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Weapons of Mass Destruction (WMD)

Cat House Dunay-3U
5510'N 3713'E

The Moscow A-35 anti-ballistic missile system included the Dunay-3 (chief designer V.P. Sosulnikov) and the improved Dunay-3U (chief designer A.N. Musatov) sector radars, known in the west as DOG HOUSE and CAT HOUSE. A total of eight Dunay sector radars were originally planned, but by 1971 only four of the Dunay sector radars had been built. At that time a decision was made to finish building the facilities already started at the second Dunay-3U radar, and to halt the rest of the work.

Danube-3U was part of the A-35M long-range anti-missile system. The system is closed, the platform with the receiving antenna is abandoned. Chief Designer was A.N.Musatov. It was put into operation in 1978 together with the adoption of the A-35M system. It was built in Chekhov-7 near the railway platform Chernetskoe Bolshoi ring of the Moscow railway (the district of Chekhov, in the south of the Moscow region). During the development and creation of the station, the experience of designing and operating the Dunaj-3M station was taken into account, as well as a number of new technical solutions related to significant technological progress in electronics that occurred over the years since the previous modification was developed. This allowed increasing the range and accuracy of the station, the reliability of its operation.

In 1979 the United States began planning to station 108 new Pershing-2 medium-range ballistic missiles in Germany. The Pershing-2's flight time to Moscow was only 10-12 minutes, posing a possibility of surprise destruction of hardened command and control facilities. the Dunay-3U long-range detection radar, oriented to the west, was capable of detect the launch of Pershing-2 missiles no later than 2-3 minutes after launch from the northern and central part of Germany [the southern part of German territory was not monitored by the radar at extremely low angles].

In the early 1980's due to the planned deployment of American Pershing-2 missiles in Western Europe, the Dunai-3U radars were upgraded for broadening of their surveillance sector aimed at covering West German territory. Modification of the radar transceivers, increasing their power, made it possible to expand the search sector and reliably cover the entire territory of Germany. It was decided to modify the transceivers and combat program of the radar, taking additional steps for fire safety, and the radar was modified in a short time with minimal costs.

Novo-Gromovo      PPL   5516'00"N   3714'00"E 
Chekhov           PPL   5508'53"N   3728'37"E  [DOD]
Stremilovo        PPL   5508'43"N   3709'10"E  [NIMA]
Stremilovo        PPL   5510'   N   3711'   E  [Zaloga]

The Cat House radar is normally reported as being located near Chekhov [5508'53"N 3728'37"E], approximately 65 km (40 mi; 35 nm) southwest of Moscow. 3aloga reports that the Cat House radar is located at Stremilovo, but provides coordinates [5510'N 3711'E] that are somewhat different from those provided for this placename by NIMA [5508'43"N 3709'10"E]. In fact, it appears that the radar complex is slightly to the east of both these sets of coordinates, and is located at 5513'12"N 3717'24"E, near Novo-Gromovo [which is located at 5516'00"N 3714'00"E .

Cat House Dunay-3U

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The creation of radio technical units for early detection was accompanied in the 1960-1970's. with considerable difficulties. In particular, in those days in the USSR there were no powerful broadband with a large gain factor and a long service life of the vacuum devices. There were electrovacuum demountable pumping devices with a power of no more than 50 kW, with a gain of about three, a period of operation of about 400 hours and a recovery time of about two days. This was frankly little. Therefore, the designers decided to develop sealed traveling wave tubes (TWT) for a power of at least 100 kW, an amplification factor of at least 1000, an efficiency of at least 30%, an inclusion time of no more than 10-15 minutes and a service life of several years. And this problem was successfully solved - the designed TWT was named "Spring".

Further. The then existing air defense radar, using mirror antennas with a relatively small opening area and mechanically moving the antenna pattern for space review (sequential review), proved to be unsuitable for work on new targets. Required antennas with a larger opening surface, with a greater speed of space survey, which is possible with electric swing of a DV with parallel-sequential view or with a parallel survey of a given solid angle of space.

