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Preface

The ability to navigate has been an essential skill for survival throughout human history. As navigation has advanced, it has become almost inseparable from the ability to tell time. Today, position, navigation, and timing (PNT) technologies play an essential role in our modern society. Much of our reliance on PNT is the result of the availability of the Global Positioning System (GPS) and the growing family of Global Navigation Satellite Systems (GNSSs). Satellite‐based navigation and other PNT technologies are being used in the many fast‐growing, widespread, civilian applications worldwide. A report sponsored by the US National Institute of Standards and Technology (NIST) on the economic benefits of GPS indicated that GPS alone has generated a $1.4 trillion economic benefit in the private sector by 2019, and that the loss of GPS service would have a $1 billion per‐day negative impact.¹ PNT has become a pillar of our modern society. Knowledge and education are essential for the continued advancement of PNT technologies to meet the increasing demand from society. That is the rationale that led to the creation of this book.

While there are many publications and several outstanding books on satellite navigation technologies and related subjects, this two‐volume set offers a uniquely comprehensive coverage of the latest developments in the broad field of PNT and has been written by world‐renowned experts in each chapter’s subject area. It is written for researchers, engineers, scientists, and students who are interested in learning about the latest developments in satellite‐based PNT technologies and civilian applications. It also examines alternative navigation technologies based on other signals and sensors and offers a comprehensive treatment of integrated PNT systems for consumer and commercial applications.

The two‐volume set contains 64 chapters organized into six parts. Each volume contains three parts. Volume 1 focuses on satellite navigation systems, technologies, and applications. It starts with a historical perspective of GPS and other related PNT developments. Part A consists of 12 chapters that describe the fundamental principles and latest developments of all global and regional navigation satellite systems (GNSSs and RNSSs), design strategies that enable their coexistence and mutual benefits, their signal quality monitoring, satellite orbit and time synchronization, and satellite‐ and ground‐based systems that provide augmentation information to improve the accuracy of navigation solutions. Part B contains 13 chapters. These provide a comprehensive review of recent progress in satellite navigation receiver technologies such as receiver architecture, signal tracking, vector processing, assisted and high‐sensitivity GNSS, precise point positioning and real‐time kinematic (RTK) systems, direct position estimation techniques, and GNSS antennas and array signal processing. Also covered are topics on the challenges of multipath‐rich urban environments, in handling spoofing and interference, and in ensuring PNT integrity. Part C finishes the volume with 8 chapters on satellite navigation for engineering and scientific applications. A review of global geodesy and reference frames sets the stage for discussions on the broad field of geodetic sciences, followed by a chapter on the important subject of GNSS‐based time and frequency distribution. GNSS signals have provided a popular passive sensing tool for troposphere, ionosphere, and Earth surface monitoring. Three chapters are dedicated to severe weather, ionospheric effects, and hazardous event monitoring. Finally, a comprehensive treatment of GNSS radio occultation and reflectometry is provided.

The three parts in Volume 2 address PNT using alternative signals and sensors and integrated PNT technologies for consumer and commercial applications. An overview chapter provides the motivation and organization of the volume, followed by a chapter on nonlinear estimation methods which are often employed in navigation system modeling and sensor integration. Part D devotes 7 chapters to using various radio signals transmitted from sources on the ground, from aircraft, or from low Earth orbit (LEO) satellites for PNT purposes. Many of these signals were intended for other functions, such as broadcasting, networking, and imaging and surveillance. In Part E, there are 8 chapters covering a broad range of non‐radio frequency sensors operating in both passive and active modes to produce navigation solutions, including MEMS inertial sensors, advances in clock technologies, magnetometers, imaging, LiDAR, digital photogrammetry, and signals received from celestial bodies. A tutorial‐style chapter on multiple approaches to GNSS/INS integration methods is included in Part E. Also included in Part E are chapters on the neuroscience of navigation and animal navigation. Finally, Part F presents a collection of work on contemporary PNT applications such as surveying and mobile mapping, precision agriculture, wearable systems, automated driving, train control, commercial unmanned aircraft systems, aviation, satellite orbit determination and formation flying, and navigation in the unique Arctic environment.

The chapters in this book were written by 131 authors from 18 countries over a period of 5 years. Because of the diverse nature of the authorship and the topics covered in the two volumes, the chapters were written in a variety of styles. Some are presented as high‐level reviews of progress in specific subject areas, while others are tutorials with detailed quantitative analysis. A few chapters include links to MATLAB or Python example code as well as test data for those readers who desire to have hands‐on practice. The collective goal is to appeal to industry professionals, researchers, and academics involved with the science, engineering, and application of PNT technologies. A website, pnt21book.com, provides chapter summaries; downloadable code examples, data, worked homework examples, select high‐resolution figures, errata, and a way for readers to provide feedback.

A comprehensive project of this scale would not be possible without the collective efforts of the GNSS and PNT community. We appreciate the leading experts in the field taking time from their busy schedules to answer the call in contributing to this book. Some of the authors also provided valuable input and comments to other chapters in the book. We also sought input from graduate students and postdocs in the field as they will be the primary users and represent the future of the field. We want to acknowledge the following individuals who have supported or encouraged the effort and/or helped to improve the contents of the set: Michael Armatys, Penina Axelrad, John Betz, Rebecca Bishop, Michael Brassch, Brian Breitsch, Phil Brunner, Russell Carpenter, Charles Carrano, Ian Collett, Anthea Coster, Mark Crews, Patricia Doherty, Chip Eschenfelder, Hugo Fruehauf, Gaylord Green, Richard Greenspan, Yu Jiao, Kyle Kauffman, Tom Langenstein, Gerard Lachapelle, Richard Langley, Robert Lutwak, Jake Mashburn, James J. Miller, Mikel Miller, Pratap Misra, Oliver Montenbruck, Sam Pullen, Stuart Riley, Chuck Schue, Logan Scott, Steve Taylor, Peter Teunissen, Jim Torley, A. J. van Dierendonck, Eric Vinande, Jun Wang, Pai Wang, Yang Wang, Phil Ward, Dongyang Xu, Rong Yang, and Zhe Yang. The Wiley‐IEEE Press team has demonstrated great patience and flexibility throughout the five‐year gestation period of this project. And our families have shown great understanding, generously allowing us to spend a seemingly endless amount of time to complete the set.

This project was the brainchild of Dr. James Spilker, Jr. He remained a fervent supporter until his passing in October 2019. A pioneer of GPS civil signal structure and receiver technologies, Dr. Spilker was truly the inspiration behind this effort. During the writing of this book set, several pioneers in the field of GNSS and PNT, including Ronald Beard, Per Enge, Ronald Hatch, David Last, and James Tsui also passed away. This set is dedicated to these heroes and all those who laid the foundation for the field of PNT.

Jade MortonFrank van DiggelenBradford ParkinsonSherman LoGrace Gao

Note

1 1 RTI International Final Report, Sponsored by the US National Institute of Standards and Technology, “Economic Benefits of the Global Positioning System (GPS),” June 2019.