape that obeys the law Cosec 2 θ, where θ is the elevation angle.
The suppression channel for the side lobes of the interrogation antenna (when the radar is operating in active mode, i.e., when using a built-in or parallel operating SSR) is designed to reduce the likelihood of false alarms of the aircraft transponder. Structurally, the system for suppressing side lobes by response is simpler.
Most radars in the AFS use two feeders, one of which provides detection of aircraft at low altitudes, i.e., at low elevation angles. A feature of the pattern in the vertical plane is the gradation of its configuration, especially in the lower part, which reduces interference from local objects and the underlying surface. In order to increase the flexibility of radar adjustment, it is possible to change the maximum of the beam at angle 9 within 0 ... 5º relative to the horizontal plane. The APS includes devices that allow you to change the polarization characteristics of emitted and received signals. For example, the use of circular polarization makes it possible to attenuate signals reflected from meteorological formations by 15 ... 22 dB.
The antenna reflector, made of a metal mesh, is close in shape to a truncated paraboloid of rotation. Modern ATC radars also use radio-transparent coatings that protect the AFS from precipitation and wind load. SSR antennas and a suppression channel antenna are mounted on the antenna reflector.
The antenna drive mechanism ensures its uniform rotation. The antenna rotation frequency is determined by the information support requirements of traffic controllers responsible for various stages of the flight. As a rule, there are options for sectoral and circular views of the space.
The aircraft azimuth is determined by reading information in the coordinate system specified for the radar indicating device. Antenna angular position sensors are designed to receive discrete or analog signals that are basic for the selected coordinate system.
The transmitter is designed to receive radio pulses with a duration of 1 ... 3 μs. The frequency range of operation is selected based on the purpose of the radar. In order to reduce losses caused by target fluctuations, increase the number of pulses reflected from the target in one review, and also to combat blind speeds, dual-frequency space sensing is used. In this case, the operating frequencies differ by 50...100 MHz.
The time characteristics of the probing pulses depend on the functional use of the radar. ORL-T uses probing pulses with a duration of about 3 x, followed by a repetition rate of 300 ... 400 Hz, and ORL-A has a pulse duration of no more than 1 μs at a repetition rate of 1 kHz. The transmitter power does not exceed 5 MW.
To ensure the specified accuracy of the frequency of the generated microwave oscillations, as well as for the normal operation of the SDC circuit, an automatic frequency control device (AFC) is used. A stable local oscillator of the receiver is used as a source of reference oscillations in AFC devices. The speed of auto-adjustment reaches several megahertz per second, which reduces the impact of the automatic frequency control on the efficiency of the SDC system. The value of the residual detuning of the real frequency value in relation to the nominal value does not exceed 0.1 ... 0.2 MHz.
Signal processing according to a given algorithm is carried out in the radar receiving and analyzing device in the case when Prm and AVOS are practically indistinguishable.
In general, the receiver performs the functions of selecting, amplifying and converting received echo signals. A feature of radar receivers is the presence of a low-noise high-frequency amplifier, which makes it possible to reduce the noise figure of the receiver and thereby increase the target detection range. The average noise figure of receivers is in the range of 2 ... 4 dB, and the sensitivity is 140 dB/W. The intermediate frequency is usually 30 MHz, double frequency conversion is practically not used in air traffic control radars, the IF gain is about 20 ... 25 dB. In some radars, amplifiers with LAX are used to expand the dynamic range of input signals.
In turn, to narrow the range of input signals supplied to the APOI, an AGC is used, as well as a VAG, which increases the gain of the amplifier when operating at maximum detection ranges.
From the output of the amplifier, the signals go through the amplitude and phase channels
detection.
Temporary signal processing equipment (TSP) performs the function of filtering a useful signal against a background of interference. The greatest intensity is caused by unintentional interference from radio equipment located within a radius of up to 45 km from the radar.
Hardware for combating electromagnetic interference includes special switching and control devices for radiation patterns, VAG circuits that reduce the dynamic range of input signals from nearby targets, blanking devices for the receiving and analyzing path, filters for synchronous and asynchronous interference, etc.
An effective means of combating interference from targets that are stationary or weakly changing their position in space and time are moving target selection systems (MSS), which implement single- or double-period compensation methods. In a number of modern radars, the moving target selection device (MTS) implements a digital processing algorithm in quadrature channels, having a coefficient of suppression of interference from stationary objects of 40 ... 43 dB, and from meteorological interference up to 23 dB.
