Semiclassical Investigation of Low Frequency, Long Range Acoustic Pulse Propagation in Deep Ocean Environments

1999 ◽  
Author(s):  
Michael Wolfson
Keyword(s):  
Long Range ◽  
Pulse Propagation ◽  
Acoustic Pulse ◽  
Low Frequency ◽  
Deep Ocean

Long‐range low‐frequency CW propagation in the deep ocean: Antigua‐Newfoundland

1974 ◽  
Vol 56 (1) ◽  
pp. 58-69 ◽  
Author(s):  
A. N. Guthrie ◽  
R. M. Fitzgerald ◽  
D. A. Nutile ◽  
J. D. Shaffer
Keyword(s):  
Long Range ◽  
Low Frequency ◽  
Deep Ocean

Low frequency acoustic pulse propagation in temperate forests

2015 ◽  
Vol 138 (2) ◽  
pp. 735-747 ◽  
Author(s):  
Donald G. Albert ◽  
Michelle E. Swearingen ◽  
Frank E. Perron ◽  
David L. Carbee
Keyword(s):  
Pulse Propagation ◽  
Temperate Forests ◽  
Acoustic Pulse ◽  
Low Frequency

NEAR-AXIAL INTERFERENCE EFFECTS IN LONG-RANGE OCEAN ACOUSTIC PULSE PROPAGATION

2008 ◽  
Vol 16 (02) ◽  
pp. 279-301
Author(s):  
NATALIE S. GRIGORIEVA ◽  
GREGORY M. FRIDMAN
Keyword(s):  
Long Range ◽  
Pulse Propagation ◽  
North Pacific Ocean ◽  
Acoustic Pulse ◽  
Three Dimensional ◽  
Realistic Model ◽  
Center Frequency ◽  
Sound Channel ◽  
The Time Domain ◽  
Dimensional Range

In many long-range ocean propagation experiments the source and receiver are placed close to the depth of the waveguide axis. In this case, rays emerging from the source at sufficiently small angles intersect the sound-channel axis many times and form in its vicinity a large number of caustics with caustics cusps located repeatedly along the axis. In neighborhoods of cusped caustics there exists a very complicated interference pattern. Neighborhoods of interference grow with range and at long ranges they overlap. As a result, a complex interference wave (axial wave), that propagates along the waveguide axis, appears. The goal of this paper is to obtain the representation for the axial wave in the time domain and calculate its magnitude for a realistic model of a three-dimensional range-independent medium. Numerical computations are done for the average profile from the Acoustic Engineering Test (AET) experiment. The pulse center frequency of 75 Hz with 30-Hz bandwidth is used that corresponds to broadband acoustic signals which were transmitted during November 1994 in the eastern North Pacific Ocean as a part of the AET. The propagation range is 3250 km. The sound source is located on the waveguide axis, and the receiver is placed close to the depth of the axis. Through numerical simulation the dependencies of the magnitude of the axial wave on depth of the receiver and propagation range are studied.

Autosub Long Range 6000: A Multiple-Month Endurance AUV for Deep-Ocean Monitoring and Survey

2021 ◽  
pp. 1-13
Author(s):  
Daniel Roper ◽  
Catherine A. Harris ◽  
Georgios Salavasidis ◽  
Miles Pebody ◽  
Robert Templeton ◽  
...  
Keyword(s):  
Long Range ◽  
Deep Ocean ◽  
Ocean Monitoring

Acoustic pulse propagation studies in the Gulf of Mexico

2005 ◽  
Author(s):  
J.W. Caruthers ◽  
V. Kamenkovich ◽  
N.A. Sidorovskaia ◽  
I. Udovydchenkov ◽  
G. Ioup
Keyword(s):  
Gulf Of Mexico ◽  
Pulse Propagation ◽  
Acoustic Pulse

Quantifying the Predictive Skill in Long-Range Forecasting. Part II: Model Error in Coarse-Grained Markov Models with Application to Ocean-Circulation Regimes

2012 ◽  
Vol 25 (6) ◽  
pp. 1814-1826 ◽  
Author(s):  
Dimitrios Giannakis ◽  
Andrew J. Majda
Keyword(s):  
Long Range ◽  
Ocean Circulation ◽  
Climate Models ◽  
Markov Models ◽  
Low Frequency ◽  
Model Error ◽  
Ocean Model ◽  
Coarse Grained ◽  
Predictive Skill ◽  
Relaxation To Equilibrium

Abstract An information-theoretic framework is developed to assess the predictive skill and model error in imperfect climate models for long-range forecasting. Here, of key importance is a climate equilibrium consistency test for detecting false predictive skill, as well as an analogous criterion describing model error during relaxation to equilibrium. Climate equilibrium consistency enforces the requirement that long-range forecasting models should reproduce the climatology of prediction observables with high fidelity. If a model meets both climate consistency and the analogous criterion describing model error during relaxation to equilibrium, then relative entropy can be used as an unbiased superensemble measure of the model’s skill in long-range coarse-grained forecasts. As an application, the authors investigate the error in modeling regime transitions in a 1.5-layer ocean model as a Markov process and identify models that are strongly persistent but their predictive skill is false. The general techniques developed here are also useful for estimating predictive skill with model error for Markov models of low-frequency atmospheric regimes.

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