airisThe Andoya Imaging Riometer for Ionospheric Studies – AIRIS

The AIRIS system has a sophisticated phased array antenna which produces 49 narrow beams, of the order of 12 degrees beam width. The riometer outputs are all sampled once per second.

The AIRIS system is capable of examining ionospheric electron density perturbations in both small time scale (1 second), as well as small spatial scale (approx. 20 km). This enables the structure and dynamics of the energetic particle precipitation over a large field of view to be determined with a spatial resolution, which is not at presently obtainable with any other technique.

Preliminary data from the new Imaging riometer is available on-line at all time.

The research topics employing the AIRIS system include:

  • Ionospheric scintillation and its effect upon satellite communication.
  • Auroral absorption and its effect upon HF wave propagation
  • Dynamics and structure of energetic particle precipitation
  • Artificially induced absorption and scintillation

The AIRIS is a part of the Global Riometer Array (Gloria) which is an international collaborative program for scientific investigation of the role of particle precipitation in the sun-earth connection. In partucular it aims at an improved understanding of the coupling mechanism between the solar wind, magnetsophere and the ionosphere. There are currently over 20 imaging riometer arrays worldwide.

AIRIS Technical data:
– 38.2 MHz, BW: 250 kHz, Sens: 0.05 dB
– 64 (8×8) crossed dipoles, filled array
– 49 narrow beams, 12 degrees BW
– Spatial resolution: 20 km
– Sampling rate: 1 second.
– Digital Rx and beam shaping FPGA
– Fixed circular polarization
– 45 deg. antenna angle to minimize mutual coupling.