The Global Positioning System (GPS) has revolutionized the measurement of position, velocity, and time. It has rapidly evolved into a worldwide utility with more than a billion receiver sets currently in use that provide enormous benefits to humanity: improved safety of life, increased productivity, and wide-spread convenience. Global Navigation Satellite Systems summarizes the joint workshop on Global Navigation Satellite Systems held jointly by the U.S. National Academy of Engineering and the Chinese Academy of Engineering on May 24-25, 2011 at Hongqiao Guest Hotel in Shanghai, China. "We have one world, and only one set of global resources. It is important to work together on satellite navigation. Competing and cooperation is like Yin and Yang. They need to be balanced," stated Dr. Charles M. Vest, President of the National Academy of Engineering, in the workshop's opening remarks. Global Navigation Satellite Systems covers the objectives of the workshop, which explore issues of enhanced interoperability and interchangeability for all civil users aimed to consider collaborative efforts for countering the global threat of inadvertent or illegal interference to GNSS signals, promotes new applications for GNSS, emphasizing productivity, safety, and environmental protection. The workshop featured presentations chosen based on the following criteria: they must have relevant engineering/technical content or usefulness; be of mutual interest; offer the opportunity for enhancing GNSS availability, accuracy, integrity, and/or continuity; and offer the possibility of recommendations for further actions and discussions. Global Navigation Satellite Systems is an essential report for engineers, workshop attendees, policy makers, educators, and relevant government agencies.

Since the wall dividing the Germanies came down, symbolically marking the end of the Cpold War, three new movements have become clear in the strategic planning of the more powerful nations: (1) regional issues are supplanting global ones; (2) roles and missions for the armed forces are changing; (3) the balnace between military and economic strength is shifting toward the economic. The United States is experiencing major changes in all three areas. With the third area in particular, U.S. planners urgently need new policies to exploit technological advantages in general, and the military use of civil space in particular. -- from Foreword, page ix.