  We present the calculation of coherent radio pulses emitted by extensive air
showers induced by ultra-high energy cosmic rays accounting for reflection on
the Earth's surface. Results have been obtained with a simulation program that
calculates the contributions from shower particles after reflection at a
surface plane. The properties of the radiation are discussed in detail
emphasizing the effects of reflection. The shape of the frequency spectrum is
shown to be closely related to the angle of the observer with respect to shower
axis, becoming hardest in the Cherenkov direction. The intensity of the flux at
a fixed observation angle is shown to scale with the square of the primary
particle energy to very good accuracy indicating the coherent aspect of the
emission. The simulation methods of this paper provide the foundations for
energy reconstruction of experiments looking at the Earth from balloons and
satellites. They can also be used in dedicated studies of existing and future
experimental proposals.
