The book describes the steps which lead from the raw signals measured in space to firstly calibrated an comparable long term data sets and in a second step to information for user communities. From the primarily spectral radiances information is inferred which is needed in the context of modeling climate variability such as the variable surface albedo and temperatures, soil moisture, and energy and water vapour fluxes between the surface and the atmosphere. This includes the assessment of medium scale land-surface changes like desertification and biomass productivity. Examples of applications and data validations result from different investigations in the Mediteranean area. An appendix summarizes useful formulas of the evaluation of satellite data. Beside the presentation of research results the book will therefore also be of interest for newcomers in the field and satellite data users who like to understand in greater detail the generation and information content of remote sensing data.