In the 1950-60s the technology of manufacturing phase shifters for phased antenna arrays had not yet been sufficiently worked out, but methods of rocking the beam by changing the frequency in linear antenna arrays of a traveling wave have been mastered. In this connection, active antenna arrays of linear traveling-wave radiators with parallel-sequential space survey were used in the first stations of the early detection of ballistic missiles. Stations with such antennas provide the required speed of the survey of space and target ranges of target detection.

After the creation of a number of radars using antennas with frequency swinging, it became possible to use phased antenna arrays with a fully phase oscillating of the disks by means of discrete switching phase shifters. Further development of radar technology was associated with the development of a radar with a digital method of generating NAM for reception and parallel-sequential, and when working on promising targets - with a parallel view of the space.

During the creation of the "Danube-3U" the Soviet Union simply did not have powerful computing tools. In particular, there was a computer BESM-6 with a capacity of approximately 180 thousand algorithmic operations per second. And to maintain the created radar required a computer with a capacity of at least 200 million such operations per second. Therefore, in connection with the limited performance of computers at that time, the question arose how to build a calculator for processing information, control and functional control, how to distribute goals between individual machines and how to ensure the safety of information about the escorted targets in the event of a failure of any calculator, and also much more.

In general, an analysis of the problems that have arisen has shown that an absolutely new approach to the construction of radio-information means for rocket and space defense is needed. In order to solve these problems, a radically new approach to the construction of a radar as a single specialized information system was approved, in which the computational means are functional nodes of the station and are developed simultaneously and in direct connection with the development of radar equipment of the radar station on a unified engineering and technological basis, on unified engineering solutions under the supervision of the Chief Designer of the radar station.

This approach allowed the most rational distribution of information processing functions between various functional nodes of the station and ensure their interaction, choose the architecture of the computer system and its components that are most appropriate for the radar problems and the conditions for realizing them in real time. This allowed providing unique technical and technical and economic characteristics of the "Danube-3U" radar, including its unrivaled till now its capacity in terms of the number of space objects served and complex ballistic targets.

For simultaneous detection of thousands of targets, calculating coordinates and constructing the trajectories of space objects, a queuing system was needed that had as its basis a receiving measuring device with high sensitivity, with a digital output, unlimited bandwidth, high accuracy in measuring the coordinates of space objects, and high reliability.

Algorithms and programs must ensure the automatic execution of all processes: detection, trajectory construction, classification of space objects, management, functional control and redundancy. In addition, it was required to ensure high reliability of the radar - at least 105 and the probability of false alarms - no more than 10-5. It was necessary to develop and new principles of aligning the radar. The complex radar model should provide a radar check when simulating a raid of 30 complex ballistic targets with a set of 32 elements.

Among other things, it was necessary to investigate the real characteristics of complex combat targets at various sections of the trajectory (active site, extra-atmospheric flight, entry into the dense layers of the atmosphere, to study the possibility of deploying anti-missiles in a single radar field). Finally, it was required to minimize the cost and timing of the station.

Analyzing the problems listed above, the team of developers (headed by the chief designer of the Dunay-3U radar Alexander Nikolayevich Musatov) came to the conclusion that for the successful implementation of the Danube-3u radar project it is necessary to create an experimental radar station "Danube-3UP". The Ministry of Defense, the Ministry of Radio Industry and the Military Industrial Commission supported the proposal of designers. At the 10th State Research Area (Sary-Shagan), and such a radar was created. In fact, it was a shortened version of the radar "Danube-3U."

Radar station "Danube-3UP". The "Danube-3UP" radar was an early warning radar with high capacity, capable of operating for complex ballistic purposes. The high quality of development of design documentation allowed to agree a complete set of technical documentation with the Ministry of Defense and issue equipment to cooperative plants with military acceptance, successfully carry out design (factory) and State tests.

This became possible thanks to a very strong thematic and branch team of like-minded people and enthusiasts and high-tech manufacturing plants of cooperation.

