P-15 (Flat Face)
The P-15 Tropa ( Russian П-15 Тропа , German way, path ) is a Soviet radar device for the reconnaissance of low-flying air targets and target assignment. It was introduced into the armament of the Soviet Army in 1955 . The default name is 1РЛ13 ( transcription : 1RL13) which NATO Code Name Flat Face A .
The radio technical troops of the NVA designated the radio measuring station with P-15 or for reasons of secrecy with 03 . In the Army Air Defense (NVA) the system was also called Rundblickstation 15 , abbreviated as RBS-15 .
development
Development of the P-15 began in 1952 at the Research Institute NII-244 (НИИ-244) of the Ministry of Defense of the Soviet Union. The aim was the development of a radar device for clearing up low-flying targets. Compared to the radar stations P-8 and P-10, the accuracy and tactical flexibility should be increased. The development of the P-8 and the P-10 ultimately goes back to the British Light Warning Radar AA No 4 Mark II and Mark III supplied by Great Britain during the Second World War under the Lend-Lease Act . The 30 units delivered were designated as ORL-4 ( OРЛ-4 ) in the Soviet Army . The radar stations Most-2 and P-5, introduced in 1946, were created on this basis . Also introduced in 1946 was the P-3 radar station , which was based on the RUS-2 developed by the Soviets . From the P-3 and the P-5 , the P-8 finally emerged in 1948 and finally the P-10 around 1950 . All of these radars are pulse radars that operate in the VHF range. The frequency range required a relatively large antenna system, which was designed as a group antenna with individual Yagi antennas. This made construction complicated and tedious, resulting in poor tactical maneuverability. However, since the dimensions of the antenna system could not be chosen arbitrarily large, the accuracy of the angle determination and the resolution of the side or elevation angle were relatively low. With the transition to the UHF range, these disadvantages were largely eliminated. All components of the station, including the antenna system, could be accommodated on an all- terrain truck SiL-157 and a single-axle trailer.
In parallel to the P-15 , the Topol-2 ( Topol-2 ) radar station was developed in the NII-244 . With a reconnaissance range of around 150 km, this radar station should have an even higher resolution and accuracy than the P-15 . This was made possible by using frequencies in the cm range. The radar station went through state testing, but was ultimately rejected by the leadership of the Soviet Army.
The P-15 , however, was able to successfully complete state testing in 1955 and was then taken over into the armament of the Soviet Army. It was used by the air defense troops, the land forces, but also the Soviet naval fleet. The radar device was continuously modified. The P-15M tested in 1959, the P-15N tested in 1962 and finally the P-15MN released in 1970 , which eventually led to the P-19 , were major milestones in development . The latter replaced the P-15 in service with the Soviet Army and other armed forces.
As a high level of tactical mobility was not absolutely necessary for the air defense troops, the P-15M2 version was mostly used here. The antenna system was mounted here on a remote mast. This configuration received the NATO code Squad Eye .
construction
Construction of the radar station
The system consists of
- the equipment vehicle with box body on ZIL-157
- the identification device NRS-15
- the trailer TAPZ-755 B or 1-AP-1,5 B
- two electric units AB-8-0 / 230 / Tsch-425
- Accessories and spare parts.
Basic interaction of the elements of the weapon system
The box body contained the electronic assemblies, the antenna system and the operator workstations. In the marching position, the lattice mast was folded back. The middle segments of the antennas rested on the roof of the box body, the side segments were folded down. For rail transport, the side segments were removed and attached to the side of the single-axle trailer. A maximum of 17 minutes was required to set up the system, plus another 3.5 minutes to switch on the system. This time was due to the need to preheat the electronic assemblies. The electrical units carried on board were used for the power supply, one unit was loaded on the truck, the second was on the single-axle trailer.
Recognized air targets were displayed on a 2D panoramic device. To determine the height, the system had to be coupled with so-called height finders such as the PRW-10 . The reconnaissance air targets were identified with the help of the integrated identification device NRS-15 . The P-19 could also be used with the automated fire control complex 9S44 “Krab” .
In order to increase the immunity to interference and the reconnaissance range, the P-15 was usually used with other radar stations. This was also necessary because a reconnaissance of high-flying air targets with the P-15 was technologically not possible. The P-12 or P-18 operating in the meter wave range were regularly used . With the help of the above-mentioned radar stations, above all higher-flying air targets could be detected. The frequency range used also facilitates the reconnaissance of air targets with stealth properties. The reconnaissance results of the various radar devices were summarized and displayed on the viewing devices of the automated fire control complex.
The operation consists of a total of five soldiers. This makes it possible to work in shifts, as only two to three soldiers are required at the same time to operate the station.
