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Bob Spindel

APL-UW Director Emeritus

Professor Emeritus Electrical Engineering and Adjunct Professor Emeritus, Oceanography






Dr. Spindel served as Director of the Applied Physics Laboratory from 1987 to June 2003. His research expertise is underwater acoustics; he has authored or co-authored over 100 scientific and technical publications, and has served as Chief Scientist on many research cruises.

Dr. Spindel was awarded the A.B. Wood Medal by the British Institute of Acoustics in 1981, the Gano Dunn Award from The Cooper Union in 1988, the Technical Achievement Award from the Institute of Electrical and Electronic Engineers (IEEE) Oceanic Engineering Society in 1990, and the Walter Munk Award by the Secretary of the Navy and the Oceanography Society in 2001. In 2003 he was awarded the Meritorious Civilian Service Award by the U.S. Navy. He is a Fellow of IEEE, the Acoustical Society of America, and the Marine Technology Society.

Department Affiliation

Director's Office


B.E. Electrical Engineering, The Cooper Union, 1965

M.S. Electrical Engineering, Yale University, 1966

M.Phil. Electrical Engineering, Yale University, 1968

Ph.D. Electrical Engineering, Yale University, 1971


2000-present and while at APL-UW

Calculation of the reverberation spectrum for Doppler-based sonar

Salin, B.M., M.B. Salin, and R.C. Spindel, "Calculation of the reverberation spectrum for Doppler-based sonar," Acoust. Phys., 58, 220-227, doi:10.1134/S1063771011050150, 2012.

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1 Feb 2012

For monostatic sonar using long pulsed tone signals, the problem of evaluating the spectrum of reverberation due to sound wave scattering by a rough sea surface is solved. Relatively simple computational schemes are proposed, which make it possible (i) to transform the three-dimensional spectra of surface waves to the frequency-angular characteristics of reverberation and (ii) to choose the optimal operating frequency band for a Doppler sonar from the point of view of reverberation. For typical wind wave characteristics measured in shallow water areas, the spectral levels of reverberation are estimated in the frequency band of acoustic signals within 0.4%u20132 kHz.

Investigation of the influence of wind waves on the spectral and angular characteristics of sea surface reverberation from a CW source

Salin, B.M., M.B. Salin, and R.C. Spindel, "Investigation of the influence of wind waves on the spectral and angular characteristics of sea surface reverberation from a CW source," In Proceedings, MTS/IEEE OCEANS 2010, Seattle, 20-23 September, doi:10.1109/OCEANS.2010.5664527 (MTS/IEEE, 2010).

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20 Sep 2010

This research is aimed at providing more reliable predictions of the characteristics of reverberation as a function of frequency and range, as well as propagation path and wind wave characteristics. A theoretical model is derived and is compared to experimental results which consist of simultaneous acoustic and wind wave characteristics measurements.

Experimental study of acoustic forward scattering on a marine shelf

Matveev, A.L. P.I. Korotin, V.I. Turchin, D. Rouseff, and R.C. Spindel, "Experimental study of acoustic forward scattering on a marine shelf," Proceedings, 3rd International Conference on Sensor Technologies and Applications, Athens, Greece, 18-23 June, 284-288 (2009).

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18 Jun 2009

The forward scattering of sound by a moving inhomogeneity can be observed when the inhomogeneity intersects a stationary path between an acoustic source and a receiving array. The scattered field is modeled as a weak perturbation of the direct signal when the inhomogeneity is near the direct path. Often the scattered field is masked by fluctuations in the direct signal. The task of a detection and parameter estimation of a moving inhomogeneity by the processing of acoustic signals as received on linear arrays is considered. After a review of methods, new experimental results are presented. The experiment was performed in the Bierke-Soond Strait of the Baltic in August 2006. The experiment geometry, propagation conditions, and spectra of direct signal fluctuations are discussed. Examples of experimental forward scattering observations obtained via various array-processing techniques are given. Good agreement between parameter estimates and true values is demonstrated for the intersection instant and the inhomgeneity's velocity, length and cross-sectional area. The minimum size of an inhomogeneity that can be observed is obtained.

More Publications

Acoustics Air-Sea Interaction & Remote Sensing Center for Environmental & Information Systems Center for Industrial & Medical Ultrasound Electronic & Photonic Systems Ocean Engineering Ocean Physics Polar Science Center