  We construct models describing the velocity field in the infall regions of
clusters. The velocity field is the superposition of a systematic component and
a "noise" component accounting for the effects of small scale substructure and
observational errors. This procedure results in models which resemble the
observations (redshifts and angular separations of galaxies surrounding
clusters) quite well. We demonstrate, on simulated data, that it is possible to
estimate correctly the parameters of the systematic velocity component,
knowledge of which allows determination of the mass profile of a cluster. To
avoid systematic effects when analyzing real data, observations from a number
of clusters should be combined. In the absence of sufficient data on other
clusters we illustrate the method by applying it only to the Coma cluster. This
results in mass estimates near the virial radius as well as at the turn around
radius.