Carrier vehicle, cabin and power supply
The all-terrain truck ZIL-157 was used as the carrier vehicle. The system could be installed on roads as well as in the field. However, due to the heavy structure with a high center of gravity and the sensitive electronic assemblies, a maximum speed of 10 km / h was not allowed to be exceeded in the field, on the road a cruising speed of 40 km / h was permitted. The vehicle had a length of 7.3 m (10.6 m with trailer), a width of 3.1 m and a height (in a marching position) of 4.0 m. The total weight was 9.2 t. The case contained the electronic assemblies, the telecommunications equipment and the operator's workstations. While the first versions were still equipped with an oven heater, the OW-65 heating and ventilation system was used from version P-15M1 . It enabled the suitcase to be heated and ventilated even when the vehicle was stationary, regardless of whether the vehicle engine was running.
An independent navigation system was not available. To determine the exact position, the position had to be measured with the aid of the associated alignment circle / theodolite PAB-2 with the aid of known and measured points in the area.
The power consumption of the entire system is around 7.5 kW. The two AB-8-0 / 230-Tsch-425 electrical units , which provide three-phase alternating current with a mains frequency of 425 Hz and a voltage of 3 × 230 volts, are used for power supply . Each unit can generate up to 8 kW.
Antenna system
The antenna system consisted of two cut parabolic mirrors . This design as two paraboloids of revolution placed one above the other resulted in a relatively high resolution in the horizontal plane, but only a low one in the vertical plane. These antennas were fed by two horn antennas . In front of the upper horn antenna there is an additional "guide plate" installed to form the directional diagram (which was often "forgotten" during alarm exercises because of the time pressure). (Incidentally, most of the museums where the P-15 is exhibited today have the same “problem”.) The feed could be in phase as well as in phase, which changed the shape of the directional diagram. The antenna system is mounted on a lattice mast, which can be folded back in a marching position. During operation, the mast rotates at 6 / min in the horizontal plane, in the vertical plane the antenna system cannot be swiveled, so it is not possible to determine the flight altitude of the aerial target. By switching the feed of the two parabolic antennas, however, an air target can be assigned to one of a total of three altitude sectors. Due to the directional characteristics of the antenna, aerial targets at an altitude of over 5 km cannot be detected.
The antenna system determines the accuracy of the determination of the side angle and the resolution . The side angle could be determined with an accuracy of 2 °, the resolution was 8 °. In practice, this means that all aerial targets that were at approximately the same distance in a sector each 8 ° wide were shown on the viewing devices as one aerial target.
In order to improve the reconnaissance possibilities against low-flying air targets, an intermediate piece can be used to raise the antenna. However, the use of the intermediate piece increases the time required for assembly and dismantling, since the mast can no longer simply be folded down in the marching position. The AMU-15 or AMU-30 mast, which had to be erected separately, was also available for use by the air force . The use of the mast again increased the time for erection and dismantling, but the greater height of the antenna above the surface of up to 50 m also improved the reconnaissance possibilities against low-flying targets.
Radar device
The radar device works in the UHF range with a transmission frequency in the range of approx. 830 MHz. A magnetron is used in the transmitter of the radar device . The transmitter generates pulses with a length of 1.5 μs and a pulse power of 270… 300 kW. The pulse repetition frequency is 500… 660 Hz. This means that the inclined distance to the air target can be determined with an accuracy of 900 m, the resolution is given as 2500 m. In practice, this means that all aerial targets that are in the same direction in a 2500 m deep section could not be recognized as two objects on the viewing devices.
To protect against active radar interference, the transmission frequency could be quickly switched between four preset frequencies.
The receiver has a sensitivity of 2 × 10 −14 W. A traveling wave tube was used in the receiver . The interference protection systems were continuously revised. A system for selecting moving targets (SBZ) was in place to protect against passive disruptive measures ( chaff ) . While this system was built with delay lines in the first versions , potential storage tubes were used in later versions .
The air situation was shown on the panoramic device in the box body. The situation report was updated every ten seconds. The result of the identification query was also shown on the display devices. The ID device NRS-15 integrated in the station for ID query is part of the friend-foe ID system Kremnij 2 .
The radar system was able to detect aircraft at an altitude of 50… 5000 m at a distance of up to 200 km. The detection distance depends to a large extent on the radar cross-section and the flight altitude of the targets and, especially in the case of low-flying targets, on the terrain profile and the location of the radar device. Air targets at an altitude of 500 m can be detected up to a distance of 70 km, at an altitude of 5000 m up to 190 km. These values apply to air targets with the approximate size of an Il-28 bomber plane . In the reconnaissance of low-flying targets, the height of the antenna above the surrounding earth's surface was decisive. An aerial target with an altitude of 15 m could be cleared up to 18 km if the radar station was on level ground. When using the intermediate piece in the antenna mast or the mast AMU-27 , the range for such a low-flying target could be increased to 20 ... 28 km, when the station was set up on a hill 100 m above ground it was 43 km, at a cant of 300 m even at 84 km.
