Wednesday’s Book Review: “GPS Declassified”

GPS DeclassifiedGPS 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.

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2 Responses to Wednesday’s Book Review: “GPS Declassified”

  1. While the Reagan Administration made a public statement about “opening up” GPS for civil use, there isn’t any evidence of an actual policy decision to that effect. It seems to have been mostly a PR stunt. It did serve as sort of a “policy marker” that had some impact on the internal policy debate on GPS. But one of the driving rationales for the 1996 Clinton GPS policy (the first of its kind) was to make an official policy statement that GPS was indeed dual-use, and clarify the civil/military relationship in providing GPS services.

    Several of the individuals who were involved in the system from early days, such as Parkinson, insist that GPS was always going to be dual-use from the beginning. They will point to the existence of a public, civil signal in the very first satellites as evidence of that. However, others insist that there never was a serious effort to develop a robust civil service until after the Reagan announcement and the subsequent Clinton policy.


  2. Hi Brian,

    Thanks for your contribution. We interviewed for the book Harry Sonnemann, who was Special Assistant for Electronics Office of the Assistant Secretary of the Navy (Research and Development) from 1968-1976 and was a member of NAVSEG (Navigation Satellite Executive Steering Group) for its entire existence (1968-1973?). As we recounted in chapter 5 of the book, Sonnemann mentioned that in 1970, there was a conflict between the military’s requirement that a navigation system be passive, not reveal a receiver’s position, and civilian aviation’s preference that it be active to facilitate tracking an airliner’s position. With an active system, situations such as the disappearance of Malaysia Airlines Flight 370 would be unlikely to occur. In a passage we did not use in the book, Sonnemann stated:

    When other military users balked at contributing funds to a potential system that
    has no on-orbit demonstrated performance data, expressions of interest
    from civilian applications were solicited. Although there was interest in
    the civilian community, it was to consider the merit only after the on-orbit
    system capabilities were verified. Consequently, it was pretty clear that
    the only customers that were willing and able to put up funds for a system
    that provided precision location information were the military to obtain the
    capability to “drop five bombs in the same hole” which, by the way, also
    must have sufficient accuracy to spare the nearby church. A wide range of
    military and potential civilian applications were identified, but those
    interested took a “wait and see” position, that is, when the system’s
    capabilities verified with on-orbit data and its limitations identified, these
    potential customers would include GPS as another option to their existing
    capabilities, but not before.

    Thus, civilian applications were considered prior to the establishment of the Joint Program Office in 1973, but the military was paying for the system and the specifications were established to meet its needs.

    Roger Launius mentioned the controversy about the relative importance of Timation and 621B to GPS. Some of the assertions about this can be resolved using documents we’ve posted in the resources tab on our website. Dr. Parkinson has claimed repeatedly, since at least 1983, that Timation was a two dimensional system. Documents which contradict him include:

    Page 10 of the last document shows four Timation satellites sending signals to an airplane, giving the receiver its three dimensional position and clock synchronization.
    A 1974 document signed off by Dr. Parkinson states on chapter 1 page 1 that Timation was a three dimensional system.

    These and other controversies about Timation and GPS can be settled by reviewing these documents.


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