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Gabor transform

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Journal Article
Journal: Geophysics
Published: 21 December 2012
Geophysics (2013) 78 (1): V31–V41.
... stationary. We construct a set of specific windows, called molecular-Gabor (MG) windows, by solving an optimization problem, such that the seismic trace in each of the MG windows is stationary. A time-frequency ( t - f ) transform, called MG transform, can be obtained from a MG frame constructed using the MG...
FIGURES | View All (10)
Journal Article
Journal: Geophysics
Published: 02 May 2008
Geophysics (2008) 73 (3): S91–S97.
...-shift method of wavefield extrapolation is fast and stable; however, it can be cumbersome to adapt to lateral velocity variations. We address the extension of phase-shift extrapolation to lateral velocity variations by using a spatial Gabor transform instead of the normal Fourier transform. The Gabor...
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<span class="search-highlight">Gabor</span> spectrum of reflectivity obtained by dividing the <span class="search-highlight">Gabor</span> <span class="search-highlight">transform</span> of ...
Published: 31 January 2013
Figure 5. Gabor spectrum of reflectivity obtained by dividing the Gabor transform of signal of Figure  1 by the Gabor transform of signal after applying hyperbolic smoothing.
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The <span class="search-highlight">Gabor</span> <span class="search-highlight">transform</span> of the signal of Figure  1 .
Published: 31 January 2013
Figure 3. The Gabor transform of the signal of Figure  1 .
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<span class="search-highlight">Gabor</span>-<span class="search-highlight">transform</span> spectra with different Gaussian window size. The input is t...
Published: 22 November 2006
Figure 2. Gabor-transform spectra with different Gaussian window size. The input is the same synthetic trace shown in Figure 1 , but the time-frequency spectrum generated by a Gabor transform strongly depends on the given window size. From left to right, the window size used is 100, 200
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Synthetic seismic traces     (  Q  =  88  )     and their <span class="search-highlight">Gabor</span> <span class="search-highlight">transform</span> s...
Published: 02 June 2006
Figure 2. Synthetic seismic traces ( Q = 88 ) and their Gabor transform spectra (a) before and (b) after inverse Q -filtering.
Journal Article
Journal: Geophysics
Published: 12 May 2011
Geophysics (2011) 76 (3): W15–W30.
... the discrete Gabor transform, or complex-valued time-frequency decomposition, of any signal. Although the Fourier transform renders stationary convolution into exact, multiplicative factors, the Gabor transform, or windowed Fourier transform, induces only an approximate factorization of the nonstationary...
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Journal Article
Journal: Geophysics
Published: 01 October 2018
Geophysics (2018) 83 (6): V305–V314.
... was resolved here by introducing an alternative approach in resolution enhancement. Our method uses Gabor deconvolution (GD) combined with wavelet scaling. First, the seismic trace is transformed in the time-frequency domain using the Gabor transform. Subsequently, the Gabor magnitude spectrum of the seismic...
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Journal Article
Journal: Geophysics
Published: 22 February 2023
Geophysics (2023) 88 (2): L27–L35.
.... However, their precision rates often are low, thus requiring substantial manual labor to select desired events of interest. This study investigates two time-frequency methods which combine signal enhancement with automated event detection and selection, namely, (1) the sparse Gabor transform and (2...
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Journal Article
Journal: Geophysics
Published: 11 March 2009
Geophysics (2009) 74 (2): WA123–WA135.
... the short-time Fourier transform and Gabor transform. The S-transform and continuous wavelet transform are analyzed as the variable-length transforms. First we conduct a synthetic transmission experiment, and compare the frequency-dependent scattering attenuation to the theoretically predicted values. From...
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Journal Article
Journal: Geophysics
Published: 30 October 2018
Geophysics (2018) 83 (6): R681–R698.
... inversion results will be easily yielded. To deal with this problem, we decompose nonstationary seismic inversion into three subproblems. First, Q e curves are estimated at well locations using a novel scheme. Because the Gabor transform can induce approximate factorization of NSCM, the time-varying wavelet...
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Crossplots show the maximum absolute amplitude of the original data and the...
Published: 22 February 2023
Figure 9. Crossplots show the maximum absolute amplitude of the original data and the reconstructed data from (a) the sparse Gabor transform and (b) the neighboring thresholding method. Percent of changes in the maximum absolute amplitudes between the original and reconstructed data from (c
Journal Article
Journal: Geophysics
Published: 23 December 2022
Geophysics (2023) 88 (1): V1–V8.
... correction. The corresponding procedure considers frequency content of each time sample along each trace in the time-frequency domain using the Gabor transform. As such, the dominant frequency of the seismic wavelets is increased in a nonstationary manner. Performance of our method is evaluated by applying...
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(a) Synthetic data, (b) synthetic data with band-pass-filtered noise, (c) G...
Published: 22 February 2023
Figure 1. (a) Synthetic data, (b) synthetic data with band-pass-filtered noise, (c) Gabor spectrogram obtained from the Gabor transform, (d) Gabor spectrogram obtained from the sparse inversion, and (e) waveform reconstructed from the inverted Gabor coefficients.
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(a) Raw microseismic data with good signal-to-noise ratio, (b) data with ra...
Published: 22 February 2023
Figure 3. (a) Raw microseismic data with good signal-to-noise ratio, (b) data with random noise added, (c) Gabor spectrogram from the Gabor transform, (d) Gabor spectrogram from the sparse inversion, and (e) waveform reconstructed from the inverted Gabor coefficients.
Journal Article
Journal: Geophysics
Published: 01 October 2018
Geophysics (2018) 83 (6): R611–R628.
... of noise. We find that having an approximate estimate for intrinsic attenuation, even when these effects are strong, leads to improvements in resolution and a more accurate recovery of the P-wave velocity. Then, we implement and develop our method on a 2D field data set using Gabor transforms to obtain...
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Journal Article
Journal: Geophysics
Published: 02 June 2006
Geophysics (2006) 71 (3): V51–V60.
...Figure 2. Synthetic seismic traces ( Q = 88 ) and their Gabor transform spectra (a) before and (b) after inverse Q -filtering. ...
FIGURES | View All (12)
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<span class="search-highlight">Gabor</span> magnitude feature images. Seismic amplitude data are shown as the ver...
Published: 01 January 2001
F IG . 3. Gabor magnitude feature images. Seismic amplitude data are shown as the vertical traces. The magnitude of the Gabor transform is shown as an image behind the seismic data. White is zero, and the maximum value is red. There is an arbitrary time origin. (a) Large-scale Gabor kernel with 0
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<span class="search-highlight">Gabor</span> phase feature image. Seismic amplitude data are shown as the vertical...
Published: 01 January 2001
F IG . 4. Gabor phase feature image. Seismic amplitude data are shown as the vertical traces. The phase of the Gabor transform is shown as an image behind the seismic data. Red is −π phase, white is 0 phase, and blue is π phase. Large-scale Gabor kernel with 0 ms/km slope is used. Human-edited
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The final     1  /   Q  e      estimates from the QVO method. As with previ...
Published: 11 March 2009
Figure 12. The final 1 / Q e estimates from the QVO method. As with previous results, estimates of the (a) STFT and (b) Gabor transform are less stable than the (c) S-transform and (d) wavelet-transform measurements.