GPS Declassified: From Smart Bombs to Smartphones. By Richard D. Easton and Eric F. Frazier. Lincoln: University of Nebraska Press, 2013. Foreword by Rick W. Sturdevant. Illustrations, acknowledgments, abbreviations, notes, selected bibliography, index. Pp. xii – 301. ISBN: 978-1-61234-408-9. Hardcover with dustjacket. $34.95 USD.
It’s an age old problem. How do you know where you are on the Earth, in the air, or in the universe? Humans have been trying to solve that problem for eons, and some of the solutions are ingenious. GPS Declassified is an attempt to tell the fascinating story of space-based navigational systems. Originally established by the Department of Defense, the Global Positioning System (GPS) relies on 24 satellites in medium orbit around the Earth coupled with several ground tracking stations, and receivers on vehicles or with a hand-held device. It’s essentially a passive system, as receivers make contact with at least four satellites and triangulate positions. Coupled with computer aided systems this can provide real-time data about location, movement, altitude, and the like.
As Richard D. Easton and Eric F. Frazier make clear, spaceflight engineers realized very early the potential of this type of navigation system. In the latter 1950s scientists and engineers established that the Doppler shift of radio transmissions could help establish the location of a terrestrial receiving station. This became the basis of the U.S. Navy’s Transit satellite navigation system for SLBM submarines to improve missile accuracy. That system proved the concept, and there were even some civilian uses that emerged in the latter 1960s.
In addition, the U.S. Navy and the Air Force first competed and then collaborated on an approach called TIMATION (Time and Navigation) that used the precise timing of signals from numerous satellites to fix an accurate position. According to this book, it was TIMATION that formed the basis in 1973 of the NAVSTAR GPS (Navigation Signal Timing and Ranging Global Positioning System) program managed by the U.S. Air Force. Co-author Richard Easton has an ax to grind here, and he does so effectively. For years there has been a debate over who should receive credit for originating GPS. Roger Easton, the co-author’s father, was intimately involved in the TIMATION system and insisted that the Naval Research Laboratory and he were responsible for the GPS architecture. Brad Parkinson, the USAF officer who headed the project for his service, insisted that the lion’s share of the credit should go to the Air Force and himself. Richard Easton presents here a good defense of his father’s position.
Whether one cares about this debate over origins or not, the results of GPS have been profound. The first NAVSTAR satellites, launched between 1978 and 1985, transformed military navigation. I remember seeing aircraft tracked on a big screen in the Command Post using this system while historian at the Military Airlift Command (MAC) between 1987 and 1990. It was remarkable for all involved to be able to track the progress of every MAC aircraft worldwide 24/7.
Within a short time, in no small measure because of the shoot-down of flight KAL 007 in 1983 by the Soviet Air Force after the aircraft entered Soviet airspace, Ronald Reagan directed the extension of this capability to be available to everyone. Once this occurred, the civilian use of GPS exploded, with a huge range of applications, utilizing both the positioning and precision time signal capabilities of the system, becoming embedded in the civil and commercial infrastructure and the social fabric of everyday life. As the system became more capable, its uses widened. At present it is viewed as an indispensable resource for all manner of navigational needs. It has replaced printed maps as the navigational tool of choice for virtually everyone, and the fine art of map reading has become something of a lost art for a generation of children born since the 1980s.
Richard Easton and Eric Frazier offer in this book a solid basic history of the subject. As an introduction it is quite useful. It also seeks, in the authors’ minds, to correct what they view as errors and omissions in the GPS origins story. Finally, it tells quite a number of stories about the uses of GPS and how the technology has changed our lives, and then they go on to project possibilities for uses yet to be realized. This is a useful work about a complex topic. It is not the final word on the subject, however. Indeed, I don’t believe that a final word on anything can ever exist.