Remote Sensing is about the acquisition of data from radiation detectors installed in space platforms and their subsequent treatment to obtain information about our environment. It is a discipline based on measurable magnitudes and verifiable hypothesis that requires a good ability on analysing and synthesising and offers society direct results that improve our knowledge of the physical world. Within Remote Sensing, we can include meteorological products, applications directed to improve the farming performances, terrain's cartography, droughts' control and natural disasters, search of new mining sites, forest management, land use, and a long etcetera that has just began, due to the fact that it is a new and young discipline. The interest of society in the scientific studies based on Remote Sensing data on the most variable sides of our environtment is easily justified, taking into account the huge amount of operative applications that provide the scientific results obtained. Remote Sensing supplies thematic maps of our planet, interesting features and parameters related to water, ground, farming and natural vegetation, and they provide regular and updated information, ease the continuous and long-term monitoring, and help the managers of these fields in the decision making process. It establishes a way of study of no access areas and/or with minimum field support. Remote Sensing is also applied to studies on the outer space and contributes to a better understanding of the universe surrounding us.