Introducing this procedure for creating a radar, the developers pursued the following objectives: to check the principles of constructing the radar "Danube-3U"; to develop technical documentation on the radar "Danube-3U" at a high level; to offer "Danube-3UP" as an inexpensive long-range radar with characteristics exceeding the characteristics of all existing radar stations, having independent significance or rendered to the borders of the USSR.

However, at the final stage of the State tests, before the signing of the act by the State Commission, the customer, represented by the 4th GU MO (M. G. Mymrin and M. I. Nenashev), crossed out on the title page of the Technical Conditions "Technical conditions for the Danube-3UP radar station and recorded (against the will of the developer) "Installed technical specifications on the radar" Danube-3UP ". So with one stroke of the pen, the Ministry of Defense closed the road for independent use of the best at that time in the world inexpensive radar "Danube-3UP". There are no "technical conditions" - hence, there is no technical documentation. And there is no radar.

Only one example. According to the terms of the SALT agreement, it was impossible to install a radar of the type "Daryal" in the vicinity of Yeniseysk. The decision was made to install radar "Danube-3UP" in the Norilsk area with more opportunities (the cost of construction was ten times cheaper than the construction of the Daryal type radar). However, this decision was canceled. Under the city of Yeniseisk, the radar "Daryal" and the town were built, which, at the request of the Americans, were later demolished.

"Danube-3U" is a radar of continuous radiation with linear frequency modulation. The station is located on two positions, spaced from each other by about three kilometers - the transmission and reception. However, both positions are designed as a single queuing system managed by an automatic control system (ACS).

"Danube-3U" is characterized by the following characteristics. The rate of the review of space is 4 seconds, the line-by-line type of television raster. The first line is every second, the second line in two seconds, the remaining 14 lines in four seconds. The sector of the survey of the space along the azimuth and the elevation angle 48 by 48 . The design range of detection of ballistic targets is not less than 5 thousand km. The minimum elevation angle is 0.5 .

Emitted power in continuous mode - 3 thousand kW. The sensitivity of the receiving device is 10-18 W. The radar makes it possible to automatically detect and construct the trajectories of space objects, as well as their classification (satellites, combat missiles attacking the central industrial area - BR1, attacking the USSR (Russia) - BR2). "Danube-3U" allows you to determine the nature of the raid (single target, SBC, group raid, massive raid). The capacity of the radio-technical tract is unlimited. The capacity of the computer complex is characterized by the ability to construct at least 1,000 trajectories of space objects (32 complex ballistic targets) simultaneously. The maximum errors in measuring the coordinates are: in range - no more than 100 m, in azimuth - no more than 5 angular minutes, in elevation - no more than 7 angular minutes.

The radar "Danube-3U" provides automatic control, automatic functional control of all equipment and redundancy. The restoration of the equipment is carried out on the "Danube-3U" as follows. Access to the equipment of the special recovery group only after the call and authorization of the automatic control system - with automatic unlocking of the lock of the cabinets. After restoration - automatic checking of the parameters of the refurbished ACS equipment.

Transmitting position. Composition: antenna, transmitter, synchronization system, power system and cooling system. Antenna cloth has 30 waveguides. Each waveguide is excited from a separate 100 kW transmitter that generates a pure signal without parasitic oscillations, with low intrinsic noise, no more than 10-18 W / Hz per watt of radiated power at range frequencies and with precision parabolic phase modulation (LFM). Structurally, the transmitting and receiving antennas are constructed on identical waveguides with a half-wave retardation structure and decoupling elements between the waveguides. The half-wave retardation structure in the case of the emission of oscillations with a chirp shifts the linear ray along the azimuth. Decoupling is introduced to eliminate the coupling between waveguides and ensure the stability of the antenna antenna in the azimuth plane and the independence of the phase distribution in the angle plane.

The required amplitude and phase distribution along the waveguides are provided by the design of the waveguides and their high accuracy. The slope of the phase front in the elevation plane is set from the automatic control system and monitored by automatic phase systems (SUF) by comparing the phases of oscillations of waveguides taken from the centers with oscillation phases from the reference path. This allowed to create a review of the space by the type of a television raster, due to the emission of a frequency-dependent antenna of oscillations with a chirp in the azimuth plane and phase control in the angle plane.

