An approximate analytical solution for electric surface currents induced on a planar dielectric half-space by a normally incident Gaussian beam is presented. This solution provides a useful tool for testing discretization methods in point matching moment method codes for penetrable rough surface scattering which use a Gaussian beam tapered incident field to avoid edge effects. For one example case illustrated, the surface current solution obtained can be shown to satisfy standard impedance boundary condition integral equations at the beam center to within 0.01% accuracy, and a separation of individual term contributions to the entire integral equation enables a detailed check of moment method discretization procedures to be performed.¿ 1997 American Geophysical Union