To: “Higher order autospectra by maximum entropy method”, by R. O. Plaisted and H. G. Peña (GEOPHYSICS, 48, 1409–1410, October, 1983).

Geophysics ◽  
1985 ◽  
Vol 50 (4) ◽  
pp. 742-743
Keyword(s):  
Signal Processing ◽  
Maximum Entropy ◽  
Maximum Entropy Method ◽  
Estimation Method ◽  
Difficult Problem ◽  
Entropy Method ◽  
Phase Estimation ◽  
Phase Information ◽  
Nonminimum Phase ◽  
Geophysical Signal

Recently Rosenblatt (1980), Lii and Rosenblatt (1982), and Matsuoka and Ulrych (1984) developed a phase estimation method for nonminimum phase MA processes by using the bispectrum which contains the required phase information of the wavelet. The computation of the bispectrum is, consequently, of importance in geophysical signal processing, particularly in the difficult problem of wavelet estimation.

On: Short note “Higher order autospectra by maximun entropy method”, by R. O. Plaisted and H. G. Peña (GEOPHYSICS, 48, 1409–1410, October, 1983).

Geophysics ◽  
1984 ◽  
Vol 49 (12) ◽  
pp. 2196-2197
Author(s):  
Toshifumi Matsuoka ◽  
Tad J. Ulrych
Keyword(s):  
Signal Processing ◽  
Short Note ◽  
Estimation Method ◽  
Difficult Problem ◽  
Higher Order ◽  
Entropy Method ◽  
Phase Estimation ◽  
Phase Information ◽  
Nonminimum Phase ◽  
Geophysical Signal

Recently Rosenblatt (1980) and Lii and Rosenblatt (1982) developed a phase estimation method for nonminimum phase MA processes by using the bispectrum which contains the required phase information of the wavelet. The computation of the bispectrum is, consequently, of importance in geophysical signal processing, particularly in the difficult problem of wavelet estimation.

Enhanced Information Recovery in 2D On-and Off-Resonance Nutation NQR using the Maximum Entropy Method

1996 ◽  
Vol 51 (5-6) ◽  
pp. 337-347 ◽  
Author(s):  
Mariusz Maćkowiak ◽  
Piotr Kątowski
Keyword(s):  
Maximum Entropy ◽  
Maximum Entropy Method ◽  
Theoretical Description ◽  
Entropy Method ◽  
Zero Field ◽  
Resonance Effects ◽  
Information Recovery ◽  
Truncation Errors ◽  
Enhanced Resolution ◽  
2D Data

Abstract Two-dimensional zero-field nutation NQR spectroscopy has been used to determine the full quadrupolar tensor of spin - 3/2 nuclei in serveral molecular crystals containing the 3 5 Cl and 7 5 As nuclei. The problems of reconstructing 2D-nutation NQR spectra using conventional methods and the advantages of using implementation of the maximum entropy method (MEM) are analyzed. It is shown that the replacement of conventional Fourier transform by an alternative data processing by MEM in 2D NQR spectroscopy leads to sensitivity improvement, reduction of instrumental artefacts and truncation errors, shortened data acquisition times and suppression of noise, while at the same time increasing the resolution. The effects of off-resonance irradiation in nutation experiments are demonstrated both experimentally and theoretically. It is shown that off-resonance nutation spectroscopy is a useful extension of the conventional on-resonance experiments, thus facilitating the determination of asymmetry parameters in multiple spectrum. The theoretical description of the off-resonance effects in 2D nutation NQR spectroscopy is given, and general exact formulas for the asymmetry parameter are obtained. In off-resonance conditions, the resolution of the nutation NQR spectrum decreases with the spectrometer offset. However, an enhanced resolution can be achieved by using the maximum entropy method in 2D-data reconstruction.

Estimating the distribution of primary reflection coefficients

Geophysics ◽  
2003 ◽  
Vol 68 (4) ◽  
pp. 1417-1422 ◽  
Author(s):  
Danilo R. Velis
Keyword(s):  
Maximum Entropy ◽  
Maximum Entropy Method ◽  
Entropy Method ◽  
Reflection Coefficients ◽  
Log Data ◽  
Neuquen Basin ◽  
Neuquén Basin ◽  
Skewness And Kurtosis

The distribution of primary reflection coefficients can be estimated by means of the maximum entropy method, giving rise to smooth nonparametric functions which are consistent with the data. Instead of using classical moments (e.g. skewness and kurtosis) to constraint the maximization, nonconventional sample statistics help to improve the quality of the estimates. Results using real log data from various wells located in the Neuquen Basin (Argentina) show the effectiveness of the method to estimate both robust and consistent distributions that may be used to simulate realistic sequences.

Maximum entropy method in phase-encoding NMR imaging

1987 ◽  
Vol 4 (1) ◽  
pp. 78-82 ◽  
Author(s):  
B. C. De Simone ◽  
F. De Luca ◽  
B. Maraviglia
Keyword(s):  
Maximum Entropy ◽  
Maximum Entropy Method ◽  
Entropy Method ◽  
Nmr Imaging ◽  
Phase Encoding
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