The P-15 could also be used with the automated fire control complex 9S44 “Krab” . To do this, the P-15 was wired to the 9S416 KBU fire control cabin (Russian: кабины боевого управления) of the 9S44 complex . Several radar devices could be connected to the fire control cabin, but only the information from one radar device could be displayed on the display devices, and switching between the display of the individual connected radar systems was done manually.
Modifications
The P-15 was continuously developed during its production time.
P-15M
The P-15M version was tested in 1959 and then introduced. This version made it possible for the first time to couple it with the automated fire control complex 9S44 “Krab” . In the system for the selection of moving targets, the transit time chains based on mercury have been replaced by those made of a magnesium alloy. Protection against active radar interference has also been improved. The versions P-15M1 and P-15M2 of the M version are known, in the M1 version the furnace heating was replaced by a heating and ventilation system, with the P-15M2 the separately erected mast for the antenna system was introduced.
P-15N
The P-15N version was tested in 1962 and then introduced. The directional diagram of the antenna has been changed and the system for selecting moving targets has been fundamentally revised. A P-15N was tested in 1963 with a parametric amplifier in the receiving section, which increased the sensitivity by 14% due to the fact that the inherent noise was lower by a factor of 2 to 2.5. However, the low reliability, but in particular the sensitivity to temperature fluctuations, made it necessary to redesign the receiver.
P-15MN
The experiences of the Vietnam and the Six Day War required an improvement in tactical and technical properties. With the anti-radar missile AGM-45 Shrike , introduced in 1963, radar stations on the battlefield were exposed to greater danger. At the same time, the rapidly evolving options for actively jamming radar devices increasingly restricted their possible uses. With the P-15MN version, which was tested in 1970 and then introduced , the interference protection, in particular the protection against the anti-radar missiles available at the time, was improved again, as was the identification device. For this version, different constructive solutions for the system for the selection of moving targets (SBZ) (MTI Moving Target Indication ) were tested.
commitment
Operational principles
The radio measuring station served for the reconnaissance and target assignment of low-flying air targets. Therefore it was primarily used in the command batteries of the anti-aircraft missile systems of the land forces and the air forces / air defense. The P-15 was also used for reconnaissance and control of the air space in the radio technical troops of the land, air and naval forces.
Basically, it was assumed in the Soviet Union that different radar stations would be used together, since a system that meets all the requirements for range, accuracy, resolution, interference immunity and tactical mobility could not be implemented for physical reasons. The use of radar devices that work in different frequency ranges also increased the interference immunity, since a simultaneous disturbance of all frequency bands used by the opponent is unlikely. Due to the different propagation and reflection behavior of electromagnetic waves of different wavelengths, both a large reconnaissance range and a large altitude range, but also sufficient accuracy and the reconnaissance of air targets with stealth properties, could be made possible in the overall system. Last but not least, the spread over the site increased the survivability of the entire system when using anti-radar missiles. The P-15 , like all radar stations developed in the Soviet Union at that time, was therefore a radar device optimized for special requirements that was always used in conjunction with other radar stations and guidance systems. However, this concept requires a large number of different radar systems and thus a high level of effort in the development, procurement and operation of these systems and ultimately led to a high demand for qualified personnel.
Until the beginning of the 1970s, it was used in the anti-aircraft missile regiments of the land forces, which were equipped with the 2K11 Krug and 2K12 Kub anti-aircraft missile systems. The task was the reconnaissance of the airspace, the identification of the air targets to be combated as well as the determination of the target data and their transmission to the anti-aircraft missile systems. The P-15 had already been used in a similar role in the command batteries of the heavy anti-aircraft regiments equipped with the KS-19 flak. In the Air Defense Forces, the P-15 was used with this task in the anti- aircraft missile units equipped with the S-125 Neva system.
In armed forces based on the model of the Soviet Army, the P-15 was also used in the command batteries of the chiefs of the air defense of the armored and motorized rifle divisions and in the radio reconnaissance companies of the land and air forces. Together with other radar stations, it was used to clarify and display the air situation picture, as a rule, target data were not processed and determined here.
States of operations
The P-15 was introduced in the Soviet Army in 1955, but was replaced there from 1974 by the successor P-19 . The system has been exported to numerous countries and is still in use there. In general, robustness, availability and high immunity to interference as well as easy repair are highlighted as the advantages of the system. However, 60 years after the development, the tactical-technical data, especially the interference protection, no longer meet today's requirements.
