Hen House / Dnestr / Dnepr / Daugava

Operational ballistic missile early warning was provided by 11 large HEN HOUSE detection and tracking radars deployed at six locations on the periphery of the USSR. Most of these radars are located outside the territory of Russia. These radars can distinguish the size of an attack, confirm the warning from the satellite and over-the-horizon radar systems, and provide target-tracking data in support of antiballistic missile (ABM) deployments.

There are three variants of the HEN HOUSE radar, each named after a major river of the Soviet Union. The first variant, Dnestr, is named after the Dnestr River [also spelled Dnister and Nistru], rises in the Carpathian Mountains in western Ukraine and flows into the Black Sea some 32 km from Odessa. The second variant, Dnepr, is named after the Dnepr River, which is over 2,200 km long from its source west of Moscow to its swampy, delta mouth at the Black Sea. Its course takes it generally south and west past Smolensk, Kiev, Dnepropetrovsk, and Kherson. The third variant, Daugava, is named after the Zapadnaya Dvina/Daugava river, which flows through Russia, Belarus and Latvia over a length of 1000 km. The river is called the Daugava in Latvia. The capital of Latvia, Riga, lies on the bank of the Daugava River not far from its estuary into the Baltic Sea.

The Dnestr above-the-horizon early warning radars were developed by the Radio-Electronic Research Institute (NIRI) of the Soviet Academy of Sciences under the supervision of A. Mints (Chief Designer Yu. Polyak). The radars are deployed in pairs sharing a common azimuth, and Western assessments appear to count each pair as a single radar, though in fact each such complex consists of a total of four antenna. The maximum detection range of the radars for a target with a range of 1,600 kilometers was 1,440 kilometers, for a missile launched at 3,200 kilometers the detection range was 2,400 kilometers, and for an intercontinental missile [with a range of 8,000 kilometers] the detection range was 3,520 kilometers. In 1967 the first Dnestr specialized radiotechnical station was tested at Lake Balkhash in Kazakhstan just north of Sary Shagan. The first Dnestr-type radars, designed to warn of a missile attack and monitor outer space, were deployed in Kazakhstan and at Angarsk in Siberia in 1967-1968. The Dnestr-type radar deployed in Kazakhstan was the first Soviet radar designed to track satellites. In 1968, a radar complex consisting of eight Dnestr radars designed to monitor outer space was successfully tested, forming a continuous radar barrier covering a sector of over 5,000 km in length and up to 3,000 km in altitude.

In 1960-61, the Mints Radiotechnical Institute (RTI) began designing a fundamentally new radar, the Dnestr-M type, which for the first time used a pulse compression method destined to process the incoming signals emitted by powerful radars. This made it possible to take full advantage of the radar's high accuracy and resolution characteristics. The external configuration of the Dnestr-M was nearly identical to that of the Dnestr, except that the antenna array was Y-shaped, rather than in a straight line. Construction of the upgraded Dnestr-M radar, which was to be stationed in the trans-polar area (RO-1 at Olenegorsk in Murmansk) and Latvia (RO-2 at Skrunda, near Riga), began in 1963-1964. The state tests of the Dnestr-M radar were conducted between 1968 and 1976 in the trans-polar area. Tests of these radars within radiotechnical complexes deployed in the Trans-Polar regions, in Latvia and near Moscow were completed in 1976. The Dnestr-M radar is equipped with transceiving phased array 200 meters long and 20 meters high. The radar is placed on the sloped surface of a building 200 meters long and up to 75 meters high. It can monitor a sector of space in the range of azimuths 220-3,100 km and at a distance up to 5,000 kilometers.

In 1969, in cooperation with the customer and other enterprises of the industry, the Mints Radiotechnical Institute (RTI) developed the Ekvator project, which defined the major principles of the Soviet missile attack warning [MAW] system.

