Category Archives: Awards

David W Allan – The Allan Variance

The Allan Variance is perhaps the most famous of David W. Allan’s achievements, with its derivative for telecom:  TDEV, the Time Deviation.

In 1965, Mr. Allan’s Master’s thesis gave birth to what the world knows as the Allan variance, the efficient technique for characterizing the performance of clocks and for knowing how to optimally use them in time keeping, and for which he is best known.   Because the Allan variance is used in characterizing the performance of atomic clocks, it was used extensively to sort out the performance of atomic clocks used for GPS to meet the stringent specifications for that navigation and timing system.

World Recognition

David Allan is as well recognized in the field of time and frequency technology as any other figure in the world. He helped to develop our nation’s official time and frequency standards based on atomic clocks and wrote the algorithm for keeping time for the United States.  He spent many man-years helping in the actual development of GPS. He also helped other nations with their official time standards, as well as helping with International Atomic Time and Universal Time Coordinated (UTC), which is official time for the world as kept at the BIPM (International Bureau of Weights and Measures) in Paris.
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The IEEE Joseph F. Keithley Award Recipient

IEE Advancing Technology for Humanaity On June 27, 2017, I was notified that I have received the Joseph F Keithley Award By IEEE (Institute of Electrical and Electronics Engineers), the largest scientific publishing house in the world.  It will be presented to me some time in 2018. Last year I received their highest award last year, “For seminal work… regarding time determination, time prediction, time dissemination and timekeeping through contributions to atomic frequency standards, space-based navigation, time and frequency stability analysis, time-scale algorithms, and timekeeping devices.”

The Keithey Award  is more towards instrumentation.  My friend and colleague, Emeritus Professor Kam Lau of UC Berkeley  kindly wrote the nomination for me.

The four main measurement instruments I am credited with inventing and building, and I assure you with lots of help from colleagues and mostly from on High, are:

1)      “Low information rate time control unit,” which is a quartz-crystal oscillator with instrumentation to automatically remove its systematic deviations, so that its output behaves more like an atomic clock.  This was used to generate time at Boulder for a while.

2)    A dual-mixer time-difference (DMTD) measurement system.  This is now the major means of comparing precision atomic clocks throughout the world.  We pushed the precision down to 50 femto-seconds, which is the time it takes light to travel about 15 microns.  A femto-second is one millionth of a nanosecond, which is one billionth of a second.

3)    We built a special GPS common-view timing receiver, which provided a means to compare atomic clocks around the world with a precision of about a nanosecond.  It became the main means of transferring time from the major timing centers around the world to the International Bureau of Weights and Measures (BIPM) in Paris for the generation of official time for the world, UTC, and is still being used today.  JPL funded the development because they needed it for the NASA/JPL Deep Space Network, which was in Goldstone, CA, Canberra, Australia, and Madrid, Spain.  I also installed one of these special receivers at the Arecibo Observatory in Puerto Rico for measuring millisecond pulsars.

4)    After retirement in 1992, Hewlett-Packard hired me as a consultant to use a “Smart Clock” patent that I had developed along with a GPS filtering idea so that by utilizing a high-quality quartz-crystal oscillator, special instrumentation and an algorithm, it made the output look like an atomic clock synchronized to UTC.  We tested it by showing that we kept synchronized with a full-up military receiver to 1 ½ nanoseconds for a month.  This was used for cell-phone sites to be synchronized, so that wherever you went your cell phone would have synchronism in timing from the different cell towers.  HP sold millions of dollars of these throughout the world.

Among those who built America’s biggest test and measurement companies after World War II are William Hewlett and David Packard of Hewlett-Packard Co. Howard Volium of Tektronix Inc. John Fluke Sr. of John Fluke Manufacturing Co. Inc. and Joseph F. Keithley of Keithley Instruments, Inc.

The Joseph F. Keithley Award is for Advances in Measurement Science

To recognize physicists who have been instrumental in the development of measurement techniques or equipment that have impact on the physics community by providing better measurements. The prize consists of $5,000 and a certificate citing the contributions made by the recipient. It is presented annually, which will be awarded in 2018.

Establishment & Support

This award is endowed by Keithley Instruments, Inc. and the Topical Group on Instrument and Measurement Science (GIMS).  Joseph F. Keithley made outstanding contributions and numerous accomplishments in area of sensitive and precision instrument development and measurement techniques.

I am grateful the Lord has allowed me to serve as I have.  I have been greatly blessed.  I know of myself I am nothing.  With Him I can do all things well with a goal to serve.

David W. Allan

The IEEE Highest Scientific Award – David W Allan

Davids awardThe IEEE (Institute of Electrical and Electronics Engineers) is the biggest scientific publishing house in the world, and the special issue celebrating the 50th year of the Allan variance came out 4 April 2016 is an awesome issue. They had three guest editors for it along with the regular editor.

All by itself, I felt greatly honored by the nomination letter submitted by the who’s who in international time and frequency to the IEEE, let alone be chosen to receive their highest award in recognition of my work.

On May 10th, 2016, my wife, Edna,  and I  had an amazing experience in Nor’lens (New Orleans). This annual symposium was the 70th providing for the international community the best in atomic-clock and precision timing research results.
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Celebrating the 50th Anniversary of the Allan Variance

250px-David_W._Allan,_croppedI just received word of the publication of a “Special Issue on Celebrating the 50th Anniversary of the Allan Variance.”

On May 10th, I will be received the highest award IEEE gives at an an international meeting (International Frequency Control Symposium) in New Orleans, LA, on the 10th of May for my life-long contributions.  The citation reads, “For seminal work to the UFFC community regarding time determination, time prediction, time dissemination and timekeeping through contributions to atomic frequency standards, space-based navigation, time and frequency stability analysis, time-scale algorithms, and timekeeping devices.”
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