  We have simulated the evolution of tidal debris in the Galactic halo in order
to guide our ongoing survey to determine the fraction of halo mass accreted via
satellite infall. Contrary to naive expectations that the satellite debris will
produce a single narrow velocity peak on a smooth distribution, there are many
different signatures of substructure, including multiple peaks and broad but
asymmetrical velocity distributions. Observations of the simulations show that
there is a high probability of detecting the presence of tidal debris with a
pencil beam survey of 100 square degrees. In the limiting case of a single 10^7
Msun satellite contributing 1% of the luminous halo mass the detection
probability is a few percent using just the velocities of 100 halo stars in a
single 1 square degree field. The detection probabilities scale with the
accreted fraction of the halo and the number of fields surveyed. There is also
surprisingly little dependence of the detection probabilities on the time since
the satellite became tidally disrupted, or on the initial orbit of the
satellite, except for the time spent in the survey volume.
