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David W Allan – IEEE Joseph F. Keithley Award

David W AllanLast Wednesday, 23 May 2018, David W. Allan received the IEEE Joseph F. Keithley Award in Instrumentation and Measurement at the International Frequency  Control Symposium in Squaw Creek, CA.  The citation read, “for leadership in time determination and precise timing instruments.”

Atomic Clocks

Keeping time, or more precisely, keeping accurate time, has been the focus of David W. Allan’s career. He developed a device to automatically remove systematic timing errors from quartz-crystal oscillators used for generating the United States’ official time. He also created a dual-mixer time-difference measurement system with sub-pico-second precision for comparing atomic clocks.

GPS Receiver

His group developed a GPS common-view timing receiver, which has been used to transfer time from timing centers around the world to the International Bureau of Weights and Measures for generating coordinated universal time (UTC) as the world’s official time. This receiver was also used in synchronizing the NASA/JPL Deep Space Network high precision clocks.  His “smart-clock” method for enhancing GPS civil signals has been instrumental in synchronizing cell phone towers. The Allan Variance, Modified Allan Variance, and the Time Variance, which he developed, have become international standards for designing and constructing time and frequency equipment for systems like GPS, navigation, and telecommunication.
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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