Some fundamentals of space technology - Satellites, surveillance and communications

During several decades, space-based functions have been integrated in almost all human activities, both civilian and military. Information gathering from space is widely accepted in all situations, military as well as security political. Within a network centric defence, the importance of obtaining, from space-based systems, information contributing to the common situation awareness is increasing in importance. Satellite communications will constitute a vital method, either as an alternative or as a complement, for maintaining communication in a network centric defence. Satellite navigation constitutes almost a necessity for international operations. In the report is explained, without going into details, some basic principles and notions (elements) when it comes to space technology concerning satellite orbits, how imaging is done from space, and something about communication and signals intelligence. The report treats satellite movements, imaging, communication, and signals intelligence. In several appendices, short explanations of concepts and terminology concerning satellites and sensors are given. There is also a list of frequently occurring abbreviations as well as tables of divisions of the electromagnetic spectrum.