Patterns of primary beam non-redundancy in close-packed 21 cm array observations

  title={Patterns of primary beam non-redundancy in close-packed 21 cm array observations},
  author={Samir Choudhuri and Philip Bull and Hugh Garsden},
Radio interferometer arrays such as HERA consist of many close-packed dishes arranged in a regular pattern, giving rise to a large number of ‘redundant’ baselines with the same length and orientation. Since identical baselines should see an identical sky signal, this provides a way of finding a relative gain/bandpass calibration without needing an explicit sky model. In reality, there are many reasons why baselines will not be exactly identical, giving rise to a host of effects that spoil the… 
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