The output devices of the AVOS are parametric and non-parametric signal detectors, which make it possible to stabilize the probability of a false alarm at the level of 10 -6.
In digital signal processing, AVOS is a specialized microprocessor.
1.4. Track surveillance radar "Skala - M"
The radar under consideration is a complex that includes the PRL and the secondary “Root” channel. The radar is designed for monitoring and control and can be used both in automated air traffic control systems and in non-automated air traffic control centers.
The main parameters of the Skala-M radar are given below.
The block diagram of the Skala-M radar is shown in Fig. 2. It consists of a primary radar channel (PRC), a secondary radar channel (SRC), primary information processing equipment (PIE) and a switching device (CU).
The PRK includes: PU polarization devices; rotating transitions VP, two power addition units BSM1 (2); antenna switches AP1 (2, 3); transmitters Prd (2, 3); BRS signal separation unit; receivers Prm 1 (2, 3); SDC moving target selection system; device for forming a FZO detection zone and a CI control indicator. The secondary radar channel includes: AVRL SSR antenna system; aircraft transponder type COM-64, used as a device that controls the operation of the VRK-SO; FU feeder device; transceiver device used in the “RBS” mode of the PP; SG matching device and receiving device used in ATC-PRM mode.
The collection and transmission of information is carried out using a broadband radio relay line SRL and a narrowband transmission line ULP.
The primary channel of the radar is a two-channel device and operates at three fixed frequencies. The bottom beam of the bottom beam is formed by the main channel feed, and the top beam by the feed of the high-flying target indication channel (HTC). The radar implements the ability to simultaneously process information in coherent and amplitude modes, which makes it possible to optimize the viewing area, shown in Fig. 3.
The boundaries of the detection zone are set depending on the interference situation. Their choice is determined by the pulses generated in the CI, which control switching in the APOI and video path.
Section 1 has a length of no more than 40 km. Information is generated using signals from the upper beam. In this case, the suppression of reflections from local objects in the near zone is 15 ... 20 dB.
In section 2, the signals of the upper beam are used when the receiving-analyzing device is operating in amplitude mode and the signals of the lower beam processed in the SDC system, and in the channel of the lower beam a VAG is used, which has a dynamic range of 10 ... 15 dB greater than in the channel of the upper beam, which provides control over the location of aircraft located at low elevation angles.
The second section ends at such a distance from the radar that the echo signals from local objects received by the lower beam have an insignificant level.
Section 3 uses signals from the upper beam, and section 4 uses signals from the lower beam. The amplitude processing mode is carried out in the receiving and analyzing path.
Wobbling the radar launch frequency allows you to eliminate gaps in the amplitude-velocity characteristic and eliminate the ambiguity of the reading. The PRDZ has a repetition frequency of probing signals of 1000 Hz, and the first two have a repetition rate of 330 Hz. The increased repetition rate increases the efficiency of the SDC by reducing the influence of fluctuations of local objects and antenna rotation.
The operating principle of the PRK equipment is as follows.
High-frequency signals from transmitting devices are fed through antenna switches to power combining devices and then through rotating joints and a polarization control device to the lower beam feed. Moreover, in sections 1 and 2 of the detection zone, signals from the first transceiver are used, arriving along the upper beam and processed in the SDC. On 3 - composite signals arriving along both beams and processed in the amplitude channel of the first and second transceivers, and on 4 - signals from the first and second transceivers, arriving along the lower beam and processed in the amplitude channel. If any of the sets fails, a third transceiver automatically takes its place.
Power summing devices filter the echo signals received by the lower beam and, depending on the carrier frequency, transmit them through the AP to the corresponding receiving and analyzing devices. The latter have separate channels for processing signals from the main beam and the beam of the high-flying target indication channel (HTC). The ITC channel works for reception only. Its signals pass through a polarization device and, after a signal separation unit, arrive at three receivers. The receivers are made using a superheterodyne circuit. Amplification and processing of intermediate frequency signals is performed in a two-channel amplifier. In one channel the signals from the upper beam are amplified and processed, in the other - from the lower beam.
Each of the similar channels has two outputs: after amplitude signal processing and at intermediate frequency for phase detectors of the SDC system. Phase detectors separate out the in-phase and quadrature components.
