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 Directional Seismic Source Signature Deconvolution written by Gordon Anthony Roberts and published by . This book was released on 1989 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
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 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 Petroleum Abstracts written by and published by . This book was released on 1992 with total page 1716 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 Seismic Inversion Deconvolution written by Enders A. Robinson and published by . This book was released on 1999 with total page 356 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Seismic Source and Signature Deconvolution written by Anton Ziolkowski and published by . This book was released on 1985 with total page 106 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 Deconvolution of Land Seismic Data for Source and Receiver Characteristics and Near surface Structure written by Robbert van Vossen and published by . This book was released on 2005 with total page 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 165 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Deconvolution of Seismic Data written by V. K. Arya and published by . This book was released on 1982 with total page 344 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Journal written by Canadian Society of Exploration Geophysicists and published by . This book was released on 1990 with total page 792 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Seismic Source and Signature Deconvolution written by A. Ziolkowski and published by . This book was released on 1985 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Applications of source signature deconvolution to airgun seismic profiling and the measurement of attenuation from reflection seismograms written by Keith H. Wrolstad and published by . This book was released on 1978 with total page 650 pages. Available in PDF, EPUB and Kindle. Book excerpt: Deterministic source signature deconvolution is applied to the processing of marine wide angle and vertical profiler data with air-gun sources. Optimum results are obtained with a source signature measured by stacking the signal reflected from a relatively homogeneous abyssal plain sedimentary environment. This eliminates the need for the unstable inverse source-receiver ghost filter. Improved resolution of reflection event timing allows the computation of more reliable interval velocities by the T2 - X2 method, provided the layer thickness limitation of the method is not exceeded. Accurate timing of primary reflection events in the deconvolved vertical profiler data permits computation of frequency dependent attenuation by univariate least-squares regression in the Fourier transform domain. The technique successfully extracts input amplitude attenuation functions from model reflection coefficient sequences with additive random noise. This success is attributed to the stability of singular value analysis in solving the least-squares regression model. Statistical tests on the solution vectors for model and field data give criteria for evaluating their reliability. The model data studies suggest that multiple and primary events not included in the regression may be considered part of the noise term without seriously affecting the accuracy of the computed spectral ratios. The method is tested on field data from the following sedimentary environments off the coast of Oregon and northern California: a continental shelf basin, an abyssal plain environment, the base of the continental slope and two locations on the Astoria sea fan, one near the Cascadia sea channel and one north of DSDP site 174. Velocity versus depth and frequency dependent spectral ratio plots are determined for each environment. The computed surface layer interval velocity of 1.77 km/sec over a thickness of 455 m for the station north of DSDP site 174 is in good agreement with the average material type found in the drill core (sandy-silt with greater than 60% sand). Maximum attenuation coefficients are estimated from the spectral ratios for the upper sediment intervals of the study areas using typical acoustic impedance values of surface sediment types determined from nearby piston cores. Some maximum attenuation coefficients are too high suggesting the possibility of a stratigraphic component. The maximum attenuation in the upper interval for SB 46 over the Tufts abyssal plain where fine-grained material (silts and clays) is expected is 0.025 dB/m at 127 Hz compared with 0.004 dB/m at 80 Hz for the upper interval of the turbidite environment north of DSDP site 174.
Download or read book Cumulative Index Geophysics Journal of the Society of Exploration Geophysicists 1936 1988 Inclusive Early Geophysical Papers Geophysics the Leading Edge of Exploration selected Papers 1982 88 Inclusive written by William J. Zwart and published by . This book was released on 1990 with total page 782 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Analysis of the Effect of Gas Saturation on the Amplitudes of Simulated P wave and SP wave Arrivals Generated with a Simulated Downhole Seismic Source written by Brian Tanner and published by . This book was released on 1992 with total page 116 pages. Available in PDF, EPUB and Kindle. Book excerpt:
