Sensitivity kernels and Fresnel volumes for transmitted waves

2008 ◽  
Author(s):  
Yuzhu Liu ◽  
Liangguo Dong
Keyword(s):  
Transmitted Waves ◽  
Fresnel Volumes

Imaging reflection-blind areas using transmitted PS-waves

Geophysics ◽  
2006 ◽  
Vol 71 (6) ◽  
pp. S241-S250 ◽  
Author(s):  
Yi Luo ◽  
Qinglin Liu ◽  
Yuchun E. Wang ◽  
Mohammed N. AlFaraj
Keyword(s):  
Mode Conversion ◽  
Imaging Techniques ◽  
Reverse Time ◽  
Reverse Time Migration ◽  
Reflected Waves ◽  
Prestack Migration ◽  
Reflection Data ◽  
Time Migration ◽  
Transmitted Waves ◽  
Vsp Data

We illustrate the use of mode-converted transmitted (e.g., PS- or SP-) waves in vertical seismic profiling (VSP) data for imaging areas above receivers where reflected waves cannot illuminate. Three depth-domain imaging techniques — move-out correction, common-depth-point (CDP) mapping, and prestack migration — are described and used for imag-ing the transmitted waves. Moveout correction converts an offset VSP trace into a zero-offset trace. CDP mapping maps each sample on an input trace to the location where the mode conversion occurs. For complex media, prestack migration (e.g., reverse-time migration) is used. By using both synthetic and field VSP data, we demonstrate that images derived from transmissions complement those from reflections. As an important application, we show that transmitted waves can illuminate zones above highly de-viated or horizontal wells, a region not imaged by reflection data. Because all of these benefits are obtained without extra data acquisition cost, we believe transmission imag-ing techniques will become widely adopted by the oil in-dustry.

Polarization-selective dual-band digital coding metasurface for controls of transmitted waves

2018 ◽  
Vol 51 (28) ◽  
pp. 285103 ◽  
Author(s):  
Shahid Iqbal ◽  
Shuo Liu ◽  
Rui Yuan Wu ◽  
Guo Dong Bai ◽  
Qian Ma ◽  
...  
Keyword(s):  
Dual Band ◽  
Transmitted Waves

The effect of boundaries on wave propagation in a liquid-filled porous solid: V. Transmission across a plane interface

1964 ◽  
Vol 54 (1) ◽  
pp. 409-416
Author(s):  
H. Deresiewicz ◽  
J. T. Rice
Keyword(s):  
Wave Propagation ◽  
Boundary Conditions ◽  
Body Waves ◽  
Porous Solid ◽  
Plane Interface ◽  
Plane Body ◽  
Cross Sectional ◽  
Material Constants ◽  
Transmitted Waves

abstract The passage of plane body waves across a plane interface from one to another, contiguous, porous aggregate is examined, with particular attention paid to motions involving wave lengths large in comparison with cross-sectional pore dimensions. The results are obtained for a rather general set of boundary conditions which take account of possible resistance to flow due to partial nonalignment of pores at the interface. It is found that when certain conditions of equality of material constants for the two media are met one or more of the reflected and transmitted waves are extinguished.

High-efficiency antenna-to-antenna polarization converters for customized polarization angle deflection

2020 ◽  
Vol 12 (7) ◽  
pp. 688-694
Author(s):  
Manlan Deng
Keyword(s):  
High Efficiency ◽  
Design Method ◽  
Ring Resonators ◽  
Polarization Angle ◽  
Dipole Antennas ◽  
Transmitted Waves ◽  
Angle Rotation ◽  
Transmitting Antenna ◽  
Antenna Polarization ◽  
Polarization Converters

AbstractIn this paper, an antenna-to-antenna method to design high-efficiency polarization converters was proposed. Two in-linked split ring resonators (SRRs) were used as the fundamental unit cell, which can effectively make the original linear polarization angle deflected into a customized one (include but not limited to 90°). The same as the process of energy reception and transmitting of microstrip symmetric dipole antennas, the top SRR plays the role of a receiving antenna and the bottom one acts as a transmitting antenna. Under normal illumination, the strong coupling between electric resonance and magnetic resonance can result in high transmission and broad bandwidth. Since the two SRRs act as two independently polarization selective components, the polarization angle of transmitted waves can be easily controlled by rotating the transmitting SRRs around the center. The proposed concept and the design method are validated using numerical simulations, as well as experimental results of three examples for 45, 60 and 90° polarization angle rotation, the polarization conversion ratio of which is about 92.2, 88.9 and 91.9% from 7.5 to 10 GHz.

A Novel Method to Realize Zero Phase Delay of Electromagnetic Wave

2013 ◽  
Vol 760-762 ◽  
pp. 315-319
Author(s):  
Guo Yan Dong ◽  
Xiu Lun Yang ◽  
Xiang Feng Meng
Keyword(s):  
Electromagnetic Wave ◽  
Phase Velocity ◽  
Energy Flow ◽  
Phase Delay ◽  
Delay Propagation ◽  
Transmission Process ◽  
Transmitted Waves ◽  
Novel Method ◽  
Zero Index ◽  
Zero Phase

Zero phase delay of electromagnetic wave (EMW) transmission can be realized based on the wavefront modulation of photonic crystals (PhCs). When the phase velocity is controlled perpendicular to the group velocity with wavefronts (or phasefronts) parallel to the direction of energy flow, the phase will keep constant in transmission process despite of the increase of propagating length. The phase different between the incident and transmitted waves is measured to demonstrate that the phase can remain invariable in PhCs instead of zero-index materials or zero-averaged-index PhC superlattices. This effect can be extended to other artificially engineered materials, and will open a new route to obtain perfect zero-phase delay propagation for EMW.

