Study of Redshifted HI from the Epoch of Reionization with Drift scan
  The detection of the Epoch of Reionization (EoR) in the redshifted 21-cm line
is a challenging task. Here we formulate the detection of the EoR signal using
the drift scan strategy. This method potentially has better instrumental
stability as compared to the case where a single patch of sky is tracked. We
demonstrate that the correlation time between measured visibilities could
extend up to 1-2 hr for an interferometer array such as the Murchison Widefield
Array (MWA), which has a wide primary beam. We estimate the EoR power based on
cross-correlation of visibilities across time and show that the drift scan
strategy is capable of the detection of the EoR signal with comparable/better
signal-to-noise as compared to the tracking case. We also estimate the
visibility correlation for a set of bright point sources and argue that the
statistical inhomogeneity of bright point sources might allow their separation
from the EoR signal.
