Download or read book Project Review on Geophysical and Ocean Sound Speed Profile Inversion written by N. Bleistein and published by . This book was released on 1984 with total page 24 pages. Available in PDF, EPUB and Kindle. Book excerpt: This report summarizes the status of the research projects on inverse problems at the Colorado School of Mines. We are engaged in two major projects in inverse problems: (I) inverse methods for reflector imaging; and (II) inverse methods for profile inversion in the ocean. In the first project we use 'high frequency' methods to invert backscatter (monostatic) observations. Our primary applications are to seabed mapping and seismic exploration although we have also implemented our method to image flaws in solids. Computer implementation of the current algorithm is discussed, and some indication of directions for extending the method is given. A unique feature of the second project is that the direction of variation of the sound speed profile (depth) is orthogonal to the direction of propagation (range). Again, high frequency methods are used and computer implementation is briefly discussed. Keywords include: velocity inversion Born Inversion, migration, stationary phase, singular function, and reflectivity function.
Download or read book Inverse Problems of Acoustic and Elastic Waves written by Fadil Santosa and published by SIAM. This book was released on 1984-01-01 with total page 384 pages. Available in PDF, EPUB and Kindle. Book excerpt: Contents: A Survey of the Vocal Tract Inverse Problem: Theory, Computations and Experiments; Convergence of Discrete Inversion Solutions; Inversion of Band Limited Reflection Seismograms; Some Recent Results in Inverse Scattering Theory; Well-Posed Questions and Exploration of the Space of Parameters in Linear and Nonlinear Inversion; The Seismic Reflection Inverse Problem; Migration Methods: Partial but Efficient Solutions to the Seismic Inverse Problem; Relationship Between Linearized Inverse Scattering and Seismic Migration; Project Review on Geophysical and Ocean Sound Speed Profile Inversion; Acoustic Tomography; Inverse Problems of Acoustic and Elastic Waves; Finite Element Methods with Anisotropic Diffusion for Singularly Perturbed Convection Diffusion Problems; Adaptive Grid Methods for Hyperbolic Partial Differential Equations; Some Simple Stability Results for Inverse Scattering Problems; Inverse Scattering for Stratified, Isotropic Elastic Media Using the Trace Method; A Layer-Stripping Solution of the Inverse Problem for a One-Dimensional Elastic Medium; On Constructing Solutions to an Inverse Euler-Bernoulli Beam Problem; Far Field Patterns in Acoustic and Electromagnetic Scattering Theory; Renaissance Inversion; On the Equilibrium Equations of Poroelasticity; GPST-A Versatile Numerical Method for Solving Inverse Problems of Partial Differential Equations; and Applications of Seismic Ray-Tracing Techniques to the Study of Earthquake Focal Regions.
Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1994 with total page 804 pages. Available in PDF, EPUB and Kindle. Book excerpt: Lists citations with abstracts for aerospace related reports obtained from world wide sources and announces documents that have recently been entered into the NASA Scientific and Technical Information Database.
Download or read book Full Field Inversion Methods in Ocean and Seismo Acoustics written by Orest Diachok and published by Springer Science & Business Media. This book was released on 2013-04-17 with total page 424 pages. Available in PDF, EPUB and Kindle. Book excerpt: Recent advances in the power of inversion methods, the accuracy of acoustic field prediction codes, and the speed of digital computers have made the full field inversion of ocean and seismic parameters on a large scale a practical possibility. These methods exploit amplitude and phase information detected on hydrophone/geophone arrays, thereby extending traditional inversion schemes based on time of flight measurements. Full field inversion methods provide environmental information by minimising the mismatch between measured and predicted acoustic fields through a global search of possible environmental parameters. Full Field Inversion Methods in Ocean and Seismo-Acoustics is the formal record of a conference held in Italy in June 1994, sponsored by NATO SACLANT Undersea Research Centre. It includes papers by NATO specialists and others. Topics covered include: · speed and accuracy of acoustic field prediction codes · signal processing strategies · global inversion algorithms · search spaces of environmental parameters · environmental stochastic limitations · special purpose computer architectures · measurement geometries · source and receiving sensor technologies.
