Letter to the editor: GPS backup need urgent — but avoid costly, narrow fix

OPINION:

Lorin Selby is right: America must strengthen its positioning, navigation and timing (PNT) infrastructure (“America’s GPS vulnerability threatens defense strategy,” Web, May 15). But the solution Mr. Selby calls “a smart hedge” — NextNav’s terrestrial system — will not accomplish the task.

As the former commander of U.S. Air Force Space Command, I’ve spent much of my career focused on the security and resilience of space-based systems. GPS is a marvel — but it’s also a single point failure for many of its uses. We do need a backup. However, building that resilience requires more than just good intentions. It demands systems that are geographically comprehensive, technically sound and resistant to disruption.

NextNav’s approach depends on repurposing spectrum heavily used by unlicensed devices and operating a proprietary signal in a crowded band. That’s a recipe for interference, not resilience. It also relies on dense 5G infrastructure to achieve coverage — an unrealistic and costly requirement in hard-to-reach areas, including those most in need of redundancy.

Fortunately, America has other terrestrially based options — proven technologies like eLoran, broadcast-based systems and facility-based timing solutions that don’t require reengineering the spectrum landscape.

The need is urgent, but the Federal Communications Commission should not rush toward an expensive, narrow solution. National resilience demands a layered, proven, and truly nationwide approach to GPS backup — one grounded in technical strength, broad coverage and thoughtful coordination.

GEN. WILLIAM SHELTON

Commander, U.S. Air Force Space Command (retired)

Member, National Space-Based PNT Advisory Board

Colorado Springs, Colorado