The maximum radiated power in the decimeter wave band in continuous mode is 3 thousand KW is achieved by adding power from 30 elementary transmitters with a capacity of 100 kW. Each transmitter includes an exciter with a power of 50 W and a powerful amplifier on the TWT "Vesna" with a power of 100 kW. The exciters' generators that are tuned by ferrite are controlled by automatic phase systems which, by comparison of the phase shifts of waveguides taken from the centers with oscillation phases from the reference path, change the oscillation phases of the oscillators according to a given parabolic law on special sensitive elements.

The radar synchronizer had two modes: stand-alone, in which the reference oscillations are generated by a quartz oscillator and external, from the single-time (CEV) service. Synchronizing pulses are stabilized in the same way as in chirp forming systems. The distribution for consumers is made by special devices and impulse cables. The input resistance of the consumers is matched with the wave resistance of the impulse cables. This achieves high accuracy and reliability of radar synchronization. So, for example, all 30 elementary transmitters start simultaneously in time with an accuracy of 5 nanoseconds.

The power supply of the radar is provided by three independent high-voltage power lines. The substation and switchgears are located near the transmitting position. Powerful power equipment: power transformers, high-voltage rectifiers KVTM for TWT "Vesna", are outside the premises and do not require constant maintenance. This allowed to reduce the size of buildings and the capacity of cooling systems. Such a project ensured high reliability and durability of the equipment, which is confirmed by more than 30 years of accident-free operation of this equipment.

The cooling system is a water dual circuit. The external circuit removes heat from buildings, removing heat from boilers and refrigeration machines, specially prepared artesian water through the cooling towers. The internal circuit removes heat from the equipment with water cooled boilers and refrigerating machines.

The receiving position includes: a receiving antenna, a receiving device, an associative information distribution system (ARPI), a central computer (CVS), an automatic control system (ACS) of the entire radar, a cooling system and an engineering complex. The receiving antenna forms a DNA in the azimuth plane of 0.5 and in the azimuth plane - 0.75 . Antenna cloth consists of 100 same waveguides, as well as on the transmitting position. The queuing system provides automatic detection of all space objects in the survey sector, construction of single and SBC trajectories, distribution of them along the machines of the CVS, classification and storage of the parameters of the escorted objects in the ACS.

Composition of the computer complex system of associative information distribution (ARPI), the central calculator (CVS) on seven special computers K340 and the automatic control system of the radar on three K340 machines.

The Duna-3U-61 was put into operation in May 1978 with a fixed service life of 12 years (expired in May 1990). Then the service life of the SLLS-1 and the SLLS-2 was prolonged until January 1, 2001. Then the service life of the SLLS-61 was prolonged until January 1, 2005. In 2005 the service life of the SLLS-61 was prolonged until December 31, 2009. Thus , The SLLS-61 has been continuously operating in the "combat operation" mode since May 1978. Since February, 2003 the station was operated with a reduced set of elementary transmitters K22PE and a reduced radiation power (of the 30 transmitters in the BR mode, there are currently 12 (with a set of not less than 24) .The total radiation power is less than 500 kW instead of 1800 kW (according to manual).

SRLS-62 was put into operation in May 1978 with a fixed service life of 12 years (expired in May 1990 and extended to 2000). Since September 1998, the FRA-62 was in the "off" mode. Thus, during the alert, both radars "Danube-3U" showed high tactical and technical characteristics and reliability indicators. In the combat alert mode, long-range ballistic missile radars are mainly detected and escorted by space objects such as satellites. The role of the radar "Danube-3U" (and including the SLLS-62 - before shutdown) in maintaining the catalog of space objects, it is necessary to emphasize especially, the key one.

Both radars during the database detected and accompanied various space objects on the instructions of higher authorities. Due to the high accuracy in determining the coordinates of targets, the radar "Danube-3U" was constantly involved in identifying the coordinates of the fall of especially important domestic as well as foreign combustible satellites (including the "Danube-3U" followed the space station "Mir" during the descent her from the orbit).

