A fascinating sector is emerging in the world of aviation. Unmanned aircraft systems (UAS) are re-defining aerial activities, and broadening the definition of what it means to be a pilot. Unmanned: Textbook for UAS Studies, shares that emerging world with its readers. Based on its parent publication, the award-winning From the Ground Up from which it shares content, Unmanned also delves into subjects that UAS operators must know in order to fly the systems that are their responsibility. These subjects include: Theory of Flight, Aerodromes & Airspace, Aviation Weather, Air Navigation, and Radio. Unmanned concludes with a comprehensive list of explanations, spanning several pages, of International Abbreviations & Terminology used in the UAS field.