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nonstationary phase-shift methods

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Journal Article
Journal: Geophysics
Published: 01 August 1999
Geophysics (1999) 64 (4): 1067–1078.
... velocity across the extrapolation step. We use nonstationary filter theory to generalize this method to nonstationary phase shift (NSPS), which allows the phase shift to vary laterally depending upon the local propagation velocity. For comparison, we derive an analytic form for the popular phase shift plus...
Journal Article
Journal: Geophysics
Published: 01 January 2001
Geophysics (2001) 66 (5): 1504–1514.
... - k method with no additional cost. Greater accuracy at slight additional expense is obtained by extending the method to a WKBJ phase-shift integral. This has the same accuracy as recursive phase shift and is similar in cost. For constant velocity, the full-Fourier domain migration filter...
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Journal Article
Journal: Geophysics
Published: 26 October 2001
Geophysics (2002) 67 (2): 594–603.
...Robert J. Ferguson; Gary F. Margrave Abstract A new depth migration method suitable for heterogeneous media is presented. The well-known phase shift plus interpolation (PSPI) method and the recently introduced nonstationary phase-shift (NSPS) method are combined into a single symmetric operator...
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Image
Comparison of the migrated image of physical model between (a) an image from the TTI imaging method (same as Figure 7a for comparison) and (b) an image from symmetric, nonstationary phase-shift migration [reprocessed for display from Figure 11 in Ferguson and Margrave (2002)].
Published: 01 January 2004
F IG . 9. Comparison of the migrated image of physical model between (a) an image from the TTI imaging method (same as Figure 7a for comparison) and (b) an image from symmetric, nonstationary phase-shift migration [reprocessed for display from Figure 11 in Ferguson and Margrave (2002) ].
Journal Article
Journal: Geophysics
Published: 29 March 2023
Geophysics (2023) 88 (2): V101–V112.
... events from similar reflectors have the same two-way traveltimes. Mapping PS data to the PP time domain leads to a nonstationary characteristic of the PS data. Nonstationary here means varying spectral content of the wavelet in PS data, which will degrade inversion results. We develop a zero-phase time...
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Journal Article
Journal: Geophysics
Published: 18 November 2015
Geophysics (2016) 81 (1): T11–T24.
... filtering methods. We have investigated the NSRI performance in the presence of input error (e.g., the phase shift and the peak frequency of the wavelet), which determined that NSRI results are reasonable in the case of moderate error. NSRI was then applied to data collected from a laboratory physical model...
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Journal Article
Journal: Geophysics
Published: 18 July 2017
Geophysics (2017) 82 (5): V311–V320.
... ( r j , τ j , φ j ) j = 1 , … , l satisfying equation  3 for a given wavelet function. Indeed, the problem is to decompose the data into a series of wavelets of different shapes, and hence the method is called morphological deconvolution. The phase-shifted wavelets...
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Journal Article
Journal: Geophysics
Published: 19 March 2020
Geophysics (2020) 85 (3): V257–V268.
... consisting in possible amplitude variations and phase shifts of the low- or high-frequency components of the records. By using the estimated source waveform, time-dependent waveforms and nonstationary wavelet matrices can be predicted at any reflection time. The method is illustrated by synthetic examples...
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Journal Article
Journal: Geophysics
Published: 12 November 2022
Geophysics (2022) 87 (1): N1–N11.
... with the noise sensitivity, we propose a new slope estimation method based on the PWD theory. We propose a forward-backward calculation of the phase-shift approximation operator to mitigate the influence of noise, as well as introducing nonstationary smoothing into the slope inversion to weaken the effect...
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Journal Article
Journal: Geophysics
Published: 03 June 2011
Geophysics (2011) 76 (4): T65–T78.
.... The new method resembles the phase-shift plus interpolation (PSPI) technique, which interpolates the wavefields that are reconstructed at several reference velocities. Synthetic examples indicate that the separation followed by interpolation is effective for models with complex geology. The new technique...
