  Atom lasers based on rf-outcoupling can be described by a set of coupled
generalized Gross-Pitaevskii equations (GPE). We compare the theoretical
predictions obtained by numerically integrating the time-dependent GPE of an
effective one-dimensional model with recently measured experimental data for
the F=2 and F=1 states of Rb-87. We conclude that the output of a rf-atom laser
can be well described by this model.
