2022 PTTI Distinguished Service Award

Presented to: Dr. Demetrios Matsakis

Citation: For improving the U.S. Naval Observatory’s Master Clock by a factor of five over two decades, while personally making many advancements to international timekeeping

As head of the USNO’s Time Service Department, Dr. Demetrios Matsakis doubled the number of its clocks, adding masers and four rubidium fountains––the most precise robust 24x7 measurement system built. This brought a corresponding improvement to GPS time used by billions worldwide. For robustness, he built up the USNO’s Alternative Master Clock, collocated with the GPS Master Control Station. He negotiated the first USNO/NIST MOU. His 170-odd publications cover timescales, statistics including the pulsar time-statistic Sigma-Z, biases, diurnals, correlations, closure, GPS, PPP, NTP, loran, TWSTT/TWSTFT, and two relativity tests. He has designed algorithms to steer clocks, including GPS clocks, and published a paper unifying two aspects of control theory. His work on uncertainties in UTC was adopted by the BIPM, along with his computer code; at ION/ PTTI 2022, he presented and published an update.

With Jonathan Hardis (NIST), Dr. Matsakis stopped an initial proposal by industry to cease synchronizing power lines to the UTC, pointing out its potential impact on alarm and wall clocks. A revised proposal was later rejected by the FERC citing, as its only reason, letters that Matsakis and Hardis wrote as private citizens.

Dr. Matsakis has served on numerous committees, was president of the International Astronomical Union’s Time Commission, co-organized four symposia involving time, and wrote four resolutions passed by the Consultative Committee for Time and Frequency (CCTF). He represented the USA on the leap second question in Geneva. At the 2022 CGSIC meeting, he advised on how to prepare for a negative leap second and presented a unique way to predict them. Additionally, Dr. Matsakis has created an extensive set of tutorials and is an editor for GPS Solutions.

Dr. Matsakis received his BS from MIT and his PhD from the University of California, Berkeley, both in physics.