After the SDC, the signals arrive at the APOI, are combined with the VRK signals and are then fed to the equipment for displaying and processing radar information. In the ATC automated system, the CX-1000 extractor can be used as an APOI. and as broadcast devices, CH-2054 modems.
The secondary radar channel ensures the receipt of coordinate and additional information from aircraft equipped with transponders in the “ATC” or “RBS” modes. The shape of the signals in the request mode is determined by ICAO standards, and when received - by the ICAO standards or the domestic channel, depending on the operating mode of the transponders. The block diagram and parameters of the secondary channel equipment are similar to the autonomous SSR of the “Koren-AS” type.
1.5. Features of the functional units of the Scala-M radar
The antenna-feeder device PRK consists of an antenna that forms the bottom, and a feeder path containing switching devices.
Structurally, the primary channel antenna is made in the form of a parabolic reflector measuring 15x10.5 m and two horn feeds. The lower beam is formed by a single-horn feed of the main channel and a reflector, and the upper beam is formed by a reflector and a single-horn feed located below the main one. The shape of the pattern in the vertical plane cosec 2 θ, where θ is the elevation angle. Its appearance is shown in Fig. 4.
To reduce reflections from meteorological formations, a polarizer of the main channel is provided, which provides a smooth change in the polarization of the emitted signals from linear to circular, and a polarizer of the IVC channel, constantly built for circular polarization.
The isolation between power adding devices is at least 20 dB, and the isolation between individual channels is at least 15 dB. The waveguide path provides the possibility of recording a standing wave coefficient of at least 3, with a measurement error of 20%.
The formation of the bottom of the secondary channel is carried out by a separate antenna, similar to the SSR antenna of the “Koren - AS” type, located on the reflector of the main antenna. At ranges exceeding 5 km, a signal suppression sector along the side lobes within 0..360º is provided.
Both antennas are placed above a radio-transparent dome, which can significantly reduce wind load and increase weather protection.
The transmitting equipment of the primary channel is designed to generate microwave pulses with a duration of 3.3 μs with an average power per pulse of 3.6 kW, as well as to generate intermediate frequency reference signals for phase detectors and heterodyne frequency signals for mixers of receiving-analyzing paths. The transmitters are made according to the standard principle for truly coherent radars, which allows one to obtain sufficient phase stability. Carrier frequency signals are obtained by converting the frequency of the intermediate frequency master oscillator, which has quartz stabilization.
The final stage of the transmitter is a power amplifier made on a fly-through klystron. The modulator is designed as a full-discharge storage device consisting of five parallel-connected modules. Carrier frequencies and local oscillator frequencies have the following values: f 1 =1243 MHz; f G1 =1208 MHz; f 2 =1299 MHz; f G2 =1264 MHz; f 3 =1269 MHz; f G3 =1234 MHz.
The receiving path of the PRK is designed to amplify, select, convert, detect echo signals, as well as attenuate signals reflected from meteorological formations.
Each of the three receiving-analyzing paths has two channels - the main one and the indication of high-altitude targets and is made according to a superheterodyne circuit with a single frequency conversion. The output signals from the receivers are fed to the SDC (at intermediate frequency) and to the detection zone shaper - video signals.
The receivers process signals in linear and logarithmic amplitude subchannels, as well as in a coherent subchannel, thereby stabilizing the level of false alarms to the level of intrinsic noise in a logarithmic video amplifier.
Partial restoration of the dynamic range is carried out using video amplifiers with an antilogarithmic amplitude response. To compress the dynamic range of echo signals at short ranges, as well as to attenuate false reception along the side lobes of the bottom, a VAG is used. It is possible to temporarily blank one or two areas during intense interference.
In each receiving channel, the specified noise levels are maintained (SHARU circuit) at the channel outputs with an accuracy of at least 15%.
The SDC digital device has two identical channels in which the in-phase and quadrature components are processed. The output signals from the phase detectors, after processing in the input devices, are approximated by a step function with a sampling step of 27 μs. They are then sent to the ADC, where they are converted into 8-bit code and entered into storage and computing devices. The storage device is designed to store an 8-bit code in 960 range quanta.
