Page 42 - Jan2013

Passings
Dick Stern
Acoustical Society of America Melville, New York 11747
Victor Charles Anderson
1922–2012
Victor Charles Anderson, a bril- liant underwater acoustician and engi- neer, died 3 November 2012 at his home in Alpine, California.
Anderson was born on 31 March 1922 to missionary parents in Shanghai, China. He grew up in a com- pound sheltered from the outside world at the Shanghai University and then at the Shanghai-American School. His family moved back to the US when he was nine years old. His father became President of Linfield College and then Redlands University, where he enrolled as an undergraduate.
Anderson majored in physics at
the University of Redlands. In an effort
to finish his studies in three years, he
enrolled in an acoustics summer
course taught by Leo Delsasso of the
University of California at Los Angeles
(UCLA), and this inspired his future
work. Completing his degree in 1943, he took a position at the University of California Radiation Laboratory during World War II. He was first assigned to work at Oak Ridge on the Calutron, the magnetic separation process for industrial scale uranium enrichment, and then at Los Alamos, working on pressure gauges installed to measure the blast energy. He witnessed the Alamogordo bomb test and inspected the test site soon afterwards.
After the war he enrolled at UCLA as a physics graduate student in 1946, and after a year in residence, he joined the Marine Physical Laboratory (MPL) in San Diego, part of the Scripps Institution of Oceanography. His Ph.D., completed in 1953, was entitled, “Wide Band Sound Scattering in the Deep Scattering Layer.” At the time it was understood that organ- isms present in the upper layers of the ocean produced strong scattering of sonar, but there were no models to calculate the strength of individual scatterers. Anderson’s simplified solu- tion, modeling the scatterers as fluid spheres, remains an important result to this day.
After completing his Ph.D., Anderson accepted a post-
doctoral fellowship at the Acoustics Research Laboratory of Harvard University working with Ted Hunt. While at Harvard, he designed and developed the DELTIC (DElay Line TIme Compressor) correlator, a method of sampling incoming sonar signals along with reference signals, compressing the samples in time, and comparing them by correlation. Up to this point, it had not been possible to conduct correlations in realtime. DELTIC was the first practical realtime correlator, and it was put to use in a range of applications including sonar, radar, and speech processing.
Anderson returned to MPL in 1955 and continued his research in acoustic signal processing and ocean engineering. While working at MPL, he invented the DIMUS (DIgital MUltibeam Steering) system, a compu-
tationally efficient method for beamforming acoustic arrays, allowing simultaneous directional reception of sonar signals. For simplicity the system used clipped processing; just the polarity of the signal was saved. In a random noise back- ground, discarding the amplitude results in loss of only about three decibels in processing gain, but it is much simpler to implement. A one-bit signal sent into a shift register allows for time delay, resulting in digital signal processing, well before the advent of modern digital electronics. DIMUS pro- cessing enabled Anderson to form 1500 beams in real time from the 720 element ADA (Acoustic Distribution Array) he designed, fabricated, and took to sea in the 1970s. The DIMUS system is still used in sonar systems on U.S. Navy ships and submarines.
Faced with the problem of installing large acoustic arrays on the seafloor, Anderson developed the Remote Underwater Manipulator (RUM). It was among the first undersea remote- ly operated vehicles and it used motors operating under ambient pressure in oil, with electronics in pressure cases. It was originally designed to go out to sea from the shore, on a
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