Use in the NVA
The NVA used the P-15 from the beginning of the 1960s. The system was used both by the air defense of the land forces of the NVA and by the radio technical troops of the LSK / LV .
In the air force / air defense, the P-15 was used in the heavy flak regiments (FR-14, -15 and -16) equipped with the KS-19 . There it was released again in 1961 when these regiments were restructured into anti-aircraft missile regiments. In these regiments equipped with the S-75 Volkhov , it was replaced by the P-12 .
The anti- aircraft missile brigades of the Air Force / Air Defense, equipped with the S-125 Neva anti- aircraft missile system, deployed a P-15 together with a P-12 per brigade as a reconnaissance and target assignment station. Here the P-15 was basically used with the additional mast.
The units of the radio technical troops of the air forces / air defense deployed over the entire area of the former GDR were part of the air defense system on duty and enabled almost complete control and reconnaissance of the airspace. The P-15 was used here both with and without an additional mast. Individual radio technical companies (FuTK) of the NVA use the P-15 in connection with a PRW to lower the radio measuring field lower limit on known and measured radio technical posts (FuTP). (see also radio technical troops )
The air defense of the land forces initially also deployed the P-15 in the two heavy flak regiments of military districts III and V. Used for reconnaissance and target assignment, it was also replaced here by the P-12 from 1962 . The station was introduced into the anti-aircraft regiments of the motorized rifle and tank divisions from 1960. There it replaced the PRW-10 . At first there was a P-15 in the command battery of the regiment, from 1965 the equipment of the command battery was supplemented by a second P-15 . Even when these troops were restructured into anti-aircraft departments from 1961 and later, from 1976, into anti-aircraft missile regiments equipped with 2K12 Kub , the P-15 remained in existence. It was not until 1980 that the P-19 replaced it in this role. The stations that became free were assigned to the anti-aircraft regiments of the mobilization divisions.
As early as 1965, the command batteries of the chiefs of the air defense of the motorized rifle and tank divisions received the P-15 . There were two stations per battery, but in the command batteries of the chiefs of the air defense of the mobilization divisions there was usually only one P-15 .
Another user in the land forces were the radio technology companies of the military districts (FuTK-3 and -5). These companies were built up from 1961. Equipped with radio measuring stations for air surveillance, they replaced the system of air surveillance posts. Initially, these companies each had a P-10 (see radio technical troops ) and a P-15 . From 1965 the equipment was supplemented by the altitude finder PRW-10 (see radio technical troops), which made it possible to determine the altitude of the air targets and thus improved the quality of the aerial situation image.
The NVA carried the versions P-15S ( 1RL13S ), P-15M ( 1RL13M ), P-15MN ( 1RL13MN ), P-15M1 ( 1RL13M1 ) and P-15M2 ( 1RL13M2 ). Other names are only internal language / spelling use of the individual branches of service.
The conversion to the Parol secondary radar device ( 1L23-9 ) was planned from 1989/90, but was no longer implemented due to the changed political situation. The components of the new IFF system that had already been introduced were returned to the Soviet Union in 1990 as so-called sensitive technology in accordance with the two-plus-four treaty .
The existing P-15s were not taken over by the German Armed Forces , but scrapped or given to museums.
Tactical-technical data
| Technical data П-15 Тропа panoramic station 15 Flat Face |
|
|---|---|
| Frequency range | approx. 830 MHz |
| Pulse repetition time | 3-4 ms |
| Pulse repetition frequency | 500-680 Hz |
| Transmission time (PW) | 2.2 µs |
| Reception time | |
| Dead time | |
| Pulse power | 270 kW |
| Average performance | approx. 400 W |
| displayed distance | |
| Distance resolution | 300 m |
| Opening angle | 4 ° |
| Hit count | > 15 |
| Antenna round trip time | 10 s |
Individual evidence
- ↑ a b c d e f g h i РЛС П-15 "ТРОПА" (Russian)
- ↑ a b c Missile and Weapons Technical Service in Kdo.MB III, technical catalog, panoramic station 15 (Russian)
- ↑ a b c d e f g h i j k l m n Reconnaissance station P-15 (P-15)
- ↑ a b Missile and Weapons Service in Kdo.MB III, technology catalog, automated fire control complex 9S44 (Russian)
- ↑ a b Fire control complex K1 (KBU / KPZ)
- ↑ a b c d e f g h takt.-techn. Information on the FuMS P-15
- ↑ Missile and Weapons Technical Service in Kdo. MB III, technical catalog, heating and ventilation system OW-65, OW-95, 015, 030
- ↑ Missile and Weapons Technical Service in Kdo. MB III, technical catalog, electrical unit AB-8
