A US military artist's concept of a Dnestr-M/Dnepr.
|Country of origin||Soviet Union, Russia|
|Type||space surveillance (Dnestr)
Early warning radar (Dnestr-M, Dnepr, Dnepr-M)
|Frequency||154–162 MHz (VHF)|
|Pulsewidth||0.8 ms long |
|Range||3,000 kilometres (1,864 mi) 1,900 kilometres (1,181 mi) for targets with an area of 1 m2:75|
|Diameter||Each array is 244 metres (801 ft) long, 20 metres (66 ft) high and 12 metres (39 ft) wide|
|Azimuth||30°, 30 per transmitter giving 120 in total :75|
|Elevation||5° to 35°:75|
|Precision||± 1 km range, 10 min azimuth, 50 min elevation, 5 m/s range rate :75|
|Power||peak power of 1.25 MW per transmitter :75
Radiating power 200 kW :75
Consumed power 2100 kW:75
|Other Names||NATO: Hen House 
GRAU: 5N15 (Dnestr), 5N15M (Dnestr-M), 5N86 (Dnepr)
Dnestr radar (Russian: Днестр) and Dnepr radar (Russian: Днепр), both known by the NATO reporting name Hen House[note 1] are the first generation of Soviet space surveillance and early warning radars. Six radars of this type were built around the periphery of the Soviet Union starting in the 1960s to provide ballistic missile warnings for attacks from different directions. They were the primary Soviet early warning radars for much of the later Cold War. In common with other Soviet and Russian early warning radars they are named after rivers, the Dnestr and the Dnepr.[note 2]
The Dnestr/Dnepr radars were intended to be replaced by the newer Daryal radars starting in the 1990s. Only two of the planned Daryal radars became operational, due to issues such as the dissolution of the Soviet Union. As of 2012, the Russian early warning network still consists of some radars of this vintage. It is likely that all the existing radars will be replaced by the third generation Voronezh radars by 2020.
The Dnestr radar came from work on ballistic missile defence undertaken in the late 1950s and early 1960s. System A, the prototype for the A-35 anti-ballistic missile system, was set up in the Sary Shagan testing grounds, in the Kazakh SSR.:123 Work on the system was led by design bureau KB-1 which proposed using VHF radar RTN (Russian: РТН) and the Dunay-2 UHF radar. Other alternatives were sought from Soviet industry and RTI[disambiguation needed] proposed using VHF radar TsSO-P (Russian: ЦСО-П) and UHF radar TsSS-30 (Russian: ЦСС-30).
TsSO-P (standing for Russian: центральная станция обнаружения – полигонная meaning central detection station – test site) was selected for further development, together with the Dunay-2. TsSO-P had a long horn antenna 250 metres (820 ft) long and 15 metres (49 ft) high. It had an array with an open ribbed structure and used 200 microseconds pulses. Hardware methods were designed for signal processing as the intended M-4 computer could not run. It was built at area 8 in Sary Shagan and was located at . It first detected an object on 17 September 1961.
TsSO-P was effective at satellite tracking and was chosen as the radar of the Istrebitel Sputnik (IS) anti-satellite programme. This programme involved the construction of two sites separated in latitude to form a radar field 5,000 kilometres (3,100 mi) long and 3,000 kilometres (1,900 mi) high. The two sites chosen were at the village of Mishelevka near Irkutsk in Siberia, which was called OS-1, and at Cape Gulshad on Lake Balkhash near Sary Shagan, which was called OS-2. Each site received four Dnestr radar systems in a fan arrangement.:421:433
A Dnestr radar was composed of two TsSO-P radar wings joined together by a two story building containing a joint computer system and command post. Each radar wing covered a 30 degree sector with a 0.5 degree scanning beam. The elevation scanning pattern was a 'spade' with a width of 20 degrees. The radar systems were arranged to create a fan shaped barrier. Of the four radars, called cells (Russian: РЛЯ, tr. RLYa roughly radio location cell), two faced to the west and two faced to the east. All scanned between +10 degrees and +90 degrees in elevation.
Construction at the two sites started between 1962 and 1963 with improvements in the TsSO-P test model being fed back into the deployed units. They gained an M-4 2-M computer with semiconductors, although the rest of the radar used Vacuum tubes. The radar systems were completed in late 1966 with the fourth Dnestr at Balkhash being used for testing. In 1968 the Dnepropetrovsk Sputnik target satellite, DS-P1-Yu, was used to test the ability of the system.
