Transition radiation has been proposed as a possible explanation of the anomalous events detected by the ANITA experiment. These pulses come from the ice surface and do not display the characteristic polarity inversion that the pulses produced by regular cosmic ray showers acquire as they are reflected on the ice surface. A new version of the ZHS Monte Carlo program has been developed to treat coherent transition radiation of showers that go through an interface between air and ice. This program simulates electromagnetic showers that develop through air of constant density and hit an ice surface such as the Antarctic ice sheet, taking into account the magnetic effect of the Earth as included in a recent upgrade of the ZHS code. It can also calculate the induced radio emission at any point in the atmosphere. Simulations of radio pulses with this program are used to address whether the radio pulses produced by showers intercepting the ice surface, including transition radiation, can be observed at the ANITA detector without the characteristic polarity inversion.