The SDC provides the possibility of double and triple inter-period subtraction of signals. Quadratic addition is carried out in the module extractor, and the LOG-MPV-ANTILOG device selects video pulses by duration and restores the dynamic range of the output video pulses. The recirculation storage device provided in the circuit allows to increase the signal-to-noise and is a means of protection against asynchronous impulse noise. From it, the signals are sent to the DAC, amplified and fed to the APOI and KU. The operating range of the SDC at the repetition frequency fп=330 Hz is 130 km, fп=1000Hz is 390 km, and the signal suppression coefficient from stationary objects is 40 dB.
1.6. Patent search
The third generation radar discussed above appeared in the 80s. There are a large number of similar complexes in the world. Let's look at several patented ATC devices and their characteristics.
In the United States in 1994, several patents appeared for various air traffic control radars.
920616 Volume 1139 No. 3
Method and device for ground radar information reproduction system .
The air traffic control (ATC) system contains a detection radar, a beacon and a common digital encoder to track aircraft and eliminate the possibility of collisions. During the transmission of data to the ATC system, data is collected from a common digital encoder, and range and azimuth data are collected for all tracked aircraft. From the general data array, data that is not related to the location of the escorted aircraft is filtered out. As a result, a trajectory message with polar coordinates is generated. Polar coordinates are converted to rectangular coordinates, after which a data block is generated and encoded, carrying information about all aircraft accompanied by the ATC system. The data block is generated by the auxiliary computer. The data block is read into a temporary memory and transmitted to the receiving station. At the receiving station, the received data block is decoded and reproduced in a form acceptable for human perception.
Translator I.M.Leonenko Editor O.V.Ivanova
2. G01S13/56,13/72
920728Vol. 1140 No. 4
Surveillance radar with a rotating antenna.
The surveillance radar contains a rotating antenna to obtain information about the range and azimuth of the detected object and an electro-optical sensor rotating around the axis of rotation of the antenna to obtain additional information about the parameters of the detected object. The antenna and sensor rotate asynchronously. A device is electrically connected to the antenna, which determines the azimuth, range and Doppler speed of detected objects with each rotation of the antenna. A device is connected to the electro-optical sensor, which determines the azimuth and elevation angle of the object with each rotation of the sensor. A common tracking unit is selectively connected to devices that determine the coordinates of an object, combining the received information and providing data to track the detected object.
2. Safety and environmental friendliness of the project
2.1. Safe organization of the PC engineer’s workplace
The fleet of personal electronic computers (PCs) and video display terminals (VDTs) based on cathode ray tubes (CRTs) is increasing significantly. Computers penetrate into all spheres of life in modern society and are used to receive, transmit and process information in production, medicine, banking and commercial structures, education, etc. Even when developing, creating and mastering new products, one cannot do without computers.
The workplace must provide measures to protect against possible exposure to hazardous and harmful production factors. The levels of these factors should not exceed the maximum values stipulated by legal, technical and sanitary standards. These regulatory documents oblige the creation of working conditions in the workplace in which the influence of dangerous and harmful factors on workers is either completely eliminated or is within acceptable limits.
2.2. Potentially dangerous and harmful production factors when working with PCs
The currently available set of developed organizational measures and technical means of protection, the accumulated experience of a number of computer centers (hereinafter referred to as CC) shows that it is possible to achieve significantly greater success in eliminating the impact of hazardous and harmful production factors on workers.
An occupational factor is called hazardous, the impact of which on a working person under certain conditions leads to injury or other sudden sharp deterioration in health. If a production factor leads to illness or decreased ability to work, then it is considered harmful. Depending on the level and duration of exposure, a harmful occupational factor can become dangerous.
The current state of working conditions for CC workers and its safety does not yet meet modern requirements. CC workers are exposed to such physically dangerous and harmful production factors as increased noise levels, elevated ambient temperatures, absence or insufficient illumination of the work area, electric current, static electricity and others.
Many CC employees are associated with the influence of such psychophysiological factors as mental overstrain, overstrain of visual and auditory analyzers, monotony of work, and emotional overload. The impact of these unfavorable factors leads to a decrease in performance caused by developing fatigue. The appearance and development of fatigue is associated with changes that occur during work in the central nervous system, with inhibitory processes in the cerebral cortex.
Medical examinations of CC workers showed that, in addition to reducing labor productivity, high noise levels lead to hearing impairment. Prolonged stay of a person in the area of combined exposure to various unfavorable factors can lead to occupational disease. An analysis of injuries among CC employees shows that most accidents occur from exposure to physically hazardous production factors when employees perform work unusual for them. In second place are cases associated with exposure to electric current.
