APL-UW Home

Jobs
About
Campus Map
Contact
Privacy
Intranet

Dan Rouseff

Affiliate Scientist

Email

rouseff@apl.washington.edu

Phone

206-685-3078

Research Interests

Applied Electromagnetics and Acoustics, Wave Propagation and Scattering in Random Media Theory, Acoustic Imaging and Tomography

Department Affiliation

Acoustics

Education

B.S. Electrical Engineering, Washington State University, 1983

M.S. Electrical Engineering, Washington State University, 1984

Ph.D. Electrical Engineering, University of Washington, 1989

Publications

2000-present and while at APL-UW

The comparison of bottom parameter inversion in geoacoustic space and in (P,Q) space

Zhao, Z.D., E.C. Shang, and D. Rouseff, "The comparison of bottom parameter inversion in geoacoustic space and in (P,Q) space," J. Comput. Acoust., 25, 1750011, doi:10.1142/S0218396X17500114, 2017.

More Info

1 Jun 2017

The acoustic properties of the sea bottom can be described by geoacoustic (GA) parameters or by reflective parameters: P (phase shift parameter) and Q (absorption parameter). Both in GA space and in (P,Q) space, the parameters are difficult to measure and are instead estimated by inversion methods such as matched field inversion (MFI). In GA space, an assumed model is needed to mount the GA parameters for inverting (model dependent), while the reflective parameters (P,Q) are model-free. In this paper, the efficiency and quality of matched field processing (MFP) in GA space as well as in (P,Q) space are compared and the potential possibility of bouttom sound-speed-profile estimation is discussed.

On the sign of the waveguide invariant

Rouseff, D., and L.M. Zurk, "On the sign of the waveguide invariant," in Proc., OCEANS, 10-13 April, Shanghai, doi:10.1109/OCEANSAP.2016.7485368 (IEEE, 2016).

More Info

10 Apr 2016

Acoustic propagation in the ocean waveguide is characterized by mutual interference between the multiple ray paths connecting a source-receiver pair. In the Russian literature, these interference effects have been distilled mathematically into a single parameter, the so-called waveguide invariant defined as beta. The conventional wisdom is that the numerical value of beta is negative in deep water and positive in shallow water. In the present work, it is shown how the waveguide invariant can bifurcate and simultaneously have both positive and negative components. When bifurcation occurs, range-frequency mappings of acoustic intensity become fragmented. A method to separate the positive-beta components from the negative is sketched and applied to simulated data. Possible applications are discussed.

Modeling the effects of linear shallow-water internal waves on horizontal array coherence

Rouseff, D., and A.A. Lunkov, "Modeling the effects of linear shallow-water internal waves on horizontal array coherence," J. Acoust. Soc. Am., 138, 2256-2265, doi:10.1121/1.4930954, 2015.

More Info

1 Oct 2015

The coherence length of a horizontal array is the maximum separation between two points where coherent processing gives useful gain when a distant source is at broadside. In shallow water, the coherence length is limited by the environmental variability caused by several relevant oceanographic processes. In the present study, a statistical model is developed that quantifies how one oceanographic process, linear internal waves, affects the coherence length. A key input to the ocean sub-model is the vertically integrated energy density of the internal wave field. The acoustic sub-model is based on the adiabatic normal mode approximation and so should be reasonable for frequencies under 1 kHz. Numerical calculations using environmental data from the Shallow Water 2006 Experiment (SW06) show how the coherence length of individual modes varies with consequent effects on array coherence. The coherence length is shown to be a strong function of where the source and array are positioned in the water column. For a bottom-mounted array above a moderately lossy seabed, the model predicts a coherence length that depends only weakly on range, an effect observed in field experiments.

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
Close

 

Close