If one relatively recent technology can claim to be truly ubiquitous in our modern world, it would probably be global navigation satellite systems (GNSS), among which the global positioning system (GPS) is the most well known. These systems provide us with highly accurate positioning and timing information that is used by a very wide array of applications ranging from positioning of land, sea, and air vehicles to communications, banking, stock market, and power grids. Yet, only a few people know how GNSS are operating and what would be the potential impact of their failure. This book aims to describe current GNSS as well as their future development from a high-level point of view. This book is thus appropriate for any audience, from students to engineers and scientists. Its structure is easy to follow, and its content only requires a minimal background in space technology. Published by Springer as part of the “Springer Briefs in Space Development” series, it is 110 pages long and provides material that may serve as an introduction to GNSS in a teaching context. The book includes eight chapters that progress from the description of GNSS to governmental policy issues.

Chapter 1 presents some information about involved parties, background, and the history of GNSS. Chapter 2 describes Doppler-based satellite positioning, telemetry, and data systems such as Argos and Cospas-Sarsat. These systems rely on two-way telemetry and enable data transfers from sea/ground transmitters located in remote places on Earth. The Argos system is presented in detail as well as several applications such as ocean data monitoring, wildlife, and fishing boat tracking. The Cospas-Sarsat is a satellite-aided search and rescue tracking system for locating ships, crashed planes, and people in distress. The need to maintain satellite tracking for several minutes, the non-global coverage, as well as the lack of elevation differences led to the development of the next generation of space positioning systems called precision navigation and timing (PNT) systems. Chapter 3 describes the first of these systems, namely the US NAVSTAR GPS, of which the first satellite was launched in 1978. This chapter presents the fundamentals of GPS operation (“four measurements” procedure); its control segment; its accuracy, including the dilution of precision (DOP); and its upgrades (new satellites GPS-III, new signals L2C and L5, and new military M-code). More recent GNSS from other countries are also presented: the Russian Glonass, the Chinese Beidou, the EU Galileo (not yet operational), and the Indian IRSS.

Chapter 4 describes augmentation systems designed to enhance the accuracy of the GPS. Differential GPS is presented, which uses a ground reference station for improving the position of ground vehicles and ships close to coasts. Space-based augmentation systems are also described such as the Wide Area Augmentation System (WAAS) in the US, the European Geostationary Navigation Overlay Service (EGNOS), the MSAS in Japan, and so on. Carrier-phase GPS technology, which enables centimeter-level accuracy, is explained. This chapter concludes with a section on market trends and major players. Applications of PNT systems are presented in chapter 5. Details are given for major applications concerning transportation systems (precision aviation, marine and space navigation, and ground vehicles), precision agriculture, timing for banks and stock markets, disaster management, medical tracking, and military and scientific applications. Finally, chapter 6 highlights some national and international governmental issues, such as frequency allocation, overlapping and spectrum issues, coordination between PNT organizations, and ethical issues regarding personal tracking and location-based services (LBS). A concluding chapter and a summary chapter make up the last part of the book.

The reader may suffer from the poor quality of most of the pictures, which renders them hard to read, and may also regret not having any references cited in the text. The book provides a very useful appendix containing all of the acronyms and another one providing selected websites. All in all, this book enables the reader to quickly discover a very interesting scientific field and technology without having to dive into a thick textbook on the subject. It fulfills its objectives as a brief introductory text. However, readers looking for in-depth technical and scientific explanations of GNSS will have to look elsewhere.