We have simulated the evolution of tidal debris in the Galactic halo in ord
er to guide our ongoing survey to determine the fraction of halo mass accre
ted 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 p
eaks and broad but asymmetrical velocity distributions. Observations of the
simulations show that there is a high probability of detecting the presenc
e of tidal debris with a pencil-beam survey of 100 deg(2). In the limiting
case of a single 10(7) M-. satellite contributing 1% of the luminous halo m
ass the detection probability is a few percent using just the velocities of
100 halo stars in a single 1 deg(2) field. The detection probabilities sca
le with the accreted fraction of the halo and the number of fields surveyed
. There is also surprisingly little dependence of the detection probabiliti
es on the time since the satellite became tidally disrupted, or on the init
ial orbit of the satellite, except for the time spent in the survey volume.