“Access to Assured and Accurate Time II” was the title of a workshop held by NIST on the 25th of March. The event was the day before the annual ATIS Workshop on Synchronization and Timing Systems (WSTS) in San Jose. If, like us, you weren’t able to attend, you can still view the presentations as they are available for free download here.

We scanned the presentations (of course not the same as being there and hearing the narratives) and found a number of things of interest. Here are a couple of our observations:

Timing and Electrical Grids – This has been an area of increasing focus for NIST over the last several years. The first NIST workshop on timing and the electric grid we attended two years ago had grid engineers asking some very basic questions about GNSS and timing. Questions the navigation community had answered decades earlier. It is clear from the presentations last month that study and understanding in this area has come along way since then. Three excellent presentations by Dan Rippon of Schweitzer Labs, Gerardo Trevino of the Electric Power Research Institute (EPRI), and Ya-Shian Li-Baboud from NIST, provide a lot of very useful information.

In other presentations – Arbiter Systems cautioned against using signal measurement as a way of combating spoofing, Trimble focused on week number rollover, and FSM Labs discussed getting time from multiple domains for financial networks. Orolia repeated the multi-domain idea along with suggesting a multi-layered protection model for GNSS signals, and NextNav described the timing performance of its metropolitan beacon system  “Primarily serving indoor and urban/suburban areas.”

Presentations by MITRE‘s Homeland Security Systems Engineering and Development Institute, DHS, and NIST were more abstract, posing questions and models that sought to aid thinking about the meanings of “Assured,” “Access,” and “Accurate.”

All are worthwhile reviewing for folks in the PNT community.  We are going to see about attending in person at the next one of these events.

The presentations can be downloaded here.

We understand that this workshop and others in the series are a part of a joint DHS/NIST effort to describe resilient GNSS receivers for use in critical infrastructure. DHS issued guidelines on this subject in 2017 or early 2018 (the document is undated and we found it in January of 2018), but that apparently did not meet the goal sought by this effort.