Parallel with the implementation of the Dnestr space surveillance units, a modified version of the original Dnestr units, Dnestr-M radar, was being developed to act as an early warning radar to identify attacks by ballistic missiles. The first two were built at Murmansk in northern Russia (Olenegorsk – RO-1) and near Riga in the then Latvian SSR (Skrunda – RO-2). They constituted the beginning of the Soviet SPRN network, the equivalent of the NATO BMEWS.:421
The first Dnestr-M at Olenegorsk was completed by 1968. In 1970, the radars at Olenegorsk and Skrunda, and an associated command centre at Solnechnogorsk, were accepted for service. According to Podvig (2002), it seems they were positioned to identify missile launches from NATO submarines in the Norwegian and North Seas.
The Dnestr-M included many improvements over the previous versions such as an increase in the pulse length from 200μs to 800μs which increased the range of objects identified, more semiconductors, and many other scanning and processing changes.
A version of this radar was built at the Sary Shagan test site and was called TsSO-PM (Russian: ЦСО-ПМ). After this had completed tests in 1965 it was decided to upgrade nodes 1 and 2 of the two OS sites to Dnestr-M, keeping nodes 3 and 4 as Dnestr. These radars remained as space surveillance radars which scanned between +10 and +90 degrees, comparative to scanning between +10 and +30 degrees for the missile warning radars. A space surveillance network of four Dnestrs and four Dnestr-Ms, and two command posts was formally commissioned in 1971.
Work to improve the radar continued. An improved array was designed which covered 60 degrees rather than 30. The first Dnepr radar was built at Balkhash as a new radar, cell 5. It entered service on 12 May 1974. The second was a new early warning station at Sevastopol. New Dneprs were also built at Mishelevka and another at Skrunda, and then one at Mukachevo. The remaining radars were all converted to Dnepr with the exception of cells 3 and 4 at Balkhash and Mishelevka which remained space surveillance radars.:422
Each Dnepr array is a double sectoral horn antenna 250m long by 12 m wide. It has two rows of slot radiators within two waveguides. At each end of the two arrays, there is a set of transmitting and receiving equipment. It emits a signal covering a sector 30 degrees in azimuth and 30 degrees in elevation, with the scanning controlled by frequency. Four sets mean the radar covers 120 degrees in azimuth and 30 degrees in elevation (5 to 35 degrees).
These radars have been installed at six different radar stations and as of 2012 are operational at three – Balkhash, Mishelevka and Olenegorsk. The 1972 Anti-Ballistic Missile Treaty required that early warning radars were located on the periphery of national territory and faced outwards. This caused problems when the Soviet Union collapsed in 1991 as many of the radar stations were now in newly independent states. The first station to close was Skrunda, in newly independent Latvia. A 1994 agreement between Russia and Latvia agreed that the two Dnepr radars there would stop working in 1998, and would be fully demolished by 2000.:129:65:426
Russia signed an agreement with Ukraine in 1992 allowing it to continue using the Dnepr radars at Sevastopol and Mukachevo. The stations were run by Ukrainian personnel and data was sent to the headquarters of the Russian early warning system in Solnechnogorsk. In 2008 Russia announced that it was pulling out of the agreement with Ukraine and that the last data given to Russia from the stations would be in 2009.:76 The Ukrainian government announced that the stations were to be used part-time for space surveillance.
The remaining stations in Russia are due to be replaced by the Voronezh radar. The Dneprs in Mishelevka, Irkutsk will close once the second array of the new Voronezh radar is operational. The Dnepr at Olenegorsk, Murmansk will be replaced by a Voronezh as well. It is planned to start construction there in 2017.
|OS-1||Mishelevka Radar Station, Irkutsk, Siberia||70, 200||Dnepr||1972–1976||Operational.|
|135||Dnestr-M||1964–1970||Dismantled 1970s. Replaced by Dnepr radar at the new position.|
|265||Dnestr||1964–1968||Modernised to an incoherent scatter radar. Used for research since 1993.|
|265||Dnestr||1964–1968||Decommissioned 1990s. Dismantled.|
|135||Dnestr-M||1967–1972||Modernised to Dnepr 1976. Operational.|
|OS-2||Balkhash Radar Station, Sary Shagan||270||Dnestr||1964–1967||Decommissioned September 1995. Dismantled.|
|270||Dnestr||1964–1967||Decommissioned January 1984. Dismantled.|
|60||Dnestr-M||1964–1971||Modernised to Dnepr 1974. Decommissioned January 1984. Dismantled.|
|60||Dnestr-M||1964–1971||Modernised to Dnepr 1974. Decommissioned September 1988. Dismantled.|
|180, 124||Dnepr||1968–1972||Operational from 1974.|
|RO-1||Olenegorsk-1, Kola Peninsula||323, 293||Dnestr-M||1965–1968||Modernised to Dnepr 1978, works with the Daugava radar. Operational.|
|RO-2||Skrunda-1, Baltics||323, 293||Dnestr-M||1965–1969||Modernised to Dnepr 1979. Demolished 1999.|
|8, 248||Dnepr||1968–1976||Demolished 1999.|
|RO-4||Sevastopol Radar Station, Crimea||172, 230||Dnepr||1968–1979||Closed 2009. Planned to be modernised 2016.|
|RO-5||Mukachevo Radar Station, Transcarpathia||196, 260||Dnepr||1968–1979||Closed 2009. Derelict?|
- "Incoherent Scatter Radar". East Siberian Center for the Earth's Ionosphere Research. 2002-06-25. Archived from the original on 2012-12-02. Retrieved 2012-02-02.
