Download or read book Maximum Likelihood Multichannel Deconvolution of P Waves at Seismic Arrays written by Z. A. Der and published by . This book was released on 1987 with total page 176 pages. Available in PDF, EPUB and Kindle. Book excerpt: The results of maximum-likelihood multichannel deconvolution applied to array recordings and three component station networks for teleseismic P waves, are presented and interpreted in terms of possible surface reflections and other arrivals from explosions conducted at many of the world's major nuclear test sites. The deconvolution method utilizes the well known fact that P wave spectra can be decomposed into source and receiver spectral factors. The source functions obtained in the deconvolution process provide a better picture of the nature of explosion source time functions, and in particular of the presence or lack of secondary arrivals following the P wave such as pP or spall. The presence of such secondary arrivals and their effects on the first cycle of the P wave are very important in yield estimation. Significant variations in the deconvolved source time function between test sites may be associated with topography and testing practices. All of the source functions show complexity in addition to the initial P arrival and pP arrival, if present. There is also a great deal of variation between different source time functions for events at the same test site. Often, but by no means always, events occurring near each other look particularly similar. The site functions are also complex in most cases and azimuthal variations are significant in both source and receiver regions. Site and source effects contribute about equally to the energy observed in the P codes of the events analyzed. Deconvolved source time functions should be especially useful for improving estimates in the m sub b bias between test sites and to improve yield estimates since site as well at t*, instrument, and any known source spectra are removed.

Download or read book Multichannel Deconvolution of P Waves at Seismic Arrays and Three Component Stations written by Z. A. Der and published by . This book was released on 1986 with total page 116 pages. Available in PDF, EPUB and Kindle. Book excerpt: The results of a new multichannel method, applied to array recordings and three component station networks for teleseismic P waves, are presented and interpreted in terms of possible surface reflections and other arrivals from the Nevada Test Site (NTS), Novaya Zemlya, and Eastern Kazakh Test Site (EKTS) nuclear explosions. The deconvolution method utilizes the well known fact that P wave spectra can be decomposed into source and receiver spectral factors. The source functions obtained in the deconvolution process provide a better picture of the nature of explosion source time functions, and in particular of the presence or lack of secondary arrivals following the P wave such as pP or spall. The presence of such secondary arrivals and their effects on the first cycle of the P wave are very important in yield estimation. For most events at the eastern part of EKTS the source time functions appear to contain a pP arrival but they also show later, unexplained arrivals and other complexities. At other test sites often there are no clearly identifiable pP phases in the deconvolved traces. Joint deconvolution of central EKTS data using all AWRE arrays indicated strong azimuthal asymmetries in the body wave radiation. Deconvolutions of NTS events were considerably degraded by the limited signal bandwidth due to strong mantle attenuation under this test site. The site functions are also complex in most cases. Site and source effects contribute about equally to the energy observed in the P codas of the events analyzed.

Download or read book Maximum likelihood multichannel deconvolution of p waves at seismic arrays written by Z. A. Der and published by . This book was released on 1987 with total page 165 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Multichannel Deconvolution of P Waves at Seismic Arrays written by Z. A. Der and published by . This book was released on 1986 with total page 175 pages. Available in PDF, EPUB and Kindle. Book excerpt: The results of a new multichannel deconvolution method applied to array recordings of teleseismic P waves are presented and interpreted in terms of possible surface reflections and other arrivals from Nevada Test Site, Eastern Kazakh Test Site, and Astrakhan nuclear explosions. The deconvolution method uses the well-known fact that P wave spectra can be decomposed into source and receiver spectral factors. Results are discussed in terms of the outcomes of other, less complex deconvolution methods including spectral ratio techniques for estimating pP delay times and stacked deconvolution methods for enhancing the pP phase on seismic records. For most events, the deconvolved source time functions appear to contain a pP arrival but they also show later, unexplained arrivals. The site functions are also complex in many cases. About half of the late coda in P appears to be due to each of the source and the receiver. Recordings for an Eastern Kazakh cratering event show a distinctly different source function when compared to deeper, buried explosions at the same test site. From the deconvolved source-time functions, the cratering to non-cratering m sub b bias is estimated to be between 0.09 and 0.22 magnitude units. Keywords: Primary waves (Seismic waves); Seismic data; Maximum likelihood estimation; Nuclear explosion detection.

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 Technical Reports Awareness Circular TRAC written by and published by . This book was released on 1987-02 with total page 746 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Energy Research Abstracts written by and published by . This book was released on 1988 with total page 632 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Introduction to Digital Filtering in Geophysics written by O. Kulhánek and published by Elsevier. This book was released on 2012-12-02 with total page 181 pages. Available in PDF, EPUB and Kindle. Book excerpt: Introduction to Digital Filtering in Geophysics

