Worry about PNT and national security, not just eLoran

Letter to the Editor

February 2022

In November’s issue of GPS World, Editor-in-Chief Matteo Luccio opined that eLoran is part of the solution to GNSS vulnerability.

In January’s issue, he listed 10 questions from a PNT expert perhaps unfamiliar with eLoran.

These are important questions that must be asked of any technology, especially one under consideration to augment and back up our essential, but very weak and vulnerable, GNSS signals.

Yet the expert’s concerns pale in comparison to the essential questions about GNSS and PNT facing the United States and the West.

While I look forward to answers to the “10 questions” as a part of our ongoing professional dialogue, there are two important points of context we all need to keep in mind.

A Broad Consensus

First, Mr. Luccio’s assertion about eLoran being a part of the solution is more than reasonable. It also has a lot of impressive support from a wide variety of authoritative sources.

In 2008 and 2015, after much study each time, the U.S. government decided on and committed to building eLoran systems. Also, the U.S. government-sponsored National Space-based Positioning, Navigation and Timing (PNT) Advisory Board recommended eLoran in 2010 and 2018 as a part of securing the nation’s critical PNT capability.

In 2021, the U.S. Department of Transportation told Congress that wide-area terrestrial broadcast was a necessary part of a national PNT architecture. They later commented that infrastructure required per coverage area would be a key selection criterion for that broadcast technology. In other words, a system like eLoran.

Overseas, support for Mr. Luccio’s statement on eLoran is even stronger.

• The United Kingdom has long endorsed eLoran and operates an eLoran transmitter as a timing reference.
• Russia operates Chayka, a version of Loran.
• Available information points to Iran’s terrestrial PNT system being a form of Loran or eLoran.
• China and South Korea have long had Loran-C systems, and both are in the process of upgrading to the eLoran standard.

Each of these countries has publicly announced that it operates Loran/eLoran as a matter of national security in case space-based systems are jammed or destroyed, and to generally avoid overdependence on space-based PNT signals.

So, Mr. Luccio’s assertion was not at all revolutionary. Given all the studies, recommendations and existing uses, it would be surprising if he did not consider eLoran a part of the solution.

The Important Questions

Second, modern keying, encryption, authentication and other tech advances will help make all PNT technologies much safer and more resilient than they would have been decades ago, Loran and eLoran included.

Yet all will still have their strengths and weaknesses.

The most important questions we must ask are about how to establish the right level of national PNT security. These include:

• What is the right combination of technologies and systems with different delivery and failure modes that complement and reinforce GNSS and each other?
• How can the systems be efficiently and effectively implemented?
• How can the services they provide be easily accessed and widely adopted to ensure all parts of society are protected?

Countries such as China have answered these questions and are well down the path to implementation and wide adoption. Their robust national PNT architectures support easier rollout of 5G, rural broadband and other systems. They also serve as solid tech infrastructure upon which to build myriads of technologies and applications yet to be conceived.

Those nations not so advanced must accelerate their efforts. Otherwise, they must resign themselves to perpetually coping with GNSS vulnerabilities, including the possibility of attacks, and an eventual second or third place in the world because of their shortsightedness.

Dana A. Goward, President
Resilient Navigation and Timing Foundation