GPS III - Misleading Sound Bites Harm Nation

By Dr. Gene McCall
Delta IV GPS III Magellan rocket launched from Cape Canaveral Air Force Station, Florida.

Air Force photo by Airman 1st Class Dalton Williams

GPS III is an essential system that must be fully funded. Its signals are essential to military operations and civil society. We must ensure the constellation of satellites is as modern and robust as possible, preserving GPS as the “gold standard” for global navigation satellite systems.

At the same time, overselling GPS III’s improvements minimizes ongoing and serious risks to the nation and undermines other efforts for needed improvements.

Unfortunately, overselling seems to be an increasing problem.

For example, an industry journal quoted a senior Harris Corp. executive as touting GPS III’s “stronger signal.” The stronger signal will presumably be easier to receive, work in more locations and be more difficult to disrupt.

Yet this improvement in strength will hardly make a difference. Military GPS III users might receive a signal four times stronger than today, but that will still be very weak.

Civilian users will see signals that are — at best — about the same strength as they get today.

Another favorite sound bite for GPS III advocates is that it will be “three times more accurate” than today. While this sounds like a great improvement, it is unlikely to benefit most users. Today’s users get an average accuracy of about 28 inches. A three-fold improvement will bring that to about nine inches. It’s not something that will benefit most people very much.

Users who need more accuracy already have a variety of ways to supplement GPS signals and bring accuracy down as far as a centimeter or two. With GPS III they will likely still need to use those techniques, especially as the Air Force is unlikely to guarantee accuracy of better than a meter or two.

Another selling point is that GPS III signals will be eight times more difficult to disrupt.

GPS signals are essential to a vast array of critical infrastructure, transportation and emergency services applications. Signal disruption by U.S. adversaries, terrorist groups, criminals and ordinary people who don’t want to be tracked are on the rise.

So, when an Air Force general told CBS News last year that GPS III will be “eight times more jam resistant” than today’s GPS, it gave the impression that the government had the matter well in hand.

Nothing could be further from the truth.

The “eight times” sound bite is exceptionally misleading in two ways.

First, military coded GPS III signals will still be incredibly weak compared to the strength of the signals commonly used to disrupt them. Rather than an eight-fold improvement, GPS III would have to improve by a factor of 10 million to begin defeating the threat.

Second, “eight times more resistant to disruption” only applies to coded signals for military users with equipment that has not yet been built. The vast majority of GPS users and critical infrastructure will see no improvement at all.

While such misleading sound bites may help support funding requests for the expensive — and essential — GPS III program, they are harming national and homeland security.

Despite ongoing jamming of our military assets by Russia, China, Iran and others, many senior military and congressional leaders believe that GPS III and new receivers will eventually solve the problem.

This is completely untrue. Weak signals from space will always be easy to block. Even if this were not the case, adversaries would certainly be able to adapt during GPS III’s exceptionally long implementation period.

These false impressions have caused the Defense Department to give Alternate (or Assured) Positioning, Navigation and Timing systems little more than lip service. They are mentioned in strategies and research-and-development programs, but rarely elsewhere.

Misleading GPS III sound bites have also minimized — in the minds of many — the importance of a high-powered domestic, terrestrial system to augment and secure GPS signals. Such a system was mandated by President George W. Bush in 2004, and its impending implementation was announced in 2009 and again in 2015.

Yet entrenched in-space-only interests have managed to capture and control the narrative, preventing execution of these promises.

A terrestrial complement for GPS would likely cost America less than $50 million per year. This seems a substantial sum until one realizes that we already spend over $1 billion a year to maintain the space-based portion of GPS. And we have done so for 30 years.

More importantly, the cost of a terrestrial component becomes a paltry sum when compared to the billions in damage and lost productivity we will experience when space-based GPS signals, for whatever reason, are suddenly no longer available.

America is highly vulnerable. Adding a terrestrial component to GPS will make us nearly bulletproof.

A fairly inexpensive terrestrial system can act as both a backup for GPS and as an enhancement which can provide information to make the GPS even more accurate while essentially eliminating the jamming and spoofing threat.

Congress has recently made some tentative steps to forcing an unwilling bureaucracy to fulfill its long-standing commitment to do this.

But the “in-space-only” interests in the Pentagon and industry are well entrenched. Even more concerning, they seem either ignorant of — or indifferent to — the danger to the nation.

It is time for Congress to stop nudging and demand the administration protect GPS and protect the nation. 

Dr. Gene McCall retired as the chief scientist for Air Force Space Command at Peterson Air Force Base. He also served as chair of the Air Force Scientific Advisory Board and as a fellow at Los Alamos National Laboratory.

Topics: Space