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wavelet multilevel analysis

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Journal Article
Published: 03 April 2019
Seismological Research Letters (2019) 90 (3): 1336–1345.
...Huailiang Li; Xianguo Tuo; Ruili Wang; Jérémie Courtois ABSTRACT We present a reliable first‐arrival picking method using wavelet multilevel analysis (WMA) and polarization analysis for high‐noise three‐component (3C) microseismic data. The proposed method is based on the autoregressive (AR) model...
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Journal Article
Journal: Geophysics
Published: 19 August 2013
Geophysics (2013) 78 (5): V219–V228.
... level lifting wavelet transform may be completed and a multilevel lifting wavelet transform can be implemented according to this rule, which is depicted in Figure  2 . It should be noted that the discrete waveform signal is finite in practical application. Therefore, when applying the (4, 4) lifting...
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Journal Article
Published: 15 July 2014
Bulletin of the Seismological Society of America (2014) 104 (4): 1663–1673.
... by a multilevel wavelet decomposition using the stationary wavelet transform. Second, the higher‐order Volterra kernels are estimated using a complete multinomial mixing of the first‐order kernel functions. Finally, the weighting of every term in this Volterra series is optimally adapted using a Levenberg...
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Journal Article
Journal: Geophysics
Published: 31 October 2006
Geophysics (2006) 71 (6): J71–J80.
... be introduced in airborne vector gravity data via platform misalignment. No autopilot was used to collect the data presented. Multilevel wavelet analysis of a signal consists of evaluating its discrete wavelet transforms and its discrete scaling function transforms using dyadic scale and shift values...
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Journal Article
Journal: Geophysics
Published: 15 March 2016
Geophysics (2016) 81 (2): KS71–KS91.
... using a noise-filtering technique such as polarization filtering ( Vidale, 1986 ; Reading et al., 2001 ), f - k analysis ( Maxwell et al., 2005 ), or wavelet-transform based denoising ( Gaci, 2014 ). Here, we apply a minimum-phase bandpass filter (10–150 Hz) and a polarization filter ( Vidale...
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Journal Article
Journal: Geophysics
Published: 03 March 2016
Geophysics (2016) 81 (2): V125–V139.
.... Our method was then further studied for a particular synchronized multilevel source array and azimuthal variations were neglected. First, tests on synthetic data were performed and the benefits and limitations of the approach were analyzed. Second, the method was tested on a field data set under...
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Journal Article
Journal: Geophysics
Published: 10 November 2020
Geophysics (2020) 85 (6): H133–H148.
... consistent with the amplitude analysis results. Therefore, we used the permittivity result of the tenth iteration as a new starting model (Figure  6c ) and updated the effective source wavelet (the red one of intersect in Figure  6c ). Note that standard applications of the crosshole GPR FWI normally...
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Series: Society of Exploration Geophysicists Geophysics Reprint Series, Society of Exploration Geophysicists Geophysics Reprint Series
Published: 01 January 2008
EISBN: 9781560801924
... Abstract In this paper we present initial results of applying Time-Reversed Acoustics (TRA) technology to salt- dome flank, seismic imaging. We created a set of syn’thetic traces representing a multilevel, walkaway VSP for a model composed of a simplified Gulf of Mexico vertical-velocity...
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Journal Article
Journal: Geophysics
Published: 01 March 2006
Geophysics (2006) 71 (2): A7–A11.
...Mark E. Willis; Rongrong Lu; Xander Campman; M. Nafi Toksöz; Yang Zhang; Maarten V. de Hoop Abstract In this paper we present initial results of applying Time-Reversed Acoustics (TRA) technology to salt-dome flank, seismic imaging. We created a set of synthetic traces representing a multilevel...
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Journal Article
Journal: Geophysics
Published: 15 November 2002
Geophysics (2003) 68 (1): 199–209.
... that compromise between the two extremes. Efforts in wavelet-based PDE solvers have grown rapidly in recent years (e.g., Goswami and Chan, 1999 ). This trend of invoking multiscale parameterization parallels another school of schemes called the multilevel ( Brandt, 1973 , 1977 ) or multigrid ( Brandt, 1982...
