  We present a generative probabilistic model for a tidal stream and
demonstrate how this model is used to constrain the Galactic potential. The
model takes advantage of the simple structure of a stream in angle and
frequency space for the correct potential. We investigate how the method
performs on full 6D mock stream data, and mock data with outliers included. As
currently formulated the technique is computationally costly when applied to
data with large observational errors, but we describe several modifications
that promise to make the technique computationally tractable.
