Inference regarding the state of mobile underwater object from a small aperture vertical array

2017 ◽  
Vol 142 (4) ◽  
pp. 2555-2555
Author(s):  
Abner C. Barros ◽  
Paul J. Gendron
Keyword(s):  
The State ◽  
Vertical Array ◽  
Small Aperture ◽  
Underwater Object

Applying double-difference methods for fine-scale acoustic tracking of controlled sources and sperm whales using a small aperture vertical array

2016 ◽  
Vol 139 (4) ◽  
pp. 2172-2172
Author(s):  
Ludovic Tenorio-Hallé ◽  
Aaron M. Thode ◽  
Jit Sarkar ◽  
Chris Verlinden ◽  
Jeffrey D. Tippmann ◽  
...  
Keyword(s):  
Double Difference ◽  
Fine Scale ◽  
Sperm Whales ◽  
Vertical Array ◽  
Acoustic Tracking ◽  
Small Aperture ◽  
Difference Methods

BROADBAND MATCHED-FIELD LOCALIZATION PERFORMANCE IN UNCERTAIN ENVIRONMENTS USING A SHORT ARRAY

2001 ◽  
Vol 09 (03) ◽  
pp. 957-972
Author(s):  
BRIAN F. HARRISON
Keyword(s):  
Water Environment ◽  
Low Frequency ◽  
Localization Algorithm ◽  
Vertical Array ◽  
Uncertain Environments ◽  
Small Aperture ◽  
Vertical Arrays ◽  
Field Localization ◽  
Performance Gains ◽  
Matched Field Localization

Typical applications of matched-field localization use low frequency signals received on large aperture vertical-arrays. However, small aperture arrays are much more practical for real-world systems and must be considered. Additionally, any practical localization algorithm must also be robust to environmental mismatch. In this paper, we present the broadband L∞-norm estimator for robust matched-field localization of mid-frequency signals (e.g., 800–4000 Hz) received on very short aperture vertical-arrays. Realistic simulation results are presented using broadband signals in the band of 1000–3000 Hz received on a 3 m vertical array which demonstrate the substantial performance gains in using the L∞-norm estimator over the asymptotically-optimal maximum a posteriori estimator and the conventional Bartlett processor. Experimental data results in an uncertain shallow-water environment using a 2.13 m vertical array in the band of 3000–4000 Hz are also presented.

Practical Picture Processing

1974 ◽  
Vol 32 ◽  
pp. 338-339
Author(s):  
T. A. Welton
Keyword(s):  
Radiation Damage ◽  
Coherence Length ◽  
Spatial Information ◽  
State Of The Art ◽  
Coherent Radiation ◽  
The State ◽  
Energy Spread ◽  
Electron Micrograph ◽  
Picture Processing ◽  
Molecular Skeleton

Various authors have emphasized the spatial information resident in an electron micrograph taken with adequately coherent radiation. In view of the completion of at least one such instrument, this opportunity is taken to summarize the state of the art of processing such micrographs. We use the usual symbols for the aberration coefficients, and supplement these with £ and 6 for the transverse coherence length and the fractional energy spread respectively. He also assume a weak, biologically interesting sample, with principal interest lying in the molecular skeleton remaining after obvious hydrogen loss and other radiation damage has occurred.

Pragmatic versus Morphological/Syntactic Criteria for Language Referrals

1980 ◽  
Vol 11 (2) ◽  
pp. 85-94 ◽  
Author(s):  
Jack Damico ◽  
John W. Oller
Keyword(s):  
Grade Level ◽  
The State ◽  
Verb Agreement ◽  
Remedial Programs ◽  
Service Training ◽  
Traditional Approaches ◽  
Communicative Effectiveness

Two methods of identifying language disordered children are examined. Traditional approaches require attention to relatively superficial morphological and surface syntactic criteria, such as, noun-verb agreement, tense marking, pluralization. More recently, however, language testers and others have turned to pragmatic criteria focussing on deeper aspects of meaning and communicative effectiveness, such as, general fluency, topic maintenance, specificity of referring terms. In this study, 54 regular K-5 teachers in two Albuquerque schools serving 1212 children were assigned on a roughly matched basis to one of two groups. Group S received in-service training using traditional surface criteria for referrals, while Group P received similar in-service training with pragmatic criteria. All referrals from both groups were reevaluated by a panel of judges following the state determined procedures for assignment to remedial programs. Teachers who were taught to use pragmatic criteria in identifying language disordered children identified significantly more children and were more often correct in their identification than teachers taught to use syntactic criteria. Both groups identified significantly fewer children as the grade level increased.

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