Experimental testing of the noise-canceling processor

Collins, Michael D.; Baer, Ralph N.; Simpson, Harry

doi:10.1121/1.3621059

Cited by 3 publications

(1 citation statement)

References 12 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Due to the phenomenon of multipath propagation, the acoustic field on a vertical array in a waveguide may contain much more information about the location of a source than would be received on an array located in free space [4], [5]. It may be possible to determine the location of a source even when the signal is buried in noise [6], [7], there is interference from multiple sources [8], and there are uncertainties in the sound speed and other parameters of the environment [9], [10]. Acoustic data from a vertical array may also be used to determine the layering and acoustic parameters of the sediment [11].…”

Section: Introductionmentioning

confidence: 99%

Applications of a Motion Compensation Stabilized Vertical Array of Hydrophones

Collins

2019

IEEE Access

Self Cite

View full text Add to dashboard Cite

When a vertical array of hydrophones is used to determine the location of a submerged acoustic source in the ocean, performance is limited by the quality of the data, especially when there is interference from ambient noise and other sources or when there are uncertainties in the parameters of the environment. High-quality data may be obtained by anchoring a vertical array on the seafloor, but this time-consuming approach does not allow frequent deployments and mobility. By using motion compensation to eliminate the vertical motion of an array that is deployed from a surface platform, it may be possible to obtain high-quality data with a rapidly deployable system. Other applications that could benefit from this capability include the geoacoustic inverse problem of estimating the parameters of the sediment and studying the effects of horizontal diffraction and horizontal multi-paths for global-scale problems.

show abstract

Section: Introductionmentioning

confidence: 99%

Applications of a Motion Compensation Stabilized Vertical Array of Hydrophones

Collins

2019

IEEE Access

Self Cite

View full text Add to dashboard Cite

show abstract

Localizing Submerged Acoustic Sources Under Adverse Conditions

Collins

Fialkowski

Lingevitch

2022

J. Theor. Comp. Acout.

View full text Add to dashboard Cite

This paper reviews various approaches for localizing submerged acoustic sources under adverse conditions. It is essential to obtain data of the highest possible quality when there are adverse conditions, such as uncertainties in the environment, source motion, and low signal-to-noise ratio. Focalization is an approach in which the source location and environmental parameters are treated as unknowns. Due to a parameter hierarchy in which source location outranks environmental parameters, there may be many realizations of the environment that bring the source into focus; the ambiguity in the environment can be an advantage if the primary objective is to localize the source. Environmental uncertainty is often associated with environmental complexity, which can be an advantage by reducing the ambiguity of the source location. Obtaining a high-quality estimate of the covariance matrix may be difficult when there is source motion, but the complexity of the received field from a moving source is another factor that can reduce ambiguity. It may be possible to localize a source that is buried in noise when an estimate of the noise covariance matrix is available. During the development of approaches for localizing submerged sources, much of the focus has been on one-dimensional vertical arrays. An extension of the multi-valued Bartlett processor to the case of a rectangular array was designed to take advantage of the extra dimension of the array and appears to have the potential to be the most powerful combination of hardware and signal processing to date.

show abstract

Selected Topics of the Past Thirty Years in Ocean Acoustics

Collins¹,

Turgut²,

Buckingham³

et al. 2022

J. Theor. Comp. Acout.

View full text Add to dashboard Cite

This paper reviews some of the highlights of selected topics in ocean acoustics during the thirty years that have passed since the founding of the Journal of Theoretical and Computational Acoustics. Advances in computational methods and computers helped to make computational ocean acoustics a vibrant area of research during that period. The parabolic equation method provides an unrivaled combination of accuracy and efficiency for propagation problems in which the bathymetry, sound speed, and other environmental parameters vary in the horizontal directions. The extension of this approach to cases involving layers that support shear waves has been an active area of research throughout the thirty year period. Interest in basin-scale and global-scale propagation was stimulated by the Heard Island Feasibility Test for monitoring climate change in terms of changes in travel time that occur as the temperature of the ocean rises. Diminishing ice cover in the Arctic, which is one of the consequences of climate change, has stimulated renewed interest in Arctic acoustics during the past decade. Reverberation is a challenging problem that was the topic of a major research program during the beginning of the thirty year period. An innovative approach for making it feasible to solve such problems was applied to data for reverberation from the seafloor and from schools of fish, and some of the findings were featured in Science and Nature. Source localization is one of the core problems in ocean acoustics. When applied on a 2-D array of receivers, an approach based on the eigenvectors of the covariance matrix is capable of separating the signals from different sources from each other, determining when this partitioning step is successful, and tracking sources that cross each other in bearing; one of the advantages of this approach is that it does not require environmental information or solutions of the wave equation. Geoacoustic inversion for estimating the layer structure, wave speeds, density, and other parameters of ocean bottoms has also been a topic of interest throughout the thirty year period.

show abstract

Experimental testing of the noise-canceling processor

Cited by 3 publications

References 12 publications

Applications of a Motion Compensation Stabilized Vertical Array of Hydrophones

Applications of a Motion Compensation Stabilized Vertical Array of Hydrophones

Localizing Submerged Acoustic Sources Under Adverse Conditions

Selected Topics of the Past Thirty Years in Ocean Acoustics

Contact Info

Product

Resources

About