2.3. Ensuring electrical safety when working with PCs.
Electric current is a hidden type of danger because... it is difficult to detect in current- and non-current-carrying parts of equipment that are good conductors of electricity. A current whose value exceeds 0.05A is considered fatally dangerous to human life. In order to prevent electric shock, only persons who have thoroughly studied the basic safety rules should be allowed to work.
Electrical installations, which include almost all PC equipment, pose a great potential danger to humans, since during operation or carrying out maintenance work a person can touch live parts. A specific danger of electrical installations is that live conductors that become energized as a result of damage (breakdown) of the insulation do not give any signals that warn a person about the danger. A person’s reaction to electric current occurs only when the latter flows through the human body. Of utmost importance for the prevention of electrical injuries is the correct organization of maintenance of existing electrical installations of the CC, carrying out repair, installation and preventive work.
In order to reduce the risk of electric shock, it is necessary to carry out a set of measures to improve the electrical safety of instruments, devices and premises associated with the process of design, production and operation of the device, in accordance with GOST 12.1.019-79* “Electrical safety. General requirements" . These activities are technical and organizational. For example, as technical measures, there may be the use of double insulation GOST 12.2.006-87*, and as organizational measures, there may be training, checking electrical equipment for serviceability, insulation quality, grounding, provision of first aid equipment, etc.
Electrostatic field(ESP) occurs due to the presence of electrostatic potential (accelerating voltage) on the display screen. In this case, a potential difference appears between the display screen and the PC user. The presence of ESP in the space around the PC leads, among other things, to the fact that dust from the air settles on the keyboard and then penetrates the pores on the fingers, causing skin diseases around the hands.
The ESP around the PC user depends not only on the fields created by the display, but also on the potential difference between the user and surrounding objects. This potential difference occurs when charged particles accumulate on the body as a result of walking on carpeted floors, clothing materials rubbing against each other, etc.
Modern display models have taken drastic measures to reduce the electrostatic potential of the screen. But you need to remember that display developers use various technical ways to fight with this fact, including the so-called compensation method, the peculiarity of which is that the reduction of the screen potential to the required standards is ensured only in the steady state of the display operation. Accordingly, such a display has an increased (tens of times more than the steady-state value) level of electrostatic potential of the screen for 20..30 seconds after it is turned on and up to several minutes after it is turned off, which is enough to electrify dust and nearby objects.
1. Measures and means of suppressing static electrification.
Measures to protect against static electricity are aimed at preventing the occurrence and accumulation of static electricity charges, creating conditions for the dispersion of charges and eliminating the danger of their harmful effects.
Elimination of the formation of significant static electricity is achieved using the following measures:
· Grounding of metal parts of production equipment;
· Increased surface and volume conductivity of dielectrics;
· Preventing the accumulation of significant static charges by installing special neutralizers in the electrical protection zone.
2.5 Ensuring electromagnetic safety
Most scientists believe that both short-term and long-term exposure to all types of radiation from a monitor screen is not dangerous to the health of personnel servicing computers. However, there is no comprehensive data regarding the danger of exposure to radiation from monitors for those working with computers, and research in this direction continues.
The permissible values of the parameters of non-ionizing electromagnetic radiation from a computer monitor are presented in table. 1.
The maximum level of X-ray radiation at the computer operator's workplace usually does not exceed 10 µrem/h, and the intensity of ultraviolet and infrared radiation from the monitor screen lies within 10...100 mW/m2.
Acceptable values of electromagnetic radiation parameters (in accordance with SanPiN 2.2.2.542-96)
Table 1
If the overall layout of the room is incorrect, the power supply network is not optimally laid out and the grounding loop is not optimally designed (although it satisfies all regulated electrical safety requirements), the room’s own electromagnetic background may turn out to be so strong that it is not possible to meet the SanPiN requirements for EMF levels at the workplaces of PC users. what tricks in organizing the workplace itself and not with any (even ultra-modern) computers. Moreover, the computers themselves, when placed in strong electromagnetic fields, become unstable in operation, and the effect of image shaking on monitor screens appears, significantly worsening their ergonomic characteristics.
