Gernot Winkler

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  • 1988 I. I. Rabi Award
  • Life Span

    “An Expert on, and a Definer of, Time”
    Gernot Maria Rudolph Winkler ran the Time Service Department of the U. S. Naval Observatory (USNO) for thirty years, from 1966 to 1996. One of his first actions as Director was to replace a crystal clock with a cesium atomic clock as the USNO’s Master Clock, thus transitioning the Naval Observatory to the atomic clock era. From then on, under his leadership, the Time Service Department and the USNO grew and prospered. Under his tenure, his primary goals were to build a Master Clock system second to none, and to disseminate its time to the nation and the world. As an administrator, he secured funding for development, kick-start purchases, and operational use of a variety of innovations, such as 5071 cesiums, masers, mercury stored-ion clocks, and Two Way Satellite Time Transfer (TWSTT). This was done not only by incorporating the latest atomic clocks as they were developed, but also by increasing the number of clocks and applying sophisticated statistical techniques and computer technology to produce the time scale. He introduced time transfer by taking portable atomic clocks back and forth between locations, and later pioneered in applying GPS for that same purpose. He oversaw the improvement of the observational methods and determination of Earth orientation parameters by development of the world’s largest photographic zenith tube, a 26 inch PZT, and use of connected element interferometry, satellite laser ranging, and Very Long Baseline Interferometry observations and correlator for Earth rotation studies. This growth led to the establishment of the Earth Orientation Department at the USNO. One of his most politically difficult achievements was to convince the Air Force that the USNO should be the source of and monitor of time for the GPS system, and he also supplied UTC(USNO), the USNO Master clock’s realization of Coordinated Universal Time (UTC), as the source of time for the Loran and Omega Navigational Systems. In 1971, a collaboration between the USNO and Dr. Hafele of the University of Colorado provided a direct test of the relativistic time dilations by flying an atomic clock ensemble around the world in easterly and westerly directions. Later, a collaboration with Carroll Alley of the University of Maryland confirmed the isotropy of the speed of light by using the Washington Cathedral as a station to reflect microwaves between the USNO and NASA Goddard. His familiarity with relativity enabled him to make significant contributions to GPS’s treatment of the subject. Early in his career he co-founded the Precise Time and Time Interval (PTTI) Systems and Application Meetings. Starting from a small group of government agencies in 1969, it grew to be one of the core forums where practical timekeeping knowledge can be shared and discussed. The complete proceedings through 2012 can be found on-line on Starting with 2013, PTTI meetings have become part of the Institute of Navigation’s program, and now known as ION-PTTI. Gernot M. R. Winkler Dr. Winkler was also a leader in international organizations dealing with time. He served on numerous national and international boards and commissions. He led the International Consultative Committee for Radio communications (CCIR) activity in the definition of UTC with leap seconds in 1972, which established atomic time as the worldwide time standard. He also led International Astronomical Union (IAU) activities concerning the specifications of the determinations of time scales. To those in Time Service, Gernot was an inspiring leader in every way. A strong and supportive manager, aided by his “von-Braun” accent, he always encouraged his employees to do their best. One of his favorite techniques was to praise someone behind his back about something very specific, because he knew the word would get back to him/her. He would follow his employees’ progress, and would welcome them into his small, densely-packed but well-organized office to talk to them about it. As a role model Winkler, was an intellectual giant who was happy to share. He published at least 88 papers, covering all aspects of timekeeping from frequency standards to time transfer to statistics. Many learned timekeeping from his technical review articles, and very much enjoyed learning philosophy from his almost-as-technical essays on not just the nature of time but of such concepts as deism, determinism, realism, subjectivism, monism, and positivism. Some of these are available in the form of essays at his website His life before coming to the USNO Born in 1922, Gernot had an interest in astronomy from age 12, when he came across a book by German spaceflight pioneer Hermann Oberth. He was also influenced by the science fiction writer Jules Verne. As a youth he was a radio amateur proficient in Morse code, which enabled him to avoid front line duty when he was drafted, much against his will, to the German army. He spent seven years in the army, two of them as a prisoner of war in American custody in southern Italy. Returning to Austria in 1947, he immediately resumed his studies at the University of Graz. There his interests evolved toward the mathematical sciences, including geophysics, physics, and astronomy. His PhD. in 1952 was on the mathematical modeling of coupled electromagnetic cavities used to support the microwave engineering industry. He was also associated with the Astronomy Department’s Solar Observatory, Kanzelhoehe. Dr. Winkler came to the United States in 1956 and began work in the microwave resonance branch of the U. S. Army Signal Corps, Monmouth, NJ, where they were supporting work on the first atomic clocks, the Atomichron, for the National Radio Company. These devices had a stability of one part in 1011, and became the first commercially-produced frequency standards. He earned six patents for his personal contributions to maser and oscillator stabilization. He also worked on ionospheric radio transmission, organizing and participating in several expeditions to the Greenland ice cap, as well as Antarctica. Awards and Honors In 1970 he was elected a Fellow of the IEEE (Institute of Electrical and Electronic Engineers). In 1984 he was awarded the Presidential Rank Award for Meritorious Executive in the Senor Executive Service. In 1988 at the International Frequency Control Symposium, he was awarded the I.I. Rabi Award. In 1994, at the 26th Annual Precise Time and Time Interval (PTTI) Applications and Planning Meeting, he received the Distinguished Service Award. The award citations can be found at and here. Family Winkler was preceded in death by his beloved wife Renate Anna Franziska Winkler, née Strafella (Nov. 3, 1923 – March 31, 2014). He eulogized her at He is survived by his children Vic and Beatrice (Trixi) Winkler Summers. More Information The full transcript of Steven Dick’s interview with Dr. Winkler in 1989, undertaken as part of the U. S. Naval Observatory history, Sky and Ocean Joined(Cambridge, 2003), is available in the Observatory Library in Washington, D.C. Winkler’s award citations can be found at and here.

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