This volume brings together state-of-the-art views on ultraviolet radiation, its modelling, and effects from an interdisciplinary panel of international experts. The growing field of research is presented in a sequence from the arrival of UV light at the top of the atmosphere through its transfer to various biological receptors. Modelling and current issues on UV radiative transfer in clear and turbid environments are discussed. Further, measurements and calibration methods are reviewed and, for the first time, established calibration protocols are presented in a coherent way.