How does it work?

SuperDARN UK will comprise 5 high-frequency coherent-scatter radars at Goose Green in the Falkland Islands, Halley in Antarctica, Hankasalmi in Finland, and Þykkvibær and Stokkseyri in Iceland [view map]. Each radar comprises a main array of 16 log-periodic antennae which transmit and receive radio signals in the HF frequency range from 8 MHz to 20 MHz. The standard 16-beam scan employed by the radar creates a field of view that extends ~52° in azimuth, and from ~200 km to more than 3,000 km in range. The range resolution of the measurements is determined by the transmitted pulse length, which is 300 ms (equivalent to 45 km range) in the common modes of operation. The temporal resolution of complete scans of the field of view is either 1 or 2 min in these common modes.

[Example fan plot with coastline background, lat and long contours, and some los velocity data.]

From the received radio signals of a single radar may be derived various measurements:

  • line-of-sight neutral wind speeds in the mesosphere (~94 km)
  • line-of-sight plasma drift speeds in the ionosphere (~100 km and 400 km altitude)
  • speed, direction and wavelength of gravity waves in the ionosphere
    (aka travelling ionospheric disturbances)
  • polar mesosphere summer echo occurrence (related to polar mesosphere/noctilucent clouds)
  • meteor occurrence and altitude
  • speed, direction and wavelength of ultra-low frequency magnetohydrodynamic waves
  • space weather diagnostics (magnetic reconnection rate, magnetic field-aligned current)
  • sea state

By combining such measurements from more than one radar, these phenomena may be measured across a wider range of scales, allowing estimation of:

  • complete global convection in the ionosphere
  • atmospheric tides and planetary waves

A routine estimate of the ionospheric convection pattern for the period 21:00-21:02 UT on 7 October 2005, derived from northern hemisphere SuperDARN measurements. Radar measurements are indicated by coloured vectors.