The western radar "Danube-3U" showed its high performance when working on small-sized targets (with EPR - 0,017 sq. M.), Released from the ship "Shuttle". All targets were detected at maximum range and were followed until the exit from the station's responsibility sector. The information was transmitted to the higher CP. The radar successfully participated in the military-space experiment using the 11F634 spacecraft of the Typhoon missile and space complex.

In the period from 1978 to 1998, the SLLS-62 carried out the postings of ballistic missiles and satellite launches along the Kapustin Yar-Balkhash, Kapustin Yar-Aralsk-Emba, Aralsk-Kamchatka, Aralsk-Tomsk, Saratov-Kamchatka and satellite launches. In total during this time, more than 700 postings of experimental ballistic simple and complex targets and satellite launches were carried out.

The "Danube-3U" radar makes the main contribution to the solution of the tasks of the PSC, in particular, the main task is to maintain the catalog of space objects (QRs) in the orbits of the satellite in the low-orbital region (height above the surface of the Earth under observation of less than 3.5 thousand km).

As of 1995, this contribution was characterized by the following data. From SRLS-61 and 62 received 50% of the results of all radar measurements (about 20 thousand measurements per day). SRLS-61 and 62 participated in the control of 98% of all escorted objects of the catalog. 50% of all low-orbit objects in the catalog (about 2.5 thousand) were monitored mainly according to the information of the FSRS-61 and 62. Among the measurements involved in the detection of new KOs, about 90% are measurements from the Dunay-3u radar. When KO was destroyed, most of the fragments (with an effective scattering surface of more than 0.01 sq. M) were detected by the radar "Danube-3U".

The key role of the radar "Danube-3U" in solving the problems of the PSC is determined by the following reasons. The radar "Danube-3U" (in contrast to the radar "Dnepr" and "Daryal") operates in the decimeter range of radio waves. This allows, in principle, to obtain measurements on objects of size from 15 cm to 40 cm, which are practically inaccessible for observation in the radar meter range ("Dnepr" and "Daryal"). There are more than half of such space objects in the American catalog.

The main mode of operation of the "Danube-3Y" radar is a line-by-line review of the entire responsibility sector, i.e., the FRA produces a QoS detection in the entire sector. This creates significant advantages over other high-potential radars when working on small satellites (in particular, in front of the Daryal radar, which detects QoS only in a fairly narrow barrier zone).

Two Danube-3 (Kubinka) stations have been dismantled from the created Danube-3 military radar stations, the Danube-3U (SRLS-61) is on alert duty, SRLS-62 is off. That is, a station with high capabilities to provide information to the space monitoring system is idle and gradually deteriorates. At the same time, our space monitoring system is not sufficiently provided with radar facilities for obtaining information on space objects.

The construction of a new station with the characteristics of the radar "Danube-3U" (the area of the receiving antenna of 5 thousand square meters, the radiated power of 2 MW based on the phase-phase rocking of the antenna array) is not currently possible due to the very high cost of the project an order of magnitude higher than the cost of upgrading the radar "Danube-3U"). However, this task is easily solved by the modernization of the radar "Danube-3U". In connection with this, it is proposed to create specialized radar stations of the comic space monitoring system for detection and control of small-size space objects by upgrading the Danube-3U radar.

Modernization is proposed to be carried out with a wide use of the scientific and technical reserve obtained when creating a radar of high factory readiness type DM in terms of hardware solutions, the use of the newest element base (semiconductor devices, FPGAs, microchips) and software implementation of control and monitoring processes, as well as adaptation to Changes in the space (including interference) environment.

Confidence in the possibility of creating a product when implementing the below proposed characteristics is determined by the availability of cooperation, which includes both the suppliers of the element base and the manufacturers of radioelectronic equipment units.

