The plane-wave time-domain algorithm for the fast analysis of transient wave phenomena

1999 ◽  
Vol 41 (4) ◽  
pp. 39-52 ◽  
Author(s):  
A.A. Ergin ◽  
B. Shanker ◽  
E. Michielssen
Keyword(s):  
Plane Wave ◽  
Time Domain ◽  
Transient Wave ◽  
Fast Analysis ◽  
Wave Phenomena

scholarly journals A Formal Time-domain Approach to Cold Magnetised Plasmas

1988 ◽  
Vol 41 (1) ◽  
pp. 55 ◽  
Author(s):  
Werner Weiglhofer
Keyword(s):  
Differential Equations ◽  
Time Domain ◽  
Scalar Potential ◽  
Coupled System ◽  
Dielectric Tensor ◽  
Tensor Operator ◽  
Transient Wave ◽  
The Time Domain ◽  
Limiting Case ◽  
Wave Phenomena

Representations of the electromagnetic and the average velocity field for a cold magnetised plasma are derived in terms of scalar potential functions. These Hertz potentials are solutions of a coupled system of integro-differential equations of second Qrder. Different from other approaches, the analysis is carried out in the time domain and is therefore especially suited for the investigation of transient wave phenomena. Furthermore, the dielectric tensor operator of the plasma is derived. Mter solving the system of integro-differential equations for a special limiting case, the applicability of the method presented is demonstrated and generalisations are discussed.

A two-level plane wave time-domain algorithm for fast analysis of EMC/EMI problems

2002 ◽  
Vol 44 (1) ◽  
pp. 152-164 ◽  
Author(s):  
K. Aygun ◽  
B. Shanker ◽  
A.A. Ergin ◽  
E. Michielssen
Keyword(s):  
Plane Wave ◽  
Time Domain ◽  
Fast Analysis ◽  
Level Plane

Fast plane-wave reverse time migration

Geophysics ◽  
2018 ◽  
Vol 83 (6) ◽  
pp. S549-S556 ◽  
Author(s):  
Xiongwen Wang ◽  
Xu Ji ◽  
Hongwei Liu ◽  
Yi Luo
Keyword(s):  
Time Delay ◽  
Plane Wave ◽  
Green’S Function ◽  
Green's Function ◽  
Time Domain ◽  
Reverse Time ◽  
Reverse Time Migration ◽  
Wave Source ◽  
Computation Cost ◽  
Time Migration

Plane-wave reverse time migration (RTM) could potentially provide quick subsurface images by migrating fewer plane-wave gathers than shot gathers. However, the time delay between the first and the last excitation sources in the plane-wave source largely increases the computation cost and decreases the practical value of this method. Although the time delay problem is easily overcome by periodical phase shifting in the frequency domain for one-way wave-equation migration, it remains a challenge for time-domain RTM. We have developed a novel method, referred as to fast plane-wave RTM (FP-RTM), to eliminate unnecessary computation burden and significantly reduce the computational cost. In the proposed FP-RTM, we assume that the Green’s function has finite-length support; thus, the plane-wave source function and its responding data can be wrapped periodically in the time domain. The wrapping length is the assumed total duration length of Green’s function. We also determine that only two period plane-wave source and data after the wrapping process are required for generating the outcome with adequate accuracy. Although the computation time for one plane-wave gather is twice as long as a normal shot gather migration, a large amount of computation cost is saved because the total number of plane-wave gathers to be migrated is usually much less than the total number of shot gathers. Our FP-RTM can be used to rapidly generate RTM images and plane-wave domain common-image gathers for velocity model building. The synthetic and field data examples are evaluated to validate the efficiency and accuracy of our method.

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