Active monitoring of hydraulic fracture propagation: an experimental and numerical study

2011 ◽  
Vol 51 (1) ◽  
pp. 479 ◽  
Author(s):  
Amin Nabipour ◽  
Brian Evans ◽  
Mohammad Sarmadivaleh
Keyword(s):  
Hydraulic Fracturing ◽  
Real Time ◽  
Hydraulic Fracture ◽  
Numerical Study ◽  
Fluid Pressure ◽  
Active Monitoring ◽  
Fracture Width ◽  
True Triaxial ◽  
Transmitted Waves ◽  
Triaxial Cell

Hydraulic fracturing is known as one of the most common stimulation techniques performed in oil and gas wells for maximising hydrocarbon production. It is a complex procedure due to numerous influencing factors associated with it. As a result, hydraulic fracturing monitoring techniques are used to determine the real-time extent of the induced fracture and to prevent unwanted events. Although the well-known method of monitoring is the microseismic method, active monitoring of a hydraulic fracture has shown capable of providing useful information about the fracture properties in both laboratory conditions and field operations. In this study, the focus is on laboratory experiment of hydraulic fracturing using a true-triaxial cell capable of simulating field conditions required for hydraulic fracturing. By injecting high-pressure fluid, a hydraulic fracture was induced inside a 20 cm cube of cement. Using a pair of ultrasonic transducers, transmission data were recorded before and during the test. Both cases of an open and closed hydraulic fracture were investigated. Then, using a discrete particle scheme, seismic monitoring of the hydraulic fracture was numerically modelled for a hexagonally packed sample and compared with the lab results. The results show good agreements with data in the literature. As the hydraulic fracture crosses the transducers line, signal dispersion was observed in the compressional wave data. A decrease was observed in both the amplitude and velocity of the waves. This can be used as an indicator of the hydraulic fracture width. As the fracture closes by reducing fluid pressure, a sensible increase occurred in the amplitude of the transmitted waves while the travel time showed no detectable variations. The numerical model produced similar results. As the modelled hydraulic fracture reached the source-receiver line, both amplitude and velocity of the transmitted waves decreased. This provides hope for the future real-time ability to monitor the growth of induced fractures during the fraccing operation. At present, however, it still needs improvements to be calibrated with experimental results.

Numerical computation of reflected and transmitted waves at a fluid/solid interface

2008 ◽  
Vol 123 (5) ◽  
pp. 3930-3930
Author(s):  
Laure Bossy ◽  
Marie‐Françoise Cugnet ◽  
Emmanuel Bossy ◽  
Didier Cassereau
Keyword(s):  
Numerical Computation ◽  
Solid Interface ◽  
Transmitted Waves

Measurement of the tortuosity and the viscous characteristic length of human cancellous bone via transmitted waves

2008 ◽  
Vol 123 (5) ◽  
pp. 3637-3637
Author(s):  
Naima Sebaa ◽  
Laurens Boeckx ◽  
Zine Fellah ◽  
Mouna Naas ◽  
Tom L. Goossens ◽  
...  
Keyword(s):  
Cancellous Bone ◽  
Characteristic Length ◽  
Transmitted Waves ◽  
Human Cancellous Bone

scholarly journals Generation of second mode solitary waves by the interaction of a first mode soliton with a sill

2001 ◽  
Vol 8 (4/5) ◽  
pp. 223-239 ◽  
Author(s):  
V. I. Vlasenko ◽  
K. Hutter
Keyword(s):  
Solitary Wave ◽  
Stokes Equations ◽  
Salt Water ◽  
Bottom Topography ◽  
Finite Thickness ◽  
Boussinesq Approximation ◽  
Internal Solitary Wave ◽  
Fast Wave ◽  
Transmitted Waves ◽  
Second Mode

Abstract. Results of an experimental and theoretical study of the interaction of a first mode internal solitary wave with a localised bottom topography (sill) are presented. Laboratory experiments have been performed in a 10m long and 0.33m wide channel filled with a stratified fluid. The interface between the two layers (fresh and salt water) is diffuse and has a finite thickness. Soliton-type disturbances of the interface having characteristics of the first baroclinic mode are generated at one channel end. They move along the channel and encounter an underwater obstacle (sill) in the middle of the channel, where they break into reflected and transmitted waves. Two types of internal waves are produced by the interaction: a fast first mode internal soliton and a slower (by a factor of approximately 3) second mode soliton-like wave. A numerical model, based on the two-dimensional Navier-Stokes equations in the Boussinesq approximation, is used tore produce the laboratory experiment. The detailed analysis of the horizontal and vertical structures of transmitted and reflected waves showed that the fast reflected and transmitted waves observed in the experiment can be interpreted as a first mode internal solitary wave whose characteristics are very close to those of the K-dV solitons. It is also demonstrated that the slow speed waves, generated during the interaction behind the first fast wave have vertical and horizontal structures very close to the second mode internal K-dV solitons.

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