  Askaryan Radio Array (ARA), a large-scale radio Cherenkov observatory which
scientists propose to develop in Antarctica, aims at discovering the origin and
evolution of the cosmic accelerators that produce the highest energy cosmic
rays by means of observing the ultra high energy (UHE) cosmogenic neutrinos. To
optimize ARA's angular resolution of the incoming UHE neutrinos, which is
essential for pointing pack to its source, the relation between the
reconstruction capabilities of ARA and its design is studied. It is found that
with the noise effect taken into account, in order to make this neutrino
angular resolution as good as possible and detection efficiency as high as
possible, the optimal choice for ARA geometry would be the station spacing of
1.6 km and the antenna spacing of 40 m.
