Central Redundant Array Megatile

The Central Redundant Array Mega-tile (CRAM) is designed to:

  1. Improve the characterisation of the MWA Phase II hexagon tile beam patterns, and
  2. Improve foreground characterisation and excision for Epoch of Reionisation (EoR) science at Curtin University.

CRAM is used to form redundant baselines with the hexagon tiles. By using the coherent information obtained by simultaneous, co-redundant hexagon-CRAM tiles, foreground contamination from the field edge can be coherently removed, improving the relative EoR-signal-to-foreground-signal ratio.

The tile consists of an array of 8 × 8 dipole antennas and sits at the centre of the south compact hexagon. A zenith-pointing two-stage beamformer is used to sum the signals collected by the CRAM antennas and transmit the summed signals to the correlator via optical fibre links.

Lead investigators of this project are A/Prof. Cathryn Trott, A/Prof. Randall Wayth, Gurashish Singh Bhatia, David Kenney, David Emrich, Jonathon Tickner (Curtin University, Australia), and Dr Sascha Schediwy (UWA, Australia).