  Interferometric telescopes are instrumental for the imaging of distant
astronomical bodies, but optical loss heavily restricts how far telescopes in
an array can be placed from one another, leading to a bottleneck in the
resolution that can be achieved. An entanglement-assisted approach to this
problem has been proposed by Gottesman, Jennewein, and Croke (GJC12) [Physical
Review Letters, 109(7):070503, July 2011], as a possible solution to the issue
of optical loss if the entangled state can be distributed across long distances
by employing a quantum repeater network. In this paper, we propose an
alternative entanglement-assisted scheme that interferes a two-mode squeezed
vacuum state with the astronomical state and then measures the resulting state
by means of homodyne detection. We use a continuous-variable approach and
compute the Fisher information with respect to the mutual coherence of the
astronomical source. We show that when the Fisher information is observed
cumulatively at the rate at which successful measurements can be performed, our
proposed scheme does not outperforms the traditional direct detection approach
or the entanglement-assisted approach of GJC12.