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Journal Article
Journal: Geophysics
Published: 01 June 1996
Geophysics (1996) 61 (3): 815–821.
...). Hale's method is computationally expensive because his DMO operator is temporally nonstationary, but its accuracy and simplicity have made it an industry standard. It has become a benchmark by which results from other DMO algorithms are judged. Of all the methods used to make the frequency-domain DMO...
Journal Article
Published: 01 August 2001
Russ. Geol. Geophys. (2001) 42 (8): 1171–1183.
... zones of rising mantle rocks, controlled by solid phase transitions. The development of magmatic systems is nonstationary, and crucial factors in their evolution are conditions at the boundaries of the system. Physical parameters of a medium were taken as constant in [ 20 , 21 ], but if we take...
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Series: Society of Exploration Geophysicists Geophysical References Series
Published: 01 January 2010
EISBN: 9781560802273
...) . (a) Input synthetic data. (b) Model of the noise containing amplitude and phase differences with respect to the corresponding part of the data. (c) Extracted signal. (d) Estimated noise. Figure 13. Variability of nonstationary match filter coefficients for the example shown in Figure 12...
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Journal Article
Journal: Geophysics
Published: 12 April 2023
Geophysics (2023) 88 (3): M145–M155.
... ). This method has proven effective for the synthetic seismic trace with a stationary time error. However, if nonstationary time errors are present in the synthetic seismic trace, mismatches will occur. In practice, nonstationary timing errors often occur due to inaccurate time–depth relationships and phase...
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Journal Article
Journal: Geophysics
Published: 11 April 2017
Geophysics (2017) 82 (3): R199–R217.
...Xintao Chai; Shangxu Wang; Genyang Tang ABSTRACT Seismic data are nonstationary due to subsurface anelastic attenuation and dispersion effects. These effects, also referred to as the earth’s Q -filtering effects, can diminish seismic resolution. We previously developed a method of nonstationary...
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Journal Article
Journal: Geophysics
Published: 12 February 2019
Geophysics (2019) 84 (2): R221–R234.
... use the data in Figure  2d to test the ability of our method to deconvolve the nonstationary seismogram, which recovers the high-frequency loss and phase distortion, and even the amplitude of reflectivity. Figure 1. (a) The stationary 30 Hz wavelet matrix. (b) The nonstationary 30 Hz wavelet...
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Journal Article
Journal: Geophysics
Published: 30 January 2024
Geophysics (2024) 89 (2): N45–N57.
... , 2004 , 2005a , 2005b , 2006) first proposes to construct a relative geologic time (RGT) volume by the phase unwrapping method and converts 3D seismic data volumes to the Wheeler domain using the RGT volume. Another method generates the RGT volume by globally fitting the local slopes by solving...
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Journal Article
Journal: Geophysics
Published: 28 December 2016
Geophysics (2017) 82 (1): V51–V67.
... high-resolution methods, for example, the constrained least-squares spectral analysis (CLSSA) ( Puryear et al., 2012 ). Figure 7. Column (a) displays TFRs of the nonstationary signal shown in the top row including several 25 Hz zero phase Ricker wavelets interfered in time. Column (b) displays...
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Journal Article
Journal: Geophysics
Published: 17 August 2020
Geophysics (2020) 85 (5): V385–V396.
...-frequency spectrum and developed a matching pursuit-based sparse spectral analysis (MP-SSA) method to estimate the sparse time-frequency representation of the seismic data. Further, we evaluate a generalized nonstationary convolution model concerning propagation attenuation and frequency-dependent...
Journal Article
Journal: Geophysics
Published: 08 July 2021
Geophysics (2021) 86 (4): V329–V337.
... the application of the method for interested readers. Nonstationary DecRT method improves the sparsity of Radon panels by considering the temporal and spatial frequency/phase/amplitude variations of seismic data. Attenuation, absorption, dispersion, mode-conversion, scattering, and processing side effects...
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