All Betz are on: A satnav book review

February 10, 2016 - By Don Jewell

In September 2013, the night before he won the prestigious ION Kepler Award, Dr. John Betz and I were enroute to an ION (Institute of Navigation) dinner when he casually mentioned that he was thinking about writing a book. The natural journalistic inquiries about subject and timing brought a surprising response. The draft of the first chapter was already complete and it would be about PNT space systems or GNSS (Global Navigation Satellites System) if you will. Not just GPS, but all space-borne (satnav) PNT (position, navigation and timing) systems and augmentations.

When I asked John exactly why he was writing the book he replied, “I am writing the book for several reasons. First, there is a shortage of books that uniformly treat all satnav systems, rather than emphasizing a single system. There are a lot of common and complementary characteristics that become clear when all are treated in a uniform and consistent way.

“Second, this is a chance to provide an integrated perspective on satnav systems engineering. Lastly, I’ve learned a lot in the last 17 years, and I want to document it in an organized way.”

I, of course, offered to help in any way I could. I mentioned that I would very much like to review the book when it was finished. Not too much was said about the book until the next year at the very same event, when John mentioned the book would be ready for publication in the first quarter of 2016. Again I offered to review the book, and this column is that promised review.

Engineering Satellite-Based Navigation and Timing: Global Navigation Satellite Systems, Signals, and Receivers

John W. Betz

ISBN: 978-1-118-61597-3

672 pages

December 2015, Wiley-IEEE Press

Hardcover print or ebook available

Qualifications

First of all, there can be no doubt that Dr. John Betz, a MITRE Fellow, is qualified to author this engineering tome about all matters pertaining to space-borne PNT. Indeed, if I were to fully recite his impressive curriculum vitae, it would be longer than the entire space allocated for my column, so I will make do with the short paragraphs that accompanied the Kepler Award.

Dr. John Betz, winner of the ION 2013 Kepler Award.

“Dr. John Betz contributed to the international interoperability and compatibility efforts leading to the design of the GPS L1C civil signal. His Binary Offset Carrier (BOC) technique is used for the GPS M-code signal, and adopted by satellite navigation systems developed by Russia, Europe, China, Japan and India.

“Since 1997, Dr. Betz has worked on the NAVSTAR GPS and also on international negotiations concerning compatibility and interoperability of GPS with the world’s satellite navigation systems. For his role in the United States/European Union negotiations that established compatibility and interoperability between GPS and Galileo in 2004, he received the U.S. State Department’s Superior Honor Award.

“More recently, Dr. Betz provided critical analysis related to GPS modernization, recommending affordable enhancements to address increasing threats and to shape the architecture of military GPS for decades to come. Col. Bernard Gruber, [then] director of the GPS Directorate said, ‘I can think of no one else in the past two decades, military or civilian, who has influenced this critical national asset to the same degree as Dr. Betz’.”

I asked Dr. Betz what he liked most about writing the book, what he disliked the most, and would he do it again?

“Don, some chapters just flew — it was really fun to write them,” he said. “And I really like the color graphics, even in the print edition. It was challenging to find the time, given my work schedule. That was probably the most difficult part. It’s amazing when I look back. It was a little more than two years from start to submitting the manuscript. I had planned on 400 pages and it’s 640 pages. And yes, I would do it all again.”

Scope

The scope of this engineering reference is exhaustive in nature where PNT is concerned. The work is balanced between original content and a compilation of academic papers by numerous expert authors. Certainly, Dr. Betz gives credit where credit is due; he often recommends other volumes, texts and papers for enlightenment. However, for me his personal and professional insights and clear explanations of highly technical issues are what make this a compelling volume.

In his introduction, Dr. Betz describes his effort:

“This book describes satellite-based navigation and timing (satnav), the engineering of systems that transmit radio frequency (RF) ranging signals from a constellation of satellites so that a passive receiver can determine time and its position. The intent of this book is to provide a consistent and integrated depiction of the engineering behind satnav.”

If a PNT or GNSS constellation, or even a small group of satnav vehicles, is in orbit today — such as WAAS, EGNOS and QZSS — John describes their makeup and contribution to the overall PNT solution in great detail that is understandable to both the academic and layman alike.

Insights

I have personally been involved with satnav in one fashion or another for 40 years. Frankly, I thought I was well versed in the subject. Yet, in every chapter of John’s book, I either learned something new or had an issue explained that I obviously did not understand quite as well as I thought. There is something for everyone interested in satnav in this wonderful book, regardless of their level of involvement or sophistication with PNT.

References

The book contains exhaustive tables, references, figures and formulas for all levels, which is why I am sanguine this book will become an invaluable reference and textbook for the military as well as any university dealing with educating students concerning satnav and PNT issues.

When I finished reading the 640-page volume, I had added more than 40 blue “stickies” to mark figures or tables for future reference.

This book is a treasure trove for PNT engineers and satnav experts, but it’s readability is such that even if you are only slightly curious about how space-based PNT works, you will find it an educational and enjoyable read.

For instance, on page 29, Table 2.1 summarizes the nominal constellation characteristics, 16 for each system, between GPS (US), GLONASS (Russian), Galileo (European) and the BeiDou (Chinese) constellations. While this will probably only serve as riveting cocktail repartee at something like an ION function, it is also just good to know, fun facts if you will. It might even serve as a Jeopardy category one day.

Bottom Line

Dr. Betz begins his lengthy but enjoyable tome with an explanation of satnav; takes the reader through the various space-borne PNT systems and augmentations on orbit today; describes the signals, the errors and the various pluses and minuses of each system; and then delves into PNT receiver design and describes how each signal is received and utilized.

After reading the book I asked Dr. Betz if he thought or hoped the book would be used as a textbook. He replied, “I hope it gets used in multiple ways. It can certainly be used by practicing engineers as a reference and for in-depth exploration. I hope its contents and structure make it useful as a textbook, because the book includes theoretical and applied questions at the end of many chapters that should help students learn how to extend and apply the theory and practice laid out in the book. Also, I hope its structure is conducive for use in teaching.”

While the jury is still out on whether this is a engineering textbook, a satnav reference manual, a primer on modernized PNT, or perhaps a compendium of all three, if you care at all about modern-day GNSS and all it enables, this book should be in your library.

Until next time, happy navigating, and I hope you enjoy the book.