The following can be formulated requirements, which must be used to guide the selection of premises to ensure a normal electromagnetic environment in them, as well as to ensure stable operation of the PC under electromagnetic background conditions:
1. The room must be removed from extraneous sources of EMF created by powerful electrical devices, electrical distribution panels, power supply cables with powerful energy consumers, radio transmitting devices, etc. If this option in choosing a room is not available, it is recommended that you first (before installing computer equipment) conduct a survey of the room according to level of low-frequency EMFs. The costs of subsequently ensuring stable operation of the PC in a room that is not optimally selected but given the criteria are incomparably higher than the cost of the survey.
2. If there are metal bars on the windows of the room, they must be grounded. As experience shows, failure to comply with this rule can lead to a sharp local increase in the field level at some point(s) in the room and to malfunctions of a computer accidentally installed at this point.
3. It is advisable to place group workplaces (characterized by significant crowding of computers and other office equipment) on the lower floors of the building. With such placement of workplaces, their impact on the overall electromagnetic environment in the building is minimal (energy-loaded power cables do not run throughout the building), and the overall electromagnetic background at workplaces with computer equipment is also significantly reduced (due to the minimum value of grounding resistance on the lower floors of buildings) .
At the same time, one can formulate a number of specific practical recommendations datsii, on organizing the workplace and placing computer equipment in the premises themselves, the implementation of which will certainly improve the electromagnetic environment and is much more likely to ensure certification of the workplace without taking any additional special measures for this:
The main sources of pulsed electromagnetic and electrostatic fields - the monitor and the PC system unit - must be located as far as possible from the user within the workplace.
There must be reliable grounding supplied directly to each workplace (use of extension cords with Euro sockets equipped with grounding contacts).
The option of one power line going around the entire perimeter of the workroom is extremely undesirable.
It is advisable to conduct power wires in shielding metal sheaths or pipes.
The user must be kept as far as possible from electrical outlets and power cables.
Fulfillment of the above requirements can ensure a tens and hundreds of times reduction in the overall electromagnetic background indoors and in workplaces.
2.6. Requirements for premises for PC operation.
The room with monitors and PCs must have natural and artificial lighting. Natural lighting should be provided through light openings oriented predominantly to the north and northeast to ensure a natural lighting coefficient (NLC) of no less than 1.2% in areas with stable snow cover and no less than 1.5% in the rest of the territory. The indicated KEO values are standardized for buildings located in the III light climatic zone.
The area per workplace with a VDT or PC for adult users must be at least 6.0 square meters. m., and the volume is not less than 20.0 cubic meters. m.
For interior decoration of rooms with monitors and PCs, diffusely reflective materials with a reflectance coefficient for the ceiling of 0.7 - 0.8 should be used; for walls - 0.5 - 0.6; for the floor - 0.3 - 0.5.
The floor surface in the operating rooms of monitors and PCs must be smooth, without potholes, non-slip, easy to clean and for wet cleaning, and have antistatic properties.
2.7. Microclimatic conditions
One of the necessary conditions for comfortable human activity is to ensure a favorable microclimate in the work area, which is determined by temperature, humidity, atmospheric pressure, and the intensity of radiation from heated surfaces. Microclimate has a significant impact on human functional activity and health.
In rooms with PCs, it is necessary to maintain optimal microclimatic conditions. They provide a general and local feeling of thermal comfort during an 8-hour working day with minimal stress on the thermoregulation mechanisms, do not cause deviations in health, and create the prerequisites for a high level of performance.
According to SanPin 2.2.4.548-96 “Hygienic requirements for the microclimate of industrial premises”, the optimal microclimatic conditions for premises during the warm season are:
Relative humidity 40-60%;
Air temperature 23-25 °C;
Air movement speed up to 0.1 m/s.
Optimal standards are achieved when using ventilation systems.
2.8. Noise and vibration requirements
When performing the main work on monitors and PCs (control rooms, operator rooms, control rooms, cabins and control stations, computer rooms, etc.) where engineering and technical workers work, carrying out laboratory, analytical or measurement control, the noise level should not exceed 60 dBA.
In the premises of computer operators (without displays), the noise level should not exceed 65 dBA.
At workplaces in rooms housing noisy computer units (ADC, printers, etc.), the noise level should not exceed 75 dBA.
Noisy equipment (ADC, printers, etc.), the noise levels of which exceed the standardized ones, should be located outside the room with a monitor and PC.
