Рональд Брэсуэлл: Ғалымның өмірі мен ғылыми еңбектері

Ronald Newbold Bracewell AO (22 July 1921 – 12 August 2007) was the Lewis M. Terman Professor of Electrical Engineering of the Space, Telecommunications, and Radioscience Laboratory at Stanford University.

Bracewell was born in Sydney, in 1921, and educated at Sydney Boys High School. He graduated from the University of Sydney in 1941 with the BSc degree in mathematics and physics, later receiving the degrees of B. E. (1943), and M. E. (1948) with first class honours, and while working in the Engineering Department became the President of the Oxometrical society. During World War II he designed and developed microwave radar equipment in the Radiophysics Laboratory of the Commonwealth Scientific and Industrial Research Organisation, Sydney under the direction of Joseph L. Pawsey and Edward G. Bowen and from 1946 to 1949 was a research student at Sidney Sussex College, Cambridge, engaged in ionospheric research in the Cavendish Laboratory, where in 1949 he received his PhD degree in physics under J. A. Ratcliffe.

From October 1949 to September 1954, Dr. Bracewell was a senior research officer at the Radiophysics Laboratory of the CSIRO, Sydney, concerned with very long wave propagation and radio astronomy. He then lectured in radio astronomy at the Astronomy Department of the University of California, Berkeley, from September 1954 to June 1955 at the invitation of Otto Struve, and at Stanford University during the summer of 1955, and joined the Electrical Engineering faculty at Stanford in December 1955. In 1974 he was appointed the first Lewis M. Terman Professor and Fellow in Electrical Engineering (1974–1979). Though he retired in 1979, he continued to be active until his death.

As a consequence of relating images to Fourier analysis, in 1983 he discovered a new factorisation of the discrete Fourier transform matrix leading to a fast algorithm for spectral analysis. This method, which has advantages over the fast Fourier algorithm, especially for images, is treated in The Hartley Transform (1986), in U. S. Patent 4,646,256 (1987, now in the public domain), and in over 200 technical papers by various authors that were stimulated by the discovery. Analogue methods of creating a Hartley transform plane first with light and later with microwaves were demonstrated in the laboratory and permitted the determination of electromagnetic phase by the use of square law detectors. A new elementary signal representation, the Chirplet transform, was discovered (1991) that complements the Gabor elementary signal representations used in dynamic spectral analysis (with the property of meeting the bandwidth duration minimum associated with the uncertainty principle). This advance opened a new field of adaptive dynamic spectra with wide application in information analysis.

Professor Bracewell was interested in conveying an appreciation of the role of science in society to the public, in mitigating the effects of scientific illiteracy on public decision making through contact with alumni groups, and in liberal undergraduate education within the framework of the Astronomy Course Program and the Western Culture program in Values, Technology, Science and Society, in both of which he taught for some years. He gave the 1996 Bunyan Lecture on The Destiny of Man. He was also interested in the trees of Stanford's campus and published a book about them. He also taught an undergraduate seminar titled I Dig Trees. Bracewell was also a designer and builder of sundials. He and his son Mark Bracewell built one on the South side of the Terman Engineering Building; after that building was demolished, a new home for the sundial, at the same orientation, was found on the Jen Hsun Huang Engineering Center. He built another sundial at the home of his son, and another on the deck of professor John G. Linvill's house. The Bracewell Radio Sundial at the Very Large Array was built in his honor.

Bracewell, Ronald N. and Pawsey, J. L., Radio Astronomy (Oxford, 1955) (also translated into Russian and reprinted in China)
Bracewell, Ronald N., Radio Interferometry of Discrete Sources (Proceedings of the IRE, January 1958)
Bracewell, Ronald N., ed., Paris Symposium on Radio Astronomy, IAU Symposium no. 9 and URSI Symposium no. 1, held July 30, 1958 – August 6, 1958 (Stanford Univ. Press, Stanford, CA, 1959) (also translated into Russian)
Professor Bracewell translated Radio Astronomy, by J. L. Steinberg and J. Lequeux, (McGraw Hill, 1963) from French
(NB. Second edition also translated into Japanese and Polish.) Bracewell, Ronald N., Trees on the Stanford Campus (Stanford: Samizdat, 1973)
Bracewell, Ronald N., The Galactic Club: Intelligent Life in Outer Space (Portable Stanford: Alumni Association, 1974) (also translated into Dutch, Japanese, and Italian)
(NB. Also translated into German and Russian.) Bracewell, Ronald N., Two Dimensional Imaging (Prentice Hall, 1995)
Bracewell, Ronald N., Fourier Analysis and Imaging (Plenum, 2004)
Bracewell, Ronald N., Trees of Stanford and Environs (Stanford Historical Society, 2005)