To set an uninterrupted radar field in the western, southwestern, and southern missile danger zones, radar centers were constructed between 1968 to 1972 in Western Ukraine, Crimea, Kazakhstan, Siberia and the Kola Peninsula. The Dnepr radars developed by the Mints Institute, formed the basis for these centers. The Dnepr radar is apparently a further evolution of the Dnestr-M previously deployed at at Olenegorsk and at Skrunda, and some accounts imply that the difference is merely one of nomenclature. Together with the Daryal radars deployed later, these radars formed the basis for the Soviet ground-based MAWS. In early 1970s, building of the new Dnepr radars began near Mukachevo, Sevastopol, Irkutsk, and Lake Balkhash. There is considerable disagreement among sources as to the location of the second Dnepr in Ukraine, with many sources claiming in error that it is located at Nikolayev [Mykolayiv], rather than the actual location at Sevastopol. The main distinguishing features of the Dnepr radar and its modified Dnepr-M version are the improved signal processing methods employed and, particularly, the coherent accumulation of pulse bursts, better control of the radar antenna radiation pattern and enhanced noise immunity.

The Dnepr billboard array is inclined at about 45º from the vertical. It is reported that the performance of the Dnepr is comparable to that of the FPS-50 detection radars originally used in the US Ballistic Missile Early Warning System (BMEWS), which had a detection range of about 6,000 km and a track-while-scan capability. The Dnepr is believed to operate at about 150 MHz with a variety of PRFs from 25 to 100 pps, variable pulsewidths, a complicated beam scan pattern with two beams scanning in azimuth, two scanning in elevation and one scanning in a circular pattern. Peak power is believed to exceed 10 MW.

The radiation control of the antennas was improved, the principle of coherent accumulation of pulses was used, and noise immunity was increased. Sounding signals were emitted in the decimeter range, and the detection range increased to 4,800 km. After passing tests in the Arctic, the radar "Dnepr-M" was put into operation.

The Daugava represents the third variant of the HEN HOUSE, with a pair of antenna deployed in a sharp V-shape, covering a wider angle than the Y-array of the Dnepr. To ensure that the information obtained under heavy noise conditions caused, for example, by the northern lights in the polar ionosphere, is reliable, an additional Daugava receiving station was erected at the northern center. It was equipped with a large-aperture phased array having phase-phase control capability and featured a hybrid super-high frequency microwave technology that was used there for the first time.

On the basis of the Dnepr and Daugava radars, new generation radars of the Daryal series were designed.

In February 2005 Colonel-General Anatoly Toropchin, commander of Ukraine's Air Force, demanded that Moscow pay more for information received by the Russian early-warning network from Dnieper radars in Mukachev and Sevastopol. Kiev was getting $1.2 million for this information each year. General Toropchin believed that this sum total does not cover the Ukrainian Defense Ministry's expenses. First of all, this concerns the spending on personnel that cater to Russian needs. "Russia annually pays $5 million for the Daryal radar in Azerbaijan, bur Ukraine receives only $1.2 million for its two radars," the general complained. Consequently, the presidents and governments of the two countries must rectify the situation.

Moscow and Astana agreed 05 December 2015 the terms of Russia’s use of a Kazakh radio communications center as part of Russia’s ballistic missile early warning system. The head of the Defense Ministry’s international cooperation department, Sergei Koshelev, said the measure would enhance Russia’s defense capability and help build a unified regional air and missile defense system. “It will also give boost to the mutually-beneficial defense cooperation between our two countries,” Koshelev added. The Balkhash radio communications facility is an important element of Russia’s ballistic missile early warning system, which ensures the security of all members of the Collective Security Treaty Organization of Russia, Kazakhstan, Kyrgyzstan, Belarus, Armenia and Tajikistan. The Dnepr long-distance radar, which is part of the Balkhash facility, provides round-the clock observation of outer space and registers ballistic missile launches in the entire southeastern collective security region.

Sources and Methods

• ABM AND SPACE DEFENSE A. Karpenko Nevsky Bastion, No. 4, 1999, pp. 2-47
• 50 YEARS OF THE MINTS RADIOTECHNICAL INSTITUTE Victor Sloka Military Parade July-August 1996