the science of the earths climate requires reliable global data sets to validate numerical simulation models and to identify regional and global fluctuations and trends. this book presents ways to derive such data from space-borne and ground-based passive and active measurements in the entire electromagnetic spectrum. both descriptions of the basics of such methods and the most recent advancements are included. the book spans the field from clouds and the planetary radiation budget down to surface processes and ocean properties. extensive reference lists enable readers to penetrate deeper into each subject.