Progress in the Simulation and Modelling of Coherent Radio Pulses from Ultra High-Energy Cosmic Particles

In the last decade, many experiments have been planned, designed or constructed to detect Ultra High Energy showers produced by cosmic rays or neutrinos using the radio technique. This technique consists in detecting short radio pulses emitted by the showers. When the detected wavelengths are longer than typical shower length scales, the pulses are coherent. Radio emission can be simulated by adding up the contributions of all the particle showers in a coherent way. The first program to use this approach was based on an algorithm developed more than thirty years ago and referred to as “ZHS”. Since then, much progress has been obtained using the ZHS algorithm with different simulation programs to investigate pulses from showers in dense homogeneous media and the atmosphere, applying it to different experimental initiatives, and developing extensions to address different emission mechanisms or special circumstances. We here review this work, primarily led by the authors in collaboration with other scientists, illustrating the connections between different articles, and giving a pedagogical approach to most of the work.