  We describe a new method of transient point source localization for
coded-aperture X-ray detectors that we have applied to data from the HETE
Wide-Field X-Ray Monitor (WXM). The method is based upon the calculation of the
likelihood function and its interpretation as a probability density for the
transient source location by an application of Bayes' Theorem. The method gives
a point estimate of the source location by finding the maximum of this
probability density, and credible regions for the source location by choosing
suitable contours of constant probability density. We describe the application
of this method to data from the WXM, and give examples of GRB localizations
which illustrate the results that can be obtained using this method.

Astrophysics