Download or read book Deconvolution Study of P wave Land Seismic Source Signature from a Downhole Array written by Cheng-yuan Liu and published by . This book was released on 1984 with total page 482 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Monitoring a Comprehensive Test Ban Treaty written by Eystein S. Husebye and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 843 pages. Available in PDF, EPUB and Kindle. Book excerpt: An international treaty banning the testing of any nuclear device in any environment - a comprehensive test ban treaty (CTBT) - has been on the political agenda for nearly 40 years. Objections to a CTBT have been political, technical, or a combination of both. However, the possibilities seem better after the end of the Cold War. In the prevailing, cooperative disarmament climate a CTBT appears likely to be approved by most countries in 1996. Hence the great current interest in monitoring technologies and capabilities. Such issues are comprehensively addressed here, a preamble being devoted to the political developments and setbacks over the past 40 years. Since seismic means are considered the dominant monitoring element, they are explored in detail. Contributions cover network deployments, advanced signal processing, wave propagation in heterogeneous media, and seismic source representations, and a variety of techniques for source classification (including neural networks). Complementary monitoring techniques, such as hydroacoustics, radionuclides and infrasound, are also summarised. The IAEA operation for monitoring compliance with the Non-Proliferation Treaty is also presented. The book also includes eyewitness accounts of the Soviet 50 Mt megabomb development and test, as well as the efforts made by the state to monitor the nuclear test programmes of the western powers. Includes some 33 articles written by distinguished scientists active in CTBT monitoring research for decades.

Download or read book Statistics in the Environmental Earth Sciences written by Andrew T. Walden and published by Hodder Education. This book was released on 1992 with total page 330 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Spectral Analysis and Filter Theory in Applied Geophysics written by Burkhard Buttkus and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 665 pages. Available in PDF, EPUB and Kindle. Book excerpt: This state-of-the-art survey serves as a complete overview of the subject. Besides the principles and theoretical foundations, emphasis is laid on practical applicability -- describing not only classical methods, but also modern developments and their applications. Students, researchers and practitioners, especially in the fields of data registration, treatment and evaluation, will find this a wealth of information.

Download or read book Explosion Source Phenomenology written by Steven R. Taylor and published by American Geophysical Union. This book was released on 1991-01-08 with total page 290 pages. Available in PDF, EPUB and Kindle. Book excerpt: Published by the American Geophysical Union as part of the Geophysical Monograph Series, Volume 65. In March 1989, the Department of Energy (DOE) and the Lawrence Livermore National Laboratory (LLNL) sponsored a symposium on Explosion Source Phenomenology at Lake Tahoe, California. The purpose was to summarize the state of knowledge of the underground explosion source, based on U.S. experience at the Nevada Test Site (NTS). Specifically, the goals were to summarize knowledge of the explosion source, to identify limits of that knowledge and existing problems, and to propose directions of future research and data?]collection efforts.

Download or read book The Seismic Wavefield Volume 2 Interpretation of Seismograms on Regional and Global Scales written by B. L. N. Kennett and published by Cambridge University Press. This book was released on 2001 with total page 556 pages. Available in PDF, EPUB and Kindle. Book excerpt: Guide to understanding of seismograms for graduate students, researchers, professionals in academia and petroleum industry.

Download or read book Deconvolution and Inverse Theory written by V. Dimri and published by Elsevier. This book was released on 2013-10-22 with total page 249 pages. Available in PDF, EPUB and Kindle. Book excerpt: This is the first study to present simultaneously both deconvolution and inversion, two powerful tools of data analysis. Featured within this volume are various geophysical convolution models and a treatment of deconvolution for a time-varying signal. The single channel time-varying deconvolution is shown equivalent to the multichannel time-invariant deconvolution, thus a formalism and associated algorithms can handle both. Inverse theory as well as various inversion schemes are presented on the basis of a relationship between a small perturbation to the model and its effects on the observation. The information theory inversion scheme is discussed, and several types of norm of minimization presented. Additionally, concepts and results of inverse theory are applied to design a new deconvolution operator for estimating magnetization and density distribution, and the constraint of the Backus-Gilbert formalism of inverse theory is used to design a new prediction error filter for maximum entropy spectral estimates. Maximum likelihood, another high resolution method is also presented. This volume can be utilised as a graduate-level text for courses in Geophysics. Some chapters will be of use for graduate courses in Applied Mathematics, Applied Statistics, and Oceanography.

Download or read book Seismology and Structure of the Earth written by Barbara Romanowicz and published by Elsevier. This book was released on 2010-04-20 with total page 873 pages. Available in PDF, EPUB and Kindle. Book excerpt: Treatise on Geophysics: Seismology and Structure of the Earth, Volume 1, provides a comprehensive review of the state of knowledge on the Earths structure and earthquakes. It addresses various aspects of structural seismology and its applications to other fields of Earth sciences. The book is organized into four parts. The first part principally covers theoretical developments and seismic data analysis techniques from the end of the nineteenth century until the present, with the main emphasis on the development of instrumentation and its deployment. The second part reviews the status of knowledge on the structure of the Earths shallow layers, starting with a global review of the Earth's crustal structure. The third part focuses on the Earth's deep structure, divided into its main units: the upper mantle, the transition zone and upper-mantle discontinuities, the D region at the base of the mantle, and the Earth's core. The fourth part comprises two chapters which discuss constraints on Earth structure from fields other than seismology: mineral physics and geodynamics. Self-contained volume starts with an overview of the subject then explores each topic with in depth detail Extensive reference lists and cross references with other volumes to facilitate further research Full-color figures and tables support the text and aid in understanding Content suited for both the expert and non-expert

Download or read book Government Reports Annual Index written by and published by . This book was released on 1987 with total page 954 pages. Available in PDF, EPUB and Kindle. Book excerpt: Sections 1-2. Keyword Index.--Section 3. Personal author index.--Section 4. Corporate author index.-- Section 5. Contract/grant number index, NTIS order/report number index 1-E.--Section 6. NTIS order/report number index F-Z.