Professor Emeritus, Physics & Astronomy
School of Physical Sciences
PH.D., University of California, Berkeley, 1978
B.S., Yale University, 1970
Phone: (949) 824-6619
Fax: (949) 824-2174
University of California, Irvine
4130 Frederick Reines Hall
Mail Code: 4575
Irvine, CA 92697
Segmented-mirror telescopes, optical alignment, wavefront sensing
Professor Chanan received his B.S. degree in Mathematics and Physics from Yale University, and his Ph.D. (1978) in Physics from the University of California at Berkeley. He taught at Columbia University, where he also served as principal scientist for a solar-X-ray experiment which was flown on board the Space Shuttle in March of 1982 - one of the first successful Shuttle-borne scientific experiments. Dr. Chanan moved to UCI in 1985 to join a large team of UC and Caltech scientists working on the Keck Ten Meter Telescope. Wavefront sensing involves mapping out the surface of constant phase for a large optical system, such as a telescope. Such techniques are essential to the proper functioning of the large new technology telescopes, such as the Keck Ten-Meter, as well as for the optimization of older instruments, such as the Hale Five-Meter Telescope on Mount Palomar, especially with the advent of adaptive optics, in which one corrects for the blurring effects of the earth's atmosphere in real time. The research group has refined and extended existing wavefront sensing techniques for the Keck Telescope, improving the accuracy (wavefront surface measurement uncertainty divided by aperture diameter) to better than 1 part in 100 million, and generalizing from the geometrical to the physical optics regime, and is currently working on the design of the proposed Thirty Meter Telescope, an international collaboration involving the US, Canada, China, India, and Japan.
G. A. Chanan, C. Ohara, and M. Troy, "Phasing the mirror segments of the Keck telescopes II: the narrow-band phasing algorithm," Appl. Opt. 39, 4706-4714 (2000).
G. A. Chanan and M. Troy, "Strehl ratio and modulation transfer function for segmented mirror telescopes as functions of segment phase error," Appl. Opt. 38, 6642-6647 (1999).
G. A. Chanan, M. Troy, F. G. Dekens, S. Michaels, J. Nelson, T. Mast, and D. Kirkman, "Phasing the mirror segments of the Keck Telescopes: the broadband phasing algorithm," Appl. Opt. 37, 140-155 (1998).