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 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 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 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 Scientific and Technical Aerospace Reports written by and published by . This book was released on 1988 with total page 956 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 Optimal Seismic Deconvolution written by Jerry M. Mendel and published by Elsevier. This book was released on 2013-09-03 with total page 269 pages. Available in PDF, EPUB and Kindle. Book excerpt: Optimal Seismic Deconvolution: An Estimation-Based Approach presents an approach to the problem of seismic deconvolution. It is meant for two different audiences: practitioners of recursive estimation theory and geophysical signal processors. The book opens with a chapter on elements of minimum-variance estimation that are essential for all later developments. Included is a derivation of the Kaiman filter and discussions of prediction and smoothing. Separate chapters follow on minimum-variance deconvolution; maximum-likelihood and maximum a posteriori estimation methods; the philosophy of maximum-likelihood deconvolution (MLD); and two detection procedures for determining the location parameters in the input sequence product model. Subsequent chapters deal with the problem of estimating the parameters of the source wavelet when everything else is assumed known a priori; estimation of statistical parameters when the source wavelet is known a priori; and a different block component method for simultaneously estimating all wavelet and statistical parameters, detecting input signal occurrence times, and deconvolving a seismic signal. The final chapter shows how to incorporate the simplest of all models—the normal incidence model—into the maximum-likelihood deconvolution procedure.

Download or read book Government Reports Announcements Index written by and published by . This book was released on 1988 with total page 1162 pages. Available in PDF, EPUB and Kindle. Book excerpt:

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 Government Reports Annual Index written by and published by . This book was released on 1988 with total page 1010 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.

Download or read book Government Reports Annual Index Keyword A L written by and published by . This book was released on 1988 with total page 1016 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Bibliography and Index of Geology written by and published by . This book was released on 1990 with total page 1516 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Maximum likelihood Seismic Deconvolution written by John Joseph Kormylo and published by . This book was released on 1979 with total page 528 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Multidimensional Maximum likelihood Processing of a Large Aperture Seismic Array written by J. Capon and published by . This book was released on 1967 with total page 20 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book A Frequency domain Synthesis Procedure for Multidimensional Maximum likelihood Processing of Seismic Arrays written by Jack Capon and published by . This book was released on 1966 with total page 81 pages. Available in PDF, EPUB and Kindle. Book excerpt: A frequency-domain synthesis method for multidimensional maximum-likelihood filtering of sampled data obtained from seismic arrays is presented. This procedure is shown to possess several advantages relative to the time-domain synthesis technique. The primary advantage is that the frequency-domain method requires approximately ten times less computer time to synthesize the filter than does the time-domain technique. The details of a direct segment method for the spectral matrix estimation reqired in the frequency-domain approach are presented. In addition, the bias, variance, mean square error, limiting distribution, and other properties of the spectral estimates are discussed. The details of a Fortran IV computer program implementation of the frequency-domain method are given. The experimental results obtained by processing two events recorded at the Large Apertgure Seismic Array are presented as well as a comparison of the performance of the frequency-domain method relative to the time-domain synthesis technique. It is found that the processed noise power reduction for the frequency-domain method is typically about two out of a total of 20 db worse than that of the time-domain technique. (Author).

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 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.