EISCAT

From Wikipedia, the free encyclopedia
  (Redirected from Eiscat)
Jump to: navigation, search
The two antennas of the EISCAT Svalbard Radar
EISCAT Kiruna Radar (diameter 32m)

EISCAT (European Incoherent Scatter Scientific Association) operates three incoherent scatter radar systems, at 224 MHz, 931 MHz in Northern Scandinavia and one at 500 MHz on Svalbard, used to study the interaction between the Sun and the Earth as revealed by disturbances in the ionosphere and magnetosphere. At the Ramfjordmoen facility (near Tromsø, Norway), it also operates an ionospheric heater facility, similar to HAARP. Additional receiver stations are located in Sodankylä, Finland, and Kiruna, Sweden. The EISCAT Svalbard radar (ESR) is located in Longyearbyen, Norway. The EISCAT Headquarters are also located in Kiruna.

EISCAT is funded and operated by research institutes and research councils of Norway, Sweden, Finland, Japan, China and the United Kingdom (the EISCAT Associates). Institutes in other countries also contribute to operations, including Russia, Ukraine, Germany and South Korea.

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]

History[edit]

In 1973, the EISCAT proposal — which was originally planned for France, Germany and the three Nordic countries — seemed moribund. Then, Welsh physicist Granville Beynon became involved and by 1975, the agreement was signed, with the UK as a member. The proposal for UK membership had originally been turned down by the appropriate SRC committee. Beynon, however, persuaded the Board to reverse the decision of the committee and as a result of his efforts, hundreds of European scientists have had the opportunity to use the world's most advanced ionospheric radar.[3]

In 2008, Doritos embarked upon an "out-of-this-world" advertising campaign, literally beaming a 30-second advertisement for Doritos brand tortilla chips into a solar system 42 light years away. This project is in collaboration with EISCAT Space Centre in Svalbard. The "You Make It, We'll Play It" contest chose the winning advertisement that was transmitted on June 12, 2008. The ad was beamed towards a distant star, within the Ursa Major constellation which is orbited by planets which may harbor life.[4]

EISCAT facilities[edit]

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 also operates a 32 m VHF-band parabolic dish antenna receiver working at 224 MHz.[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 3D[edit]

EISCAT is planning on building a next generation radar capable of providing 3D monitoring 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 singe 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_3D[edit]

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]

References[edit]

  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. ^ Williams, Phil (April 1996). "Sir Granville Beynon". Retrieved 28 January 2011. 
  4. ^ Highfield, Roger (7 March 2008). "UK astronomers to broadcast adverts to aliens". The Daily Telegraph. Retrieved 28 January 2011. 
  5. ^ a b "What is EISCAT". EISCAT. 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?"
  9. ^ "EISCAT_3D System configuration". Retrieved 2015-05-27. 

External links[edit]

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