A new narrow beam Doppler radar at 3 MHz for studies of the high-latitude middle atmosphere Original Research Article

A Doppler radar at 3.17 MHz has been installed at Saura close to the Andøya Rocket Range as part of the ALOMAR observatory at Andenes, Norway in summer 2002 to improve the ground based capabilities for measurements of small scale features and turbulence in the mesosphere. The main feature of the new Saura MF radar is the transmitting/receiving antenna which is arranged as a Mills Cross of 29 crossed half-wave dipoles with a minimum beam width of about 7°. Each dipole is fed by its own transceiver, and the individual phase control of the 58 transceiver modules on transmission and reception provides high flexibility in beam forming and pointing as well as transmission switching between ordinary and extraordinary mode circular polarisation. In addition, beams with different widths at the same pointing angle can be formed. For multiple receiver applications (spaced antenna wind measurements, all-sky meteor detections) four independent receiving channels are available. The observation capabilities of the radar are demonstrated by wind measurements using various techniques, turbulent kinetic energy dissipation rates from spectral width measurements, electron density estimates using differential absorption and phase measurements, and meteor observations. The results are discussed in relation with simultaneous observations from co-located MF/HF/VHF radars.