EISCAT (European Incoherent Scatter Scientific Association) operates three incoherent scatter radar systems in Northern Scandinavia and Svalbard. The facilities are used to study the interaction between the Sun and the Earth as revealed by disturbances in the ionosphere and magnetosphere.

The two antennas of the EISCAT Svalbard Radar
EISCAT Kiruna Radar (diameter 32m)

LocationEdit

At the Ramfjordmoen facility, near Tromsø, Norway, EISCAT operates a UHF and a VHF transmitter and receiver. In Tromsø EISCAT also operates a ionospheric heater facility (Heating).

Receiver stations are located in Sodankylä, Finland, and Kiruna, Sweden.

The EISCAT Svalbard radar (ESR) outside Longyearbyen, Norway also operates in the UHF band.

The EISCAT Headquarters is located in Kiruna.

The system was also tested for space debris tracking and the radars were proven to be capable of statistical observations of low-Earth-orbit (LEO) debris (altitudes of 500 to 1500 km) down to 2 cm in size. Since these measurements are insufficient to determine complete orbits, the radar has only limited space surveillance value.[1] Because the space debris tracking change is only a dedicated back-end computer system, the primary EISCAT observations are not compromised. As a result of that, the EISCAT radars allow continuous monitoring of the LEO debris in a beam park mode, functioning as a space surveillance system part of the European Space Agency's Space Situational Awareness Programme (SSA).[2]

HistoryEdit

EISCAT was founded in December 1975, as an association of research councils in six member countries. But the plans to establish a research facility focusing on incoherent scatter technology in the Northern Lights zone, started as early as 1969. Many meetings with interested researchers were held in the early 70s, but it was not until Professor Sir Granville Beynon invited to a meeting in 1973, where a board and a chairman were appointed, as the work really began. In 1974, the Council presented a report on how the organisation, operations and implementation of EISCAT's UHF system could take place, and at the end of 1975 the first six member states agreed to start building EISCAT.

The member countries are now Sweden, Norway, Finland, Japan, China and the United Kingdom. The members have changed somewhat: Germany is no longer a full member, France was a member from the start of the organization in 1975 until 2005, while Japan and China were added later (1996 and 2007 respectively).[3]

EISCAT is governed by The EISCAT Council, which consists of representatives from research institutions in the various member countries. Two committees, the Administrative and Financial Committee (AFC) and the Advisory Scientific Committee (SAC), assist the Council in its work.[4]

EISCAT facilitiesEdit

 
EISCAT Ramfjordmoen facility (near Tromsø) in winter
 
EISCAT Sodankylä receiver antenna (diameter 32m) after conversion to 224 MHz (crossed dipole replaced Cassegrain subreflector at focal point)

EISCAT operates several facilities north of the Scandinavian arctic circle.[5]

  • At Ramfjordmoen, near Tromsø, Norway the EISCAT facility has: a Ionospheric heater with HF radar capabilities; a tristatic VHF radar at 224 MHz with a 4 x 30m-by-40m parabolic cylinder antenna; and a monostatic UHF radar at 931 MHz with a 32 m parabolic dish antenna.[6] From the start in 1981 the UHF radar was a steerable tristatic system, but due to interference from telecommunications in the 930 MHz band, the remote receivers were converted to receive the VHF signal during 2012.
  • At Kiruna, EISCAT operates a 32 m parabolic dish antenna receiver which was originally part of the tristatic UHF system but was converted to receive the VHF frequency (224 MHz) during 2012.[6]
  • At Sodankylä, Finland, EISCAT operates a 32 m parabolic dish antenna receiver which was originally part of the tristatic UHF system but was converted to receive the VHF frequency (224 MHz) during 2012.[6]
  • At Longyearbyen, on the Norwegian Svalbard archipelago, EISCAT operates the EISCAT Svalbard radar (ESR). It consists of a 32 m steerable parabolic dish antenna and a 42 m field aligned antenna, operating at 500 MHz.[5][6]

The Tromsø VHF transmitter, together with the Kiruna and Sodankylä VHF receivers, form a multistatic radar system.

Additionally, the Kilpisjärvi Atmospheric Imaging Receiver Array (KAIRA), near Kilpisjärvi, Finland can also serve as a VHF receiver in conjunction with the Tromsø transmitter.[7]

EISCAT 3DEdit

EISCAT is building a new generation research radar capable of providing better research possibilities of the atmosphere and ionosphere. The new system is called EISCAT_3D.

In 2008, the European Strategy Forum on Research Infrastructures selected EISCAT_3D for its "Roadmap 2008 for Large-Scale European Research Infrastructures for the next 20–30 years."[8]

EISCAT_3D will be a multistatic radar composed of five phased-array antenna fields. each field will have around 10,000 crossed dipole antenna elements. All five sites will act as receivers, with a single core site transmitting at 233 MHz (VHF band). The sites will be spread over Finland, Norway and Sweden. Each site will have a central array, surrounded by a set of smaller arrays, providing a high spatial resolution via aperture synthesis.[9]

Preparations for EISCAT_3DEdit

During the summer of 2017, EISCAT will build a 91-element subarray at the site at Ramfjordmoen for hardware testing purposes and the full system is expected to be operational around 2021. The KAIRA system is also a pathfinder for the development of EISCAT_3D.[7]

ReferencesEdit

  1. ^ "Europe's Eyes on the Skies" (PDF). ESA. Retrieved 2015-05-06.
  2. ^ "ESA - Space Debris - Scanning & observing". ESA. Retrieved 2015-05-06.
  3. ^ "EISCAT Annual Report 1976" (PDF). EISCAT website.
  4. ^ "The EISCAT Council".
  5. ^ a b "What is EISCAT". EISCAT. Archived from the original on 2015-10-04. Retrieved 2015-05-23.
  6. ^ a b c d "The EISCAT facilities". EISCAT. Retrieved 2017-03-09.
  7. ^ a b "SGO: KAIRA". SGO. Retrieved 2015-05-24.
  8. ^ ""What is Eiscat 3D?"". Archived from the original on 2015-05-27. Retrieved 2012-02-14.
  9. ^ "EISCAT_3D System configuration". Retrieved 2015-05-27.

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External linksEdit

Coordinates: 69°35′10.67″N 19°13′28.62″E / 69.5862972°N 19.2246167°E / 69.5862972; 19.2246167