Download or read book Mathematical and Computational Methods in Seismic Exploration and Reservoir Modeling written by William Edward Fitzgibbon and published by SIAM. This book was released on 1986-01-01 with total page 306 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Sound Speed Profile Inversion in the Ocean written by Linda Boden and published by . This book was released on 1985 with total page 166 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Mathematical Reviews written by and published by . This book was released on 1986 with total page 484 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book A Modal WKB Inversion Method for Determining Sound Speed Profiles in the Ocean and Ocean Bottom written by Kevin D. Casey and published by . This book was released on 1988 with total page 770 pages. Available in PDF, EPUB and Kindle. Book excerpt: Two approaches to determining the ocean sound profile using measured acoustic modal eigenvalues are examined. Both methods use measured eigenvalues and mode dependent assumed values of the WKB phase integral as input data and use the WKB phase integral as a starting point for relating the index of refraction to depth. Inversion method one is restricted to monotonic or symmetric sound speed profiles and requires a measurement of the sound speed at one depth to convert the index of refraction profile to a sound speed profile. Inversion method two assumes that the sound speed at the surface and the minimum sound speed in the profile are known and is applicable to monotonic profiles and to general single duct sound speed profiles. For asymmetric profiles, inversion method two gives the depth difference between two points of equal sound speed in the portion of the profile having two turning points, and in the remainder of the profile it gives sound speed versus depth directly. A numerical implementation of the methods is demonstrated using idealized ocean sound speed profiles numerical experiments used to test the performance of the inversions using noisy data. The two methods are used to determine the sediment sound speed profiles in two shallow water waveguide models, and inversion method one is used to find the sediment sound speed profile using data from an experiment performed in the Gulf of Mexico. Theses. (edc).
Download or read book Applied Mechanics Reviews written by and published by . This book was released on 1986 with total page 1072 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Mathematical and Numerical Aspects of Wave Propagation Phenomena written by Gary C. Cohen and published by Society for Industrial and Applied Mathematics (SIAM). This book was released on 1991 with total page 820 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book SIAM Journal on Scientific and Statistical Computing written by Society for Industrial and Applied Mathematics and published by . This book was released on 1987 with total page 704 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Sound Propagation through the Stochastic Ocean written by John A. Colosi and published by Cambridge University Press. This book was released on 2016-06-20 with total page 443 pages. Available in PDF, EPUB and Kindle. Book excerpt: In this book, key discoveries in the field of statistical ocean acoustics over the last 35 years are addressed with illustrations from ocean observations.
Download or read book Inference of the Ocean Sound Speed Profile Using Ambient Vertical Beam Noise written by Robert Thomas Taylor (Ph. D.) and published by . This book was released on 2023 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: This dissertation introduces a novel passive acoustic method for estimating the water column sound speed using the directionality of the ambient noise field measured with a vertical line array. In the absence of anthropogenic and biological sources, wind/wave sea surface interaction is the dominant source of mid-frequency noise insonifying the undersea environment. The resulting vertical noise field is anisotropic, with the directionality of the noise environment dependent on the paths of noise from the surface to the receiver. Changes in receiver depth, and associated sound speed, affect the level of ambient vertical noise at shallow elevation angles, providing the sensitivity necessary to acoustically estimate the in situ sound speed profile. Application of a clustering algorithm to an historical set of measured sound speed profiles allows for the characterization of common regional profiles. The scale and resulting undersampled nature of the ocean environment prompts the development of a novel interpolation scheme that retains acoustically important sound speed features in the region between available measurements. Motivated by the vertical stratification and motion of the water column, the interpolation scheme determines an appropriate vertical shift in depth to align sound speed features, enabling persistent features in the interpolated range between measurements. The developed method for inferring the sound speed profile combines sparse measurements of the vertical noise environment with an historical set of measured sound speed profiles and the vertical shifting method to provide an estimate of the in situ sound speed profile, with modeled results having error on the order of common active acoustic inversion methods. Finally, the method is applied to a low-frequency vertical line array data set, with results suggesting the array aperture was insufficient, and that further experimentation is needed
Download or read book Inverting for the Ocean Sound Speed Structure written by Michael Gregory Brown and published by . This book was released on 1982 with total page 200 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Development of an Acoustic Inversion Technique for Estimating Near surface Sound Speed written by Holly A. Burch and published by . This book was released on 1998 with total page 576 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Government Reports Announcements Index written by and published by . This book was released on 1985-04 with total page 568 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Model based Inversion for a Shallow Ocean Application written by and published by . This book was released on 1994 with total page 11 pages. Available in PDF, EPUB and Kindle. Book excerpt: A model-based approach to invert or estimate the sound speed profile (SSP) from noisy pressure-field measurements is discussed. The resulting model-based processor (MBP) is based on the state-space representation of the normal-mode propagation model. Using data obtained from the well-known Hudson Canyon experiment, a noisy shallow water ocean environment, the processor is designed and the results compared to those predicted using various propagation models and data. It is shown that the MBP not only predicts the sound speed quite well, but also is able to simultaneously provide enhanced estimates of both modal and pressure-field measurements which are useful for localization and rapid ocean environmental characterization.