- "Днепр" на Балхаше ["Dnepr" in Balkhash] (in Russian). Novosti Kosmonavtiki. July 2009. Archived from the original on 2010-11-09. Retrieved 2012-01-27.
- Мощные РЛС дальнего обнаружения РЛС СПРН и СККП [Powerful radar early warning radar early warning system and space surveillance] (in Russian). RTI Mints. Archived from the original on 2012-12-02. Retrieved 2012-01-30.
- Nikolai Spassky, ed. (2002). Encyclopedia "Russia’s Arms and Technologies. The XXI Century Encyclopedia": Volume 5 — "Space weapons" (in English and Russian). Moscow: Publishing House "Arms and Technologies". ISBN 5-93799-010-2.
- Podvig, Pavel (2002). "History and the Current Status of the Russian Early-Warning System" (PDF). Science and Global Security 10: 21–60. doi:10.1080/08929880212328. ISSN 0892-9882.
- Forden, Geoffrey (May 3, 2001). "Reducing a Common Danger: Improving Russia's Early-Warning System" (PDF). Cato Policy Analysis No. 399 (Cato Institute).
- Zaloga, Steven (2002). The Kremlin's Nuclear Sword: The Rise and Fall of Russia's Strategic Nuclear Forces 1945–2000. Washington, DC: Smithsonian Institution Press. ISBN 978-1588340078.
- Ivantsov, Viktor. От "Днестра" до "Днепра" [From Dnestr to Dnepr] (in Russian). VKO. Archived from the original on 2012-12-02. Retrieved 2012-07-22.
- O'Connor, Sean (2009). "Russian/Soviet Anti-Ballistic Missile Systems". Air Power Australia. Archived from the original on 2012-12-02. Retrieved 2012-01-07.
- "Hen House". Federation of American Scientists. Archived from the original on 2012-12-02. Retrieved 2012-01-27.
- Bukharin, Oleg; Kadyshev, Timur; Miasnikov, Eugene; Podvig, Pavel; Sutyagin, Igor; Tarashenko, Maxim; Zhelezov, Boris (2001). Podvig, Pavel, ed. Russian Strategic Nuclear Forces. Cambridge, Massachusetts: MIT Press. ISBN 0-262-16202-4.
- Votintsev, Yu.V. (1993). "Unknown Troops of the Vanished Superpower". VOYENNO-ISTORICHESKIY ZHURNAL 11: 12–27. Archived from the original on 2012-12-02.
- "DS-P1-Yu (11F618)". Gunter's Space Page. 2012-03-31. Archived from the original on 2012-12-02. Retrieved 2012-09-16.
- Votintsev, Yu.V. (1993). "Unknown Troops of the Vanished Superpower". Voyenno-Istoricheskiy Zhurnal 9: 26–38. Archived from the original on 2012-12-02.
- Karpenko, A (1999). "ABM AND SPACE DEFENSE". Nevsky Bastion 4: 2–47. Archived from the original on 2012-12-02.
- Potekhin, Anna (2011-01-16). Зелёных вам фонарей! [Green light for you!] (in Russian). Красная звезда [Krasnaya Zvezda]. Retrieved 2012-04-10.
- Модернизация радаров СПРН в Северо-Западном округе начнется в 2015 году [Upgrading early warning radars in the Northwest District will begin in 2015] (in Russian). Lenta.ru. 2011-12-12. Archived from the original on 2012-12-02. Retrieved 2012-01-09.
- Marinin, I (2011). Отечественной СПРН – 40 лет [Patriotic SPRN – 40 years] (in Russian). Novosti Kosmonavtiki. Retrieved 20 June 2012.[dead link]
- Marinin, I (2011). Отечественной СПРН – 40 лет [Patriotic SPRN – 40 years]. Novosti Kosmonavtiki (in Russian) (Eastview) (339): 44–46. ISSN 1561-1078.(subscription required)
- Chandra, Ramesh (2004). Minority: Social and Political Conflict. Delhi, India: Isha Books. ISBN 978-81-8205-140-9.
