“Everyone in the developed world needs precise time, all the time, whether they know it or not” according to Dr. Marc Weiss. “It is a foundation of every networked technology, digital broadcast, and most navigation systems, to name just a few critical uses.” Weiss is an internationally recognized expert on timing and synchronization and is a co-author on the recently released white paper “A Resilient National Timing Architecture.”
Three Paths to Precise Time
“Precise time is so important that everyone needs at least three independent methods of getting it. So, if one, or even two, fail it is not a national disaster.” said Dr. Pat Diamond, also a co-author of the paper.
“Our proposed architecture calls for precise time via GNSS (Global Navigation Satellite Systems), terrestrial eLoran broadcasts, and fiber.” Diamond is a long-time network designer, developer, and entrepreneur. He is also a member of the US National Space Based Positioning, Navigation, and Timing Advisory Board.
Diamond also points out that these three methods should be the backbone for timing distribution in the US, but won’t be the only methods. “What we are describing is a baseline architecture that will be added to” he said. “It is a starting point. We envision in the paper additional distribution methods like time from other satellites, user clocks, and so on, all being part of the mix.”
The federal government has a leadership interest and responsibility in all of this, according to the paper. Nations have long recognized the military and commercial advantages of determining and distributing precise time. Great Britain’s “Longitude Act” of 1714 was really about developing a chronometer to
support safe navigation of Royal Navy and British merchant fleet. In the United States the US Naval Observatory has been keeping and distributing a national time scale time since 1845.
“Just because the feds have an important leadership role, doesn’t mean they have to build and own a bunch of systems,” said Mr. Dana A Goward, the paper’s third co-author. “There are a variety of ways these systems can be established. Public-private-partnerships, subscription contracts like the FAA did with their air traffic ADS-B system, and cooperative agreements are all examples.”
The National Timing Resilience and Security Act of 2018 requires the US Department of Transportation to establish a terrestrial system to backup GPS timing services by December of this year. While the department does not appear to be on track to meet that goal, it completed a technology demonstration
program for GPS backup technologies earlier this year. Two companies demonstrated timing distribution by fiber. Another two demonstrated eLoran.
Many Pieces Already in Place
One of the benefits of the proposed architecture is that much of what is called for is already in place, according to the paper.
“We already have fiber networks, NAPs (network access points). eLoran is
mature and has been deployed by the Brits. And the US government owns enough former Loran-C sites to establish a nationwide eLoran network,” said Dr. Pat Diamond. “All we need is a bit of money and some engineering work to put this all together.”
The whitepaper “A Resilient National Timing Architecture” was sponsored by the Resilient Navigation and Timing foundation and is available on their website.