  From the perspective of quantum information theory, the effect of Unruh
radiation on a two-level accelerated detector can be modeled as a quantum
channel. In this work, we employ the tools of channel-position finding to
locate Unruh channels. The signal-idler and idler-free protocols are explored
to determine the position of the target Unruh channel within a sequence of
background channels. We derive the fidelity-based bounds for the ultimate error
probability of each strategy and obtain the conditions where the signal-idler
protocol is superior to the protocol involving idler-free states. It is found
that the lower bound of the error probability for the signal-idler scheme
exhibits clear advantages in all cases, while the idler-free scheme can only be
implemented when the temperature of the two channels is very close and the
number of initial states is insufficient. Interestingly, it is shown that the
optimal detection protocol relies on the residual correlations shared between
the emitted probe state and the retained idler modes.
