David W Allan

David W. Allan
Born	(1936-09-25)September 25, 1936 Mapleton, Utah, United States
Residence	Fountain Green, UT, United States
Nationality	USA
Alma mater	Brigham Young University, University of Colorado
Known for	Allan variance, GPS, Gravity
Scientific career
Fields	Physicist, Metrology
Institutions	National Bureau of Standards / National Institute of Standards and Technology

David Wayne Allan (born September 25, 1936) is an American physicist and metrologist known for developing the Allan variance, a widely used statistical measure of frequency stability in clocks and oscillators. He spent his career in the Time and Frequency Division of the National Bureau of Standards (NBS, now the National Institute of Standards and Technology, NIST) in Boulder, Colorado, and made significant contributions to precise timekeeping and to the GPS system. In his later work he has developed and promoted his own ideas in physics, presented through his enterprise "Allan's TIME" as a "New Unified Field Theory" with a new model for gravity.

Biography

David W. Allan was born in Mapleton, Utah, on September 25, 1936. He received a B.S. degree in physics from Brigham Young University in Provo, Utah, in 1960, and an M.S. degree in physics from the University of Colorado in Boulder in 1965.

Allan joined the National Bureau of Standards in Boulder, Colorado, in 1960, working as a physicist in its Time and Frequency Division. He served as chief of the Time and Frequency Coordination Group from 1979 until 1992. During his career he also worked internationally, consulting for the United Nations Development Programme in New Delhi in 1981 and serving as a guest scientist in China in 1982. He retired from NIST in 1992 and afterward consulted for Hewlett-Packard from 1993 to 1997.

Allan resides in Fountain Green, Utah, where he lives in a solar-powered home of his own design.

Scientific contributions

Allan variance and metrology

In 1966, while working at the National Bureau of Standards, Allan introduced the M-sample variance and the two-sample variance to characterize the frequency stability of clocks and oscillators. The two-sample variance became known as the Allan variance (AVAR), and its square root, the Allan deviation (ADEV), is widely used in plots of oscillator stability. The method addressed a long-standing problem in which different measurement approaches did not agree, making it difficult to compare the specifications of different oscillators.

Allan later developed the Modified Allan variance (MVAR) in 1981 and the Time variance (TVAR) in the late 1980s. The Allan variance, Modified Allan variance, and Time variance were adopted as IEEE standards in 1988 (IEEE Standard 1139) and are used extensively in the time and frequency, navigation, and telecommunications communities. Allan variance can distinguish among different types of noise, such as white and flicker noise, that the conventional standard deviation cannot separate.

Allan also contributed to the development of precise timekeeping systems and to the accuracy of the GPS navigation system, applying statistical time-and-frequency methods to the comparison and steering of atomic clocks.

Alternative physics ideas

In his later work, Allan developed his own ideas in theoretical physics, which he presents through his enterprise "Allan's TIME" (Time Interval Metrology Enterprise) and its associated website. He describes this work as a "New Unified Field Theory" that incorporates a new model for gravity, and he has stated that he seeks to relate the fields of science and religion. These ideas are outside the scientific mainstream and are presented here neutrally as his own perspective.

Honors

• Silver Medal, U.S. Department of Commerce (1968)
• IR-100 Award, Industrial Research magazine (1976)
• I.I. Rabi Award, IEEE (1984)
• Honorary Fellow, Institute of Navigation (1999)
• Time Lord Award (2011)
• IEEE Joseph F. Keithley Award (2018)
• Fellow of the IEEE (2021)

External links

• David W. Allan on Wikipedia
• Allan's TIME (Time Interval Metrology Enterprise) — official website