The EISCAT Radars

UHF System

EISCAT’s UHF radar is a tristatic system, which currently has a central frequency of 929.5 MHz. It comprises a transmitter at Tromso in Norway and additional passive receivers at Kiruna in Sweden and Sodankyla in Finland. The antennas and receiver hardware at all three sites are basically identical, although of course the transmitter is unique to Tromso. The receivers are also essentially the same as those used for the VHF radar. The UHF system has been operating since 1981, although in that time it has undergone major upgrades of the transmitter and receiver hardware, as well as extensive development of its experimental capabilities.

VHF System

EISCAT’s VHF radar is a monostatic system at Tromso in Norway, which has a central frequency of 224 MHz. The VHF transmitter is housed in the same building as the UHF transmitter and the two transmitters share the same capacitor bank. The VHF antenna is a cylindrical paraboloid of dimension 40 x 120 metres, in four sections. It is steerable only in elevation, though a certain amount of azimuthal coverage is possible using phasing cables. The antenna can be configured in two ways. In one mode the total collecting area of the dish can be used as a single receiver. In the other mode, the dish can be split into two halves to allow transmission and reception of two independent beams. The receivers are essentially the same as those used for the UHF radar. The VHF system has been operating since 1985. In 2001, it underwent a major upgrade of the receiver hardware. There has also been a continuous improvement and development of its experimental capabilities.

ESR System

The EISCAT Svalbard Radar (ESR) is a monostatic radar system located close to Longyearbyen on the island of Spitsbergen. It comprises two dishes, the fully steerable 32m dish, similar in design to those of the mainland UHF system, and a fixed 42m dish, which can operate only in the field-aligned direction. The ESR transmitter is modular in design, using 16 small klystrons based on TV transmitter technology. The transmitter has a central operating frequency of 500 MHz. First operations on the 32m dish occurred in 1996, and the second dish was inaugurated in 2000. Currently (January 2004) the two dishes cannot be used exactly simultaneously. However it is possible to alternate data dumps between the dishes on a timescale of approximately 5 seconds. Two receiver chains are available which (for instance) allow ion line and plasma line data to be recorded simultaneously. The operating system is essentially identical to the EROS4 operating system used on the mainland radars.

The EROS Operating System

The EROS operating system is used to control in real-time the operation of the EISCAT radars.

Other EISCAT Facilities

The EISCAT Scientific Association operates a number of other instruments to enhance and compliment results from the incoherent scatter radars.

IS Radar Factsheet

This useful factsheet, describing the properties of the World's various incoherent scatter radars, was produced for the EISCAT International Workshop at Menlo Park, California, in 2003.

Other Incoherent Scatter Radars

There are a number of other incoherent scatter radars around the world.

Co-ordinates of ground-based facilities

A link to the CEDAR list of ground-based facilities, including the co-ordinates of the various radar sites.