Propagation modeling in a three‐dimensional wedge using ray theory

1989 ◽  
Vol 85 (S1) ◽  
pp. S71-S71
Author(s):  
Evan K. Westwood
Keyword(s):  
Three Dimensional ◽  
Ray Theory ◽  
Propagation Modeling

3-D true‐amplitude finite‐offset migration

Geophysics ◽  
1993 ◽  
Vol 58 (8) ◽  
pp. 1112-1126 ◽  
Author(s):  
Jorg Schleicher ◽  
Martin Tygel ◽  
Peter Hubral
Keyword(s):  
Weight Function ◽  
A Priori ◽  
Three Dimensional ◽  
Reflection Coefficients ◽  
Ray Theory ◽  
Geometrical Spreading ◽  
Spreading Factor ◽  
Prestack Migration ◽  
The One ◽  
Paraxial Ray

Compressional primary nonzero offset reflections can be imaged into three‐dimensional (3-D) time or depth‐migrated reflections so that the migrated wavefield amplitudes are a measure of angle‐dependent reflection coefficients. Various migration/inversion algorithms involving weighted diffraction stacks recently proposed are based on Born or Kirchhoff approximations. Here a 3-D Kirchhoff‐type prestack migration approach is proposed where the primary reflections of the wavefields to be imaged are a priori described by the zero‐order ray approximation. As a result, the principal issue in the attempt to recover angle‐dependent reflection coefficients becomes the removal of the geometrical spreading factor of the primary reflections. The weight function that achieves this aim is independent of the unknown reflector and correctly accounts for the recovery of the source pulse in the migrated image irrespective of the source‐receiver configurations employed and the caustics occurring in the wavefield. Our weight function, which is computed using paraxial ray theory, is compared with the one of the inversion integral based on the Beylkin determinant. It differs by a factor that can be easily explained.

Three‐dimensional propagation modeling in shallow water

1998 ◽  
Vol 103 (5) ◽  
pp. 3029-3029 ◽  
Author(s):  
Gregory J. Orris ◽  
John S. Perkins
Keyword(s):  
Shallow Water ◽  
Three Dimensional ◽  
Propagation Modeling

scholarly journals V2I Propagation Loss Predictions in Simplified Urban Environment: A Two-Way Parabolic Equation Approach

Electronics ◽  
2020 ◽  
Vol 9 (12) ◽  
pp. 2011
Author(s):  
Mikhail Lytaev ◽  
Eugene Borisov ◽  
Andrei Vladyko
Keyword(s):  
Numerical Simulation ◽  
Parabolic Equation ◽  
Urban Environment ◽  
Vehicular Ad Hoc Networks ◽  
Ad Hoc ◽  
Three Dimensional ◽  
Propagation Loss ◽  
Propagation Modeling ◽  
Hoc Networks ◽  
Wave Propagation Modeling

This study is devoted to radio wave propagation modeling in the urban environment. Special attention has been paid to the features of vehicular ad hoc networks (VANETs) and vehicle-to-infrastructure (V2I) communications. For the first time, the three-dimensional bidirectional parabolic equation (PE) method has been applied to the specified problem. Buildings and other obstacles are modeled by impenetrable (perfectly electric conducting) cuboids. A harmonic radiation source with an arbitrary direction pattern may be modeled. Numerical simulation is performed for various propagation scenarios. A comparison with the ray-tracing (RT) method is given. The results of the numerical simulation prove the effectiveness and reliability of the proposed method. Some recommendations for deploying VANETs are obtained based on the numerical results.

On the radiation and scattering of short surface waves. Part 3

1973 ◽  
Vol 59 (1) ◽  
pp. 147-157 ◽  
Author(s):  
F. G. Leppington
Keyword(s):  
Surface Wave ◽  
Three Dimensional ◽  
Short Wave ◽  
Local Geometry ◽  
Ray Theory ◽  
Radiation Properties ◽  
Wave Region ◽  
Surface Wave Field ◽  
Inner Approximation ◽  
Time Periodic

The radiation properties of partially immersed three-dimensional bodies, in time-periodic motion, are examined in the short-wave asymptotic limit ε → 0, where ε is a non-dimensional wavelength. The method of matched expansions is used to specify an outer approximation, away from the surface wave region, and an inner approximation where the potential, in the vicinity of the obstacle and free surface, depends only on the local geometry. Finally, the radially spreading surface wave field is estimated by ray-theory arguments. Explicit details are given for the heaving and rolling of a circular dock and for the heaving motion of a hemisphere. Some speculations are made regarding the scattering properties of such obstacles.

Borehole Propagation With Undergaged Stabilizers: Theory and Validation

2019 ◽  
Vol 141 (5) ◽  
Author(s):  
Umut Zalluhoglu ◽  
Julien Marck ◽  
Hossam Gharib ◽  
Yiming Zhao
Keyword(s):  
Field Test ◽  
Test Data ◽  
Three Dimensional ◽  
Propagation Model ◽  
Test Surface ◽  
Propagation Modeling ◽  
Proposed Model ◽  
Delayed System ◽  
Actual Field

This paper discusses borehole propagation modeling in the drilling industry. A three-dimensional (3D) borehole propagation model is proposed that tracks the wellbore/stabilizer contacts caused by an overgaged borehole. The resulting model represents a nonlinear delayed system that can be efficiently used to simulate borehole propagation. Simulations are provided to show the model capabilities to capture various drilling scenarios. The predictions are also validated with actual field-test data from mud-motor and rotary-steerable operations. The proposed model can be used to (a) design mud motors and rotary steerable systems (RSSs) and evaluate their steering performance, (b) design and test surface and downhole controllers for wellplan tracking, and (c) provide predictive recommendations to help directional driller operators make steering decisions while drilling.

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