- Hadonina, Dzidra (1998). "Environmental Situation and Remediation Plans of Military Sites in Latvia". In Fonnun, F; Paukstys, B; Reimer, K et al. Environmental Contamination and Remediation Practices at Former and Present Military Bases. Springer. pp. 63–69. ISBN 978-0792352471.
- Wilk, Andrzej (2008-01-29). "Russia starts to dismantle the Soviet early warning system". Centre for Eastern Studies. Archived from the original on 2012-12-02. Retrieved 2012-07-09.
- Kramnik, Ilya (2009-02-26). Арифметика СПРН: минус два "Днепра", плюс один "Воронеж" [Early warning arithmetic: minus two Dnepr, plus one Voronezh] (in Russian). RIA Novosti. Archived from the original on 2012-12-02. Retrieved 2012-07-15.
- "Russia to stop using Ukrainian radars". RIA Novosti. 2008-02-04. Archived from the original on 2012-12-02. Retrieved 2012-01-30.
- Baev, Pavel (2010). "Neither Reform nor Modernisation: the Armed Forces Under and After Putin's Command". In Galeotti, Mark. The Politics of Modern Security in Russia. Ashgate. pp. 69–88. ISBN 978-0-7546-7408-5.
- Podvig, Pavel (2009-02-12). "Armavir radar fills the gap". Russian strategic nuclear forces. Archived from the original on 2012-12-02. Retrieved 2012-01-09.
- "Ukrainian radars withdrawn from operation in Russia's interests to undergo technical maintenance". Kyiv Post. 2009-02-26. Archived from the original on 2012-12-02. Retrieved 2012-07-11.
- "Source: Ukraine radar to be used to protect German satellites". Kyiv Post. 2010-02-09. Archived from the original on 2012-12-02. Retrieved 2012-07-11.
- Davletgalieva, Anel; Konovalov, Ivan (2010). "CITIZENS OF KAZAKHSTAN WERE HEAPED UP WITH DEBRIS OF THE USSR". Defence & Security (Eastview) (9).(subscription required)
- "Russia Turns on New Missile Warning Radar". RIA Novosti. 2012-05-23. Archived from the original on 2012-12-02. Retrieved 2012-07-27.
- Podvig, Pavel (2011-06-21). "Daryal-U radar in Mishelevka demolished". Russian strategic nuclear forces. Archived from the original on 2012-12-02. Retrieved 2012-01-30.
- Holm, Michael (2011). "46th independent Radio-Technical Unit". Soviet Armed Forces 1945–1991. Archived from the original on 2012-12-02. Retrieved 2012-01-30.
- Holm, Michael (2011). "49th independent Radio-Technical Unit". Soviet Armed Forces 1945–1991. Archived from the original on 2012-12-02. Retrieved 2012-04-10.
- Вручение знамени 16601 [Presentation of the Flag 16601] (VIDEO) (in Russian). Zvezda News. 2010-12-12. Archived from the original on 2012-12-02. Retrieved 2012-02-01.
- SityShooter (2011). "РЛС "Днестр" – "Днепр-М" (actually is Daugava left)" [Radar Dnestr-Dnepr-M] (PHOTOGRAPH) (in Russian). Archived from the original on 2012-12-02. Retrieved 2012-01-29.
- Всевидящий глаз России [Seeing Eye Russia]. Novosti Kosmonavtiki (in Russian) (Eastview) (5): 52–53. May 2009.(subscription required)
- РЛС "Днепр" в Севастополе заступит на боевое дежурство в 2016 году [The Dnepr radar in Sevastopol brings on combat duty in 2016] (in Russian). RIA Novosti. 2014-10-04.
- "Russia Won't Rent Ukrainian Radar". Kommersant. 2008-01-16. Retrieved 2012-01-30.
- Haiworonski, Oleksa (2010-11-07). ""Dniepr" radiolocation unit at Cape Chersones" (PHOTOGRAPH). Panoramio. Archived from the original on 2012-12-02. Retrieved 2012-01-30.
- Podvig, Pavel (2008-08-25). "Russia pulls out of an early-warning arrangement with Ukraine". Russian strategic nuclear forces. Archived from the original on 2012-12-02. Retrieved 2012-02-01.
- Set of photos from inside the Balkhash Dnepr from Novosti Kosmonavtiki, July 2009
- Set of photos of an Irkutsk Dnepr from Novosti Kosmonavtiki, May 2012
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