  Distinguishing the signals due to scattering of WIMP dark matter off of
nuclear targets from those due to background noise is a major challenge. The
Earth's motion relative to the galactic halo should produce halo-dependent
seasonal modulation in the event rate, but it also should produce an angular
signal that is both far stronger and less ambiguous. Distinct patterns in the
recoil spectrum can reflect the details of the galactic halo. We derive a new
formalism to calculate angular event rates, and present the predicted angular
signal for a variety of halo models and calculate the number of events needed
to distinguish a dark matter signal from an isotropic background.
