An essential, introductory text for marine engineering students covering the fundamental earth-observation concepts that underpin all space-based terrestrial and maritime remote sensing methods. Satellite-based earth observation provides key weather and environmental information to all nations, including key maritime users such as navy, coastguard and merchant vessels. The application and understanding of electromagnetic wave-based devices and sensors is an established merchant sea service requirement, found in the Standards in Training and Certification in Watchkeeping (STCW95) qualification and various Maritime Coastguard Agency exams. It is vital that maritime and land-based users have a basic understanding of the concepts upon which these essential earth-observation systems now operate. The book is written as simply as possible to support the growing numbers of overseas students for whom English is not their first language. It provides a firm foundation prior to reading and studying of the Reeds Marine Engineering series, and is complementary to other volumes in the Introductions series. Maritime and land-based students and scientists having read this easy-to-read volume will be better prepared for more in-depth study.