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Journal Article
Journal: Geophysics
Published: 27 February 2015
Geophysics (2015) 80 (2): B45–B59.
... on the accuracy of the inversion. Simultaneous AVO inversion of prestack seismic data: After satisfactory inversion analysis at the RSU-1 well and other pseudowell locations, the entire seismic data are inverted. These inversion results are discussed later when they are compared with PWI. The multilevel...
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Journal Article
Published: 13 February 2019
Seismological Research Letters (2019) 90 (2A): 591–603.
... variations, animal movement near the geyser, and human activity. First, we filter the signals from these noises by combining the Butterworth high‐pass (BH) filter and an autoregressive (AR) method in a multilevel fashion. We show that by combining these filtering techniques in a hierarchical fashion leads...
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Journal Article
Journal: Geophysics
Published: 01 January 2004
Geophysics (2004) 69 (6): 1552–1559.
... at far offsets, acting to broaden the wavelet and thus lower frequency. As a final comment on this example, one potential is the calculation of anisotropy parameters in velocity analysis. Calculating nonlinear shifts that can then be analyzed is likely to be faster than doing multidimensional...
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Journal Article
Journal: Geophysics
Published: 12 May 2017
Geophysics (2017) 82 (4): P31–P39.
... of different wavelets along the same reflectors in CIGs. This may cause difficulties for prestack analysis, but not for stacked images. The data modeled with VSDA show the imprint of the different source signatures and ghost functions in the shallowest parts of the final stacked image. At times larger than...
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Journal Article
Journal: Geophysics
Published: 21 December 2018
Geophysics (2019) 84 (1): F1–F15.
... -RTM based on a set of stable and efficient strategies, such as streamed CUDA fast Fourier transform, checkpointing-assisted time-reversal reconstruction, and adaptive stabilization. The cu Q -RTM code package can run in a multilevel parallelism fashion, either synchronously or asynchronously, to take...
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Journal Article
Published: 01 January 2016
American Mineralogist (2016) 101 (1): 222–230.
... provides evidence that magmas emitted at Eyjafjallajökull volcano, and more in general at similar other volcanic systems in ocean ridge settings, can undergo complex processes during their storage and transport in the crust, chiefly due to the presence of a multilevel plumbing system. * E-mail...
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Journal Article
Journal: Geophysics
Published: 17 August 2015
Geophysics (2015) 80 (5): M89–M12.
... widths. Similarly, Figure  11b shows that the wavelet has an impact on the seismic response because there are two distinct groups. To increase precision in our analysis, a 6D space is used for the rest of the study, in which 91% of the variance is explained. A sensitivity analysis was applied using...
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Journal Article
Journal: Geophysics
Published: 30 June 2009
Geophysics (2009) 74 (4): J35–J48.
... on an improvement of the AIC picker used for P- and/or S-wave picking in seismology ( Maeda, 1985 ) by introducing the continuous wavelet transform (CWT). The CWT acts as a band-pass filter well localized in time. The analysis of the phase part of the transform allows us to better distinguish the change...
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Journal Article
Journal: Geophysics
Published: 01 August 2006
Geophysics (2006) 71 (4): A19–A23.
...James Rickett Abstract Quantitative estimates of seismic attenuation are useful for a variety of applications, ranging from seismic-acquisition design, to seismic processing, amplitude analysis, and reservoir characterization. I frame the estimation of interval attenuation from a set of seismic...
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Journal Article
Journal: Geophysics
Published: 01 December 2014
Geophysics (2015) 80 (1): IM1–IM9.
... ; Mobli and Hoch, 2008 ; Puryear and Castagna, 2008 ), wavelet analysis ( Wang et al., 2002 ; Xu et al., 2009a ), and integrated prediction error filter analysis (PEFA) ( Nio et al., 2005 ). These methods are based on the Fourier transform, and in recent years, progress has been made to use wavelet...
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