The progress in Earth Observation (EO) technology over the recent years has led to the launch of multispectral and hyperspectral EO sensors. The overall objective of this book is to quantify and model the existing interactions among the Soil, the Vegetation and the atmosphere using multispectral and hyperspectral sensors by targeting the following applications:The 1st app. Evaluate the accuracy of the evapotranspiration (ET) operational estimates from the Meteosat Second Generation (MSG) SEVIRI at a range of selected ecosystems in Europe.The 2ed app. Investigate the development of a suitable methodology for establishing and monitoring the indicators of Ecosystem Health (EH) and its responses to wildfire using Earth Observation (EO) data synergistically with GIS. The 3ed app. Estimate the potential role of combining field and laboratory spectroradiometric data with geochemical data to quantify and model Heavy Metals Soil Contamination (HMSC) and the 4th app. Examine the synergistic operation among Hyperion hyperspectral satellite imagery with SVMs, FRAGSTATS program and PCA in order to quantify the LULC changes in a model mediterranean ecosystem.