Letters to the Editor: The Other Shoe

March 23, 2010 - By GPS World Staff

The Other Shoe

I read Don Jewell’s column in the March Defense PNT newsletter (see www.gpsworld.com/othershoe), on the troubling concern about GPS dependency, with considerable interest. I thought he made some excellent points, and, in my capacity as a member of GPS World’s Editorial Advisory Board, I would like to present some further thoughts for consideration.

I thought Don was pretty fair with General Schwartz’ comments, including the thinly veiled reference to underlying Air Force (AF) motives toward a smaller GPS constellation. However, in addition to focusing on the comments of one senior individual, you might also give some thought to the actions and motives of many in both the civil and military communities who have not only failed to embrace but have also resisted the advancement of a National Positioning, Navigation and Timing (PNT) Architecture and the holistic management framework necessary to implement it.

After 2-plus years of work by 30-plus government agencies (military and civil), an enterprise-level view of the PNT Architecture was presented to the public at the ION conference in Savannah in 2008. Since that time, discussions regarding its implementation have proceeded very slowly within the government. The Architecture contains all the elements you identify as contributing to the “Perfect Handheld GPS,” though, at the enterprise level, many have not technologically matured to the necessary system-of-systems level that would permit acquisition decisions under government rules. As you know, that will take focused technical analysis and trade studies, as well as further development in some cases to bring promising technologies along. Commercial industry does it faster, but its solutions are in most cases unique and proprietary, and not necessarily applicable for use by government agencies, particularly the military.

You also advocate for more tightly integrated GPS capability, “resulting in impregnable GPS for all users.” That thought pervades the enterprise PNT Architecture, beginning with its foundational recommendation (that GPS remain the cornerstone) and extending through many of the 18 other recommendations which follow. In the Architecture, however, we put a slightly different twist on the objective of GPS integration.

We recognize that, while GPS service can be improved by increases in signal power, possible additional signal frequencies, and a larger constellation, GPS itself can never become “impregnable.” Rather, by integrating GPS with augmentations and complements of several different types, our objective is to create continuously available PNT of high precision and fidelity from a variety of sources without regard to which particular source(s) is/are contributing to the solution at any particular point. I like to refer to that as “cloud PNT” with a bow to the recent advancements in “cloud computing.”

Finally, with regard to eLoran, the PNT Architecture envisioned a place in 2025 for an evolved eLoran-type capability, recognizing the possible value of frequency diversity, higher power, signal penetration, carrying 2D position and precise time, all in a relatively low-cost government-provided LF/MF service. Of course, it would have had to compete with other technology alternatives, but that potential course now seems foreclosed. You make the point that the basis for eLoran is, of course, the Loran-C system whose operation was recently terminated by the Obama Administration.

The most troubling aspect of that termination was the statement in the Federal Register announcement that the DHS would continue an assessment to determine if a single, domestic system is needed as a GPS backup for critical infrastructure applications at the same time it determined that the continued operation of the viable backup represented by Loran was not necessary.

Go figure.

— Jules McNeff Editorial Advisory Board (since 1990), GPS World

The Spy

A prescient reader wrote a comment on the webpage of a recent story about the demise of Loran. See www.gpsworld.com/rtcm and scroll all the way down. It begins:

Tso had just installed the last of a series of innocuous-looking boxes in a field some miles to the west of New York City. . . . It, and the other 299 units like it, had a single purpose. It was so simple, and it had been handed like a gift to him by the U.S. government itself. . . . .