Andrew (Andy) R. Chi
IN MEMORIAM
Andrew Chi died suddenly on June 19, 1982. During a three-decade career, he made important contributions to diverse areas of the time and frequency field - quartz crystal technology, atomic frequency standards and time dissemination via radio broadcast and satellite. A brief record of his career follows.
Andrew R. Chi was born in Tientsin, China on September 12, 1920. He received the B.S. degree in physics and mathematics from Western Maryland College, in 1944 and the M.A. degree in physics from Columbia University, in 1946. From 1946 to 1953 he was an instructor in physics at the Cooper Union School of Engineering in New York City.
In 1953 he joined the U.S. Any Signal Research and Development Laboratories, Fort Monmouth, as a physicist doing research on the fundamental properties of quartz. His findings contributed to the understanding and development of a method for determining the angle of cut of quartz resonator plates for various operating temperatures. He correlated the change of the resonator properties of quartz to the content of impurities introduced to the crystal structure of quartz during growth. For his findings, he was given a patent on growing synthetic quartz with controlled impurities. The crystals he made found applications as filters in communication equipment.
In 1957 he joined the Naval Research Laboratory, where he was engaged in studies of atomic resonance devices and precision frequency standards. He collaborated with physicists from the National Bureau of Standards in developing the atomic gas cell frequency standard using optical pumping techniques. He and his colleagues were the first to measure the hyperfine transition frequencies of rubidium-87 and cesium-l33 atoms. They were also the first to measure the frequency shift due to pressure and temperature of various buffer gases in a gas cell frequency standard. While at the Naval Research Laboratory he also maintained the proper operation of the cesium beam atomic frequency standard whose output frequency was measured in terms of Universal Time by astronomers and scientists at the U.S. Naval Observatory, Washington, D.C., and the National Physical Laboratory in Teddington, England.
In 1963 he joined NASA's Goddard Space Flight Center and became Head of the Timing Systems Section. In this position, he planned and conducted research and development of advanced timing systems for the manned and unmanned satellite tracking networks. Mr. Chi was the first to see the need for and became the prime mover in organizing a symposium for the purpose of defining the short-term frequency stability. This symposium was organized and held at Goddard Space Flight Center in November 1964. Because of the wide interest, the Institute of Electrical and Electronics Engineers (IEEE) joined the National Aeronautics and Space Administration (NASA) in sponsoring the Symposium on Short Term Frequency Stability. Mr. Chi was the Chairman of both the symposium and the Technical Program Committee. He was also the editor of the symposium proceedings.
During the planning stage of the Apollo program, he served as a member of the Apollo Navigation Working Group and designed the timing system for the Manned Space Flight Network. He served as a timing expert in the Geodetic Satellite Program; as a tracking scientist for the OMEGA Position Location Experiment, as Chairman of the Timing Standards Subcommittee of the Data Systems Requirements Committee; and was NASA's representative on the Timing Committee of DOD's Inter Range Instrumentation Group. His technical contributions during this period included NASA's time code standards and a time synchronization technique using dual very low frequency transmissions.
From 1971 to his death, Mr. Chi was a senior staff engineer of the Network Engineering Division. In this position he was responsible for planning and coordinating all programs pertaining to frequency and time for use by NASA's worldwide satellite tracking and data networks. He was the principal investigator of a joint experiment between NASA and the Federal Aviation Administration on precise time transfer via a synchronous satellite. He used the two-way time transfer technique to measure the round-trip propagation delay and demonstrated a system capability of transferring time to an accuracy of 50 nanoseconds.
He was the manager of a research technology operating plan on network timing and synchronization technology. As such he planned, developed, and coordinated time synchronization techniques for NASA users. He NASA in meetings with other Government agencies on matters pertaining to frequency control, atomic time synchronization, and time maintenance. He also represented the United States at international meetings for example in Study Group 7 of the International Radio Consultative Committee of the International Telecommunication Union.
He was a Fellow of the Institute of Electrical and Electronics Engineers, a member of the American Physical Society and a past member of the American Association of University Professors, American Association of Physics Teachers, Research Society of America, and Philosophical Society of Washington, DC. In addition to the Distinguished Service award, which he received in 1965, Mr. Chi was awarded the Scroll of Appreciation of the Secretary of State for his contributions to CCIR (1967), the Apollo Achievement Award (1969), the Skylab Achievement Award (1974), and the 1978 Moe I. Schneebaum Memorial Award for his significant contributions to the establishment of an international measure of frequency stability. He was given the 1980 Achievement Award by the Chinese Engineers and Scientists Association of Southern California for his contribution to international standards of frequency and time measurement.
CH1957-0/83/0000 0001 $1.00 @ 1983 IEEE
Mr. Chi was the Editor-in-Chief of the IEEE Transactions on Instrumentation and Measurement from 1978 to 1983. He received a B.S. degree in physics and mathematics from Western Maryland College, Westminster, in 1944, and an M.A. degree in physics from Columbia University, New York, in 1946. He continued graduate studies at Columbia University until 1947.
From 1946 to 1953 he was an Instructor in Physics at the Cooper Union School of Engineering, New York. In 1953 he joined the US Army Signal R&D Labs, Fort Monmouth, N.J., as a Physicist doing research in the fundamental properties of quartz. During 1957-1963 he was employed at the US Naval Research Lab, Washington, D.C., where he was engaged in research studies of atomic resonance devices and precision frequency standards. In 1963 he joined NASA's Goddard Space Flight Center, Greenbelt, M.D., and became Head of the Timing Systems Section, responsible for planning and coordinating all programs pertaining to frequency and time for use by NASA's worldwide satellite tracking and data networks. He was the principal investigator of a joint experiment between NASA and the Federal Aviation Administration on precise time transfer via a synchronous satellite. As such, he planned, developed, and coordinated time synchronization techniques for NASA users.
He was an IEEE Fellow, a member of the American Physical Society, and a past member of the American Association of University Professors, the American Association of Physics Teachers, the Research Society of America, and the Philosophical Society of Washington, DC. In addition to the Distinguished Service Award which he received in 1965, Mr. Chi was awarded the Scroll of Appreciation of the Secretary of State for his contributions to CCIR (1967), the Apollo Achievement Award (1969), the Skylab Achievement Award (1974), and the 1978 Moe I. Schneebaum Memorial award for his significant contributions to the establishment of an international measure of frequency stability.