The offered radar stations are the further development of the radar for the early detection of ballistic missiles and space objects "Danube-3U". The swing of ND in these stations is made by changing the frequency of the emitted (received) signal by azimuth and the phase method by the elevation angle. Stations operate in continuous radiation mode: they simultaneously emit microwave energy, sequentially exposing a given sector of space, and taking energy reflected from targets. To ensure the required amount of decoupling between the transmitting and receiving paths, the stations are located at two positions-the transmitting and receiving stations.

Overview of the space line by type of television raster. The beam movement along the azimuth (line) occurs due to a linear change in the frequency of the radiated signal, in connection with which the antenna is made of linear radiators of the traveling wave. The position of the NAM with respect to the elevation angle is determined by the phase distribution between the linear emitters.

The range of the radar for a given target depends on the speed of the survey of space (rate of change of frequency). By changing the frequency, the rate of change in frequency and the position of the NAM by elevation angle can be detected to accompany the target and examine their characteristics in any subsector of the radar's coverage area.

In the stations of this type there are no losses due to the arrangement of the receiving DNs in the azimuth, since the reflected signal is formed due to the motion of the LV in the azimuth and the direction to the target passes the maximum of the diagram.

In stations of this type, there is also minimal time loss for waiting for reflected signals - only at the end of each line.

An important advantage of the stations is the low level of the residues of the "compressed" received signal. This is due to the methods of forming and processing the received signals. The formation of the reflected received signals occurs automatically when the targets intersect with the moving antennas of the receiving and transmitting antennas. That is, the form of the received signal coincides with the form of the product of the transmitting and receiving antennas. Directional patterns and their products are entire functions of exponential type and have a limited spectrum, i.e. after spectral processing the values of the spectral components, other than zero values, will appear only on a finite frequency interval. Almost in the radar "Danube-3U" the level of residues does not exceed 80 dB. Advantages: no need to create a new object; no capital construction is required; the main devices of the station: the transmitting antenna-feeder device, the receiving antenna-feeder device and the transmitting device are installed, are in working order and only require further development to meet the additional requirements for the radar.

Characteristics of the radar. The range of action: in azimuth - from 71.5 to 123.5 degrees. and from 255.5 to 281.5 degrees; on the elevation from 1 to 49 degrees. In the range from 100 to 6 thousand km in the regime of the coverage of the coverage zone with respect to the angular coordinates.

Specifications. The frequency range is 388-429 MHz; CPD AFU for transmission - 34 thousand, the width of the directivity pattern: 36 minutes in azimuth and 3 degrees. on a corner of a place on transfer, 36 mines and 1 hailstones on reception. The average power at the input of the AFU is 1.2 to 106 watts. The temperature of the noise of the receiving path, reduced to the input of the antenna amplifier, is 285 deg. by Kelvin. The area of the receiving antenna is 5 thousand square meters. The total loss is 7 dB.

The first results of modernization are exemplified by the example of the western station (SRLS-61). Modernization of the western station (object 0746) began in 2003. The purpose of modernization is to create a radar with higher characteristics than the radar "Danube-3U" (and the extension of the station's resource). In 2008, low-noise amplifiers of the receiving antenna were replaced. As a result, the noise temperature of the receiving path decreased by more than 2 times, which led to a corresponding increase in the station potential and, consequently, to an increase in the number of detectable and escorted space objects. Before replacing the antenna amplifiers, the "Danube-3U" station provided information on 400 low-orbiting space objects, after the replacement of amplifiers - 3.1 thousand.

Operating continuously for more than three decades, the Dunay-3U radar is still one of the most important information facilities of the Russian Navy and fulfills the tasks set for controlling the airspace in the interests of Russia's national security. The operation of the Dunay-3U FMS showed its high reliability, stability and durability, as well as a wide range of adaptability in building up combat capabilities. With the development of means of aerospace attack, the station has been repeatedly refined and continues to be one of the key elements of rocket and space defense. The "Danube-3U" survived the A-35 ABM system, then the A-35M, which was replaced by the more modern A-135 system.

By its characteristics and the period of operation, the sector radar in Chekhov near Moscow is still one of the notable phenomena not only in the domestic, but also in the world.

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