With the right placement of a source in a suitable velocity model it should be possible to model head waves
using a wave equation propagator - for instance, the telescope equation. In fact, examples in this paper do
show such a refraction arrival. Another way to model refractions is the method given in the paper "Upward
Continuing Head Waves" included in this volume. The idea is to create a moving point source along the
velocity interface that simulates the head wave propagating in the faster velocity medium. This way, the
strength of the refraction arrival can be tuned relative to the strength of the reflection arrival.
STANFORD