The noise level in rooms with monitors and PCs can be reduced by using sound-absorbing materials with maximum sound absorption coefficients in the frequency range 63 - 8000 Hz for finishing rooms (approved by the bodies and institutions of the State Sanitary and Epidemiological Supervision of Russia), confirmed by special acoustic calculations.
Additional sound absorption is provided by plain curtains made of thick fabric, harmonizing with the color of the walls and hung in a fold at a distance of 15 - 20 cm from the fence. The width of the curtain should be 2 times the width of the window.
2.9. Requirements for the organization and equipment of workstations with monitors and PCs
Workstations with VDT and PC in relation to lighting projects should be located so that natural light falls from the side, mainly from the left.
Layout diagrams for workstations with VDTs and PCs must take into account the distance between work tables with video monitors (towards the rear surface of one video monitor and the screen of another video monitor), which must be at least 2.0 m, and the distance between the side surfaces of video monitors - at least 1. 2 m.
Window openings in rooms where VDTs and PCs are used must be equipped with adjustable devices such as: blinds, curtains, external canopies, etc.
The video monitor screen should be at a distance of 600 - 700 mm, but not closer than 500 mm, taking into account alphanumeric characters and symbols.
Premises with VDTs and PCs must be equipped with a first aid kit and carbon dioxide fire extinguishers.
Layout of workplaces relative to light openings.
The purpose of the calculation is to determine the number and power of lamps required to provide sufficient illumination for the work of computer center (CC) personnel. Type of light sources - gas-discharge (low-pressure fluorescent lamps, shaped like a cylindrical tube), lamps - direct light. The lighting system is general, as it creates uniform lighting throughout the entire volume of the CC.
The brightness of general lighting lamps in the area of radiation angles from 50 to 90 degrees with the vertical in the longitudinal and transverse planes should be no more than 200 cd/m2, the protective angle of the lamps should be at least 40 degrees.
General lighting should be provided in the form of continuous or broken lines of lamps located on the side of the workstations, parallel to the user’s line of sight with a row arrangement of PCs and VDTs.
The lighting system is calculated using the luminous flux utilization factor method, which is expressed by the ratio of the luminous flux incident on the design surface to the total flux of all lamps. The room has two windows. Let's arrange the lamps in two rows parallel to the long side of the room, which has dimensions of 8 x 4 m and a height of 3 m. The lamps in the rows are located with a gap of 1.5 m, the distance between the rows is 1.5 m, and are installed on the ceiling. The height of the work stations is 0.75 m, so the calculated height h (the height of the lamps suspended above the work surface) will be 2.25 m.
Artificial lighting in rooms with a PC should be provided by a system of general uniform lighting. In accordance with SNiP 23-05-93, the illumination on the table surface in the area where the working document is placed from the general lighting system should be 300-500 lux. As light sources for general lighting, predominantly fluorescent lamps with a power of 35-65 W, type LB, should be used.
We find the luminous flux of a group of lamp lamps using the following formula:
=(*S**Z)/(N*) , (1)
where E n is the required standard level of illumination of the working surface. Let's take E norm = 300 lux - this is the most optimal value for a given room;
S = A*B = 8 * 4 = 32 m2 - room area;
k 3 = 1.5 - safety factor, taking into account the dustiness of lamps and wear of fluorescent lamps during operation, provided that the lamps are cleaned at least 4 times a year;
Z = 1.1 - illumination unevenness coefficient;
N is the number of lamps;
h- luminous flux utilization coefficient, selected from tables depending on the type of lamp, room size, reflection coefficients of walls r c and ceiling r p of the room, room indicator i ;
r p = 0.7 (surface color - white);
r с = 0.5 (surface color - light);
The number of lamps in the room can be determined by the following formula:
N=S/=32/=6.3(pcs).
Since the lamps are located in two rows, we choose their number even.
The room indicator can be determined by the formula:
i=(A*B)/((A+B)*h)=(8*4)/((8+4)*2.25)=1.18
Then, based on the values of r p, r c and i according to the table we select h = 0.42.
Fsv=(300*32*1.5*1.18)/(6*0.42)=6743 lm.
Considering that the lamp is designed for 4 lamps, we get:
Fd = Fsv/4 = 1686 lm - luminous flux of one lamp.
