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Striation-Based Beamforming For Estimating The Waveguide Invariant With Passive Sonar, Lisa M. Zurk, Daniel Rouseff
Striation-Based Beamforming For Estimating The Waveguide Invariant With Passive Sonar, Lisa M. Zurk, Daniel Rouseff
Electrical and Computer Engineering Faculty Publications and Presentations
The waveguide invariant summarizes the pattern of constructive and destructive interference between acoustic modes propagating in the ocean waveguide. For many sonar signal-processing schemes, it is essential to know the correct numerical value for the waveguide invariant. While conventional beamforming can estimate the ratio between the waveguide invariant and the range to the source, it cannot unambiguously separate the two terms. In the present work, striationbased beamforming is developed. It is shown that the striation-based beamformer can be used to produce an estimate for the waveguide invariant that is independent of the range. Simulation results are presented.
Extraction Of Small Boat Harmonic Signatures From Passive Sonar, George Lloyd Ogden, Lisa M. Zurk, M. E. Jones, M. E. Peterson
Extraction Of Small Boat Harmonic Signatures From Passive Sonar, George Lloyd Ogden, Lisa M. Zurk, M. E. Jones, M. E. Peterson
Electrical and Computer Engineering Faculty Publications and Presentations
This paper investigates the extraction of acoustic signatures from small boats using a passive sonar system. Noise radiated from a small boats consists of broadband noise and harmonically related tones that correspond to engine and propeller specifications. A signal processing method to automatically extract the harmonic structure of noise radiated from small boats is developed. The Harmonic Extraction and Analysis Tool (HEAT) estimates the instantaneous fundamental frequency of the harmonic tones, refines the fundamental frequency estimate using a Kalman filter, and automatically extracts the amplitudes of the harmonic tonals to generate a harmonic signature for the boat. Results are presented …