Velocity‐depth ambiguity in the dipping reflector case

Geophysics ◽  
1997 ◽  
Vol 62 (5) ◽  
pp. 1583-1585 ◽  
Author(s):  
Brijpal S. Rathor
Keyword(s):  
Acoustic Wave ◽  
Wave Velocity ◽  
Seismic Data ◽  
Seismic Events ◽  
Velocity Analysis ◽  
Vital Parameter ◽  
Acoustic Wave Velocity ◽  
Analysis Methods

Seismic or acoustic wave velocity is a vital parameter for processing and interpretation of seismic data. Various velocity analysis methods, using traveltime moveout of seismic events, have been described in literature. In certain cases, these methods provide ambiguous results. Hence, there is a need to investigate velocity‐depth ambiguity in such cases.

DETERMINATION OF PHYSICAL RESPONSE IN (Mo/AlN) SAW DEVICES

2013 ◽  
Vol 20 (02) ◽  
pp. 1350017 ◽  
Author(s):  
J. C. CAICEDO ◽  
J. A. PÉREZ ◽  
H. H. CAICEDO ◽  
H. RIASCOS
Keyword(s):  
Optical Properties ◽  
Acoustic Wave ◽  
Wave Velocity ◽  
Photoelectron Spectroscopy ◽  
Morphological Properties ◽  
Experimental Conditions ◽  
Acoustic Wave Velocity ◽  
Saw Devices ◽  
Physical Response ◽  
Aln Buffer

This paper describes the experimental conditions in surface acoustic wave (SAW) designed on aluminum nitride (AlN) films grown on Si3N4 substrates by using pulsed laser deposition. Moreover it was studied the dependency of optical properties with temperature of deposition. The thickness, measured by profilometry technology, was 150 nm for all films. Moreover, SAW devices with a Mo/AlN/Si3N4 configuration were fabricated employing AlN buffer and Mo Channel. The morphology and composition of the films were studied using atomic force microscopy (AFM), scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy analysis (XPS), respectively. The optical reflectance spectra and color coordinates of the films were obtained by optical spectral reflectometry technique in the range of 400–900 cm-1. In this work, a clear dependence in morphological properties, optical properties, frequency response and acoustic wave velocity as function of applied deposition temperature was found. It was also observed a reduction in reflectance of about 10% and an increase of acoustic wave velocity of about 1.2% when the temperature was increased from 200°C to 630°C.

Iterative P-wave velocity inversion using Markov chain Monte Carlo method

2020 ◽  
Author(s):  
Hyunggu Jun ◽  
Hyeong-Tae Jou ◽  
Han-Joon Kim ◽  
Sang Hoon Lee
Keyword(s):  
Wave Velocity ◽  
Seismic Data ◽  
Velocity Structure ◽  
Low Frequency ◽  
P Wave ◽  
Velocity Analysis ◽  
Seismic Section ◽  
Traveltime Tomography ◽  
P Wave Velocity ◽  
Frequency Components

<p>Imaging the subsurface structure through seismic data needs various information and one of the most important information is the subsurface P-wave velocity. The P-wave velocity structure mainly influences on the location of the reflectors during the subsurface imaging, thus many algorithms has been developed to invert the accurate P-wave velocity such as conventional velocity analysis, traveltime tomography, migration velocity analysis (MVA) and full waveform inversion (FWI). Among those methods, conventional velocity analysis and MVA can be widely applied to the seismic data but generate the velocity with low resolution. On the other hands, the traveltime tomography and FWI can invert relatively accurate velocity structure, but they essentially need long offset seismic data containing sufficiently low frequency components. Recently, the stochastic method such as Markov chain Monte Carlo (McMC) inversion was applied to invert the accurate P-wave velocity with the seismic data without long offset or low frequency components. This method uses global optimization instead of local optimization and poststack seismic data instead of prestack seismic data. Therefore, it can avoid the problem of the local minima and limitation of the offset. However, the accuracy of the poststack seismic section directly affects the McMC inversion result. In this study, we tried to overcome the dependency of the McMC inversion on the poststack seismic section and iterative workflow was applied to the McMC inversion to invert the accurate P-wave velocity from the simple background velocity and inaccurate poststack seismic section. The numerical test showed that the suggested method could successfully invert the subsurface P-wave velocity.</p>

Temperature dependence of surface acoustic wave velocity in thin metal films

1991 ◽  
Vol 202 (1) ◽  
pp. 171-179 ◽  
Author(s):  
Shu-Yi Zhang ◽  
Liang Guo ◽  
An Hu ◽  
Qiu-Shi Gao ◽  
Zhong-Nan Lu
Keyword(s):  
Acoustic Wave ◽  
Temperature Dependence ◽  
Surface Acoustic Wave ◽  
Wave Velocity ◽  
Metal Films ◽  
Thin Metal ◽  
Thin Metal Films ◽  
Acoustic Wave Velocity
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