Based on the found luminous flux value, the type and power of the lamp can be determined. This value corresponds to an LD40 lamp with a power of 40 W and a luminous flux of 2100 lm. In practice, deviation of the luminous flux of the selected lamp from the calculated one is allowed up to ±20%, i.e. the lamp is selected correctly.
The lighting system uses 24 lamps of 40 W each. Thus, the total power consumption is:
P 0 = 24 * 40 = 960 W.
Considering that in such lamps power losses can be up to 25%, let's calculate the power reserve:
R p = 960 * 0.25 = 240 W.
Then the total network power should be:
P = P 0 * Pp = 960 +240 = 1200 W.
The layout of the lamps is shown in Fig. 1.
Thus, the general lighting system designed in this thesis project allows:
Ensure the possibility of normal human activity in conditions of absence or insufficient natural light;
Ensure the safety of vision;
Increase labor productivity and work safety;
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The PC is not hazardous to the environment. Radiation doses generated by PCs are small compared to radiation from other sources.
When computer technology operates, no environmental pollution occurs; therefore, no special measures are required to ensure environmental friendliness.
Based on the identified dangerous and harmful factors, as well as the considered methods of combating them, we can conclude that the project under consideration does not disturb the ecological balance in the surrounding area and can be used without any modifications or changes.
Conclusion
Currently, radar stations have found wide application in many areas of human activity. Modern technology makes it possible to accurately measure the coordinates of targets, monitor their movement, and determine not only the shapes of objects, but also the structure of their surface. Although radar technology was developed and developed primarily for military purposes, its advantages have led to numerous important applications of radar in the civilian fields of science and technology; the most important example is air traffic control.
With the help of radar in the process of air traffic control the following tasks are solved:
Detection and determination of aircraft coordinates
· Monitoring the adherence of aircraft crews to the lines of a given path, given corridors and the time of passing checkpoints, as well as preventing dangerous approaches of aircraft
· Assessment of weather conditions along the flight route
· Correcting the location of aircraft, transmitting on board information and instructions for launching to a given point in space.
Modern ATC radars use the latest advances in science and technology. The elemental base of radars are integrated circuits. They widely use elements of computer technology and, in particular, microprocessors, which serve as the basis for the technical implementation of adaptive systems for processing radar signals.
In addition, other features of these radars include:
· Application of a digital SDC system with two quadrature channels and double or triple subtraction, providing a coefficient of suppression of interference from local objects up to 40..45 dB and a coefficient of sub-interference visibility up to 28..32 dB;
· The use of a variable repetition period of the probing signal to combat interference from targets distant from the radar at a distance exceeding the maximum range of the radar, and to combat “blind” speeds;
· Ensuring linear amplitude characteristics of the receiving path up to the input of the SDC system with a dynamic range of the input signal up to 90..110 dB and a dynamic range of the SDC system equal to 40 dB;
· Increasing the phase stability of the generator devices of the radar receiver and transmitter and the use of a truly coherent principle of radar construction;
· Application of automatic control of the position of the lower edge of the radar viewing area in the vertical plane due to the use of a two-beam antenna pattern and the formation of a weighted sum of the signals of the upper and lower beams.
The development of air traffic control radars is characterized primarily by the tendency to continuously increase the radar's noise immunity, taking into account possible changes in the interference environment. Increased radar accuracy is achieved mainly through the use of more advanced information processing algorithms. Increased reliability of the radar is achieved through the widespread use of integrated circuits and a significant increase in the reliability of mechanical components (antenna, rotating bearing and rotating transition), as well as through the use of equipment for built-in automatic control of radar parameters.
Bibliography
1. Bakulev P.A. Radar systems. - M.,: Radio engineering, 2004.
2. Radzievsky V.G., Sirota A.A. Theoretical foundations of electronic intelligence. - M.,: Radio engineering, 2004.
3. Perunov Yu.M., Fomichev K.I., Yudin L.M. Electronic suppression of information channels of weapon control systems. – M.: Radio engineering, 2003.
4. Koshelev V.I. Theoretical foundations of electronic warfare. - Lecture notes.
5. Fundamentals of system design of radar systems and devices: Guidelines for course design in the discipline “Fundamentals of the theory of radio engineering systems” / Ryazan. state radio engineering academic; Comp.: V.I. Koshelev, V.A. Fedorov, N.D. Shestakov. Ryazan, 1995. 60 p.
