scholarly journals Efficient 3‐D Large‐Scale Forward Modeling and Inversion of Gravitational Fields in Spherical Coordinates With Application to Lunar Mascons

2019 ◽  
Vol 124 (4) ◽  
pp. 4157-4173 ◽  
Author(s):  
Guangdong Zhao ◽  
Bo Chen ◽  
Leonardo Uieda ◽  
Jianxin Liu ◽  
Mikhail K. Kaban ◽  
...  
Keyword(s):  
Large Scale ◽  
Forward Modeling ◽  
Spherical Coordinates ◽  
Gravitational Fields ◽  
And Inversion

Tesseroids: Forward-modeling gravitational fields in spherical coordinates

Geophysics ◽  
2016 ◽  
Vol 81 (5) ◽  
pp. F41-F48 ◽  
Author(s):  
Leonardo Uieda ◽  
Valéria C. F. Barbosa ◽  
Carla Braitenberg
Keyword(s):  
Gravitational Potential ◽  
Computation Time ◽  
Forward Modeling ◽  
Gravity Gradient ◽  
Maximum Relative Error ◽  
Gravitational Acceleration ◽  
Spherical Coordinates ◽  
Gravity Gradients ◽  
Gravitational Fields ◽  
Adaptive Discretization

We have developed the open-source software Tesseroids, a set of command-line programs to perform forward modeling of gravitational fields in spherical coordinates. The software is implemented in the C programming language and uses tesseroids (spherical prisms) for the discretization of the subsurface mass distribution. The gravitational fields of tesseroids are calculated numerically using the Gauss-Legendre quadrature (GLQ). We have improved upon an adaptive discretization algorithm to guarantee the accuracy of the GLQ integration. Our implementation of adaptive discretization uses a “stack-based” algorithm instead of recursion to achieve more control over execution errors and corner cases. The algorithm is controlled by a scalar value called the distance-size ratio ([Formula: see text]) that determines the accuracy of the integration as well as the computation time. We have determined optimal values of [Formula: see text] for the gravitational potential, gravitational acceleration, and gravity gradient tensor by comparing the computed tesseroids effects with those of a homogenous spherical shell. The values required for a maximum relative error of 0.1% of the shell effects are [Formula: see text] for the gravitational potential, [Formula: see text] for the gravitational acceleration, and [Formula: see text] for the gravity gradients. Contrary to previous assumptions, our results show that the potential and its first and second derivatives require different values of [Formula: see text] to achieve the same accuracy. These values were incorporated as defaults in the software.

2.5-D forward modeling and inversion of time domain IP method

2017 ◽  
Vol 70 (0) ◽  
pp. 69-79
Author(s):  
Hideki Mizunaga ◽  
Kiyotaka Ishinaga
Keyword(s):  
Time Domain ◽  
Forward Modeling ◽  
And Inversion

scholarly journals Large-Scale 3D Modeling and Inversion of Multiphysics Airborne Geophysical Data: A Case Study from the Arabian Shield, Saudi Arabia

Minerals ◽  
2018 ◽  
Vol 8 (7) ◽  
pp. 271 ◽  
Author(s):  
Michael Zhdanov ◽  
Fouzan Alfouzan ◽  
Leif Cox ◽  
Abdulrahman Alotaibi ◽  
Mazen Alyousif ◽  
...  
Keyword(s):  
Saudi Arabia ◽  
3D Modeling ◽  
Large Scale ◽  
Geophysical Data ◽  
Arabian Shield ◽  
Airborne Geophysical Data ◽  
And Inversion

scholarly journals TESLA GPUs versus MPI with OpenMP for the Forward Modeling of Gravity and Gravity Gradient of Large Prisms Ensemble

2013 ◽  
Vol 2013 ◽  
pp. 1-15 ◽  
Author(s):  
Carlos Couder-Castañeda ◽  
Carlos Ortiz-Alemán ◽  
Mauricio Gabriel Orozco-del-Castillo ◽  
Mauricio Nava-Flores
Keyword(s):  
Parallel Computing ◽  
Graphics Processing Units ◽  
Forward Modeling ◽  
Gravity Gradient ◽  
Constant Density ◽  
Gravitational Fields ◽  
Design And Implementation ◽  
Cuda Technology ◽  
Performance Results ◽  
Graphics Processing

An implementation with the CUDA technology in a single and in several graphics processing units (GPUs) is presented for the calculation of the forward modeling of gravitational fields from a tridimensional volumetric ensemble composed by unitary prisms of constant density. We compared the performance results obtained with the GPUs against a previous version coded in OpenMP with MPI, and we analyzed the results on both platforms. Today, the use of GPUs represents a breakthrough in parallel computing, which has led to the development of several applications with various applications. Nevertheless, in some applications the decomposition of the tasks is not trivial, as can be appreciated in this paper. Unlike a trivial decomposition of the domain, we proposed to decompose the problem by sets of prisms and use different memory spaces per processing CUDA core, avoiding the performance decay as a result of the constant calls to kernels functions which would be needed in a parallelization by observations points. The design and implementation created are the main contributions of this work, because the parallelization scheme implemented is not trivial. The performance results obtained are comparable to those of a small processing cluster.

Enabling isotropic reflectivity modeling and inversion in anisotropic media

2021 ◽  
Vol 40 (4) ◽  
pp. 267-276
Author(s):  
Peter Mesdag ◽  
Leonardo Quevedo ◽  
Cătălin Tănase
Keyword(s):  
Synthetic Data ◽  
Anisotropic Media ◽  
Forward Modeling ◽  
Seismic Inversion ◽  
Stratified Medium ◽  
Effective Parameters ◽  
Elastic Parameters ◽  
Pp Wave ◽  
Anisotropic Elastic ◽  
And Inversion

Exploration and development of unconventional reservoirs, where fractures and in-situ stresses play a key role, call for improved characterization workflows. Here, we expand on a previously proposed method that makes use of standard isotropic modeling and inversion techniques in anisotropic media. Based on approximations for PP-wave reflection coefficients in orthorhombic media, we build a set of transforms that map the isotropic elastic parameters used in prestack inversion into effective anisotropic elastic parameters. When used in isotropic forward modeling and inversion, these effective parameters accurately mimic the anisotropic reflectivity behavior of the seismic data, thus closing the loop between well-log data and seismic inversion results in the anisotropic case. We show that modeling and inversion of orthorhombic anisotropic media can be achieved by superimposing effective elastic parameters describing the behavior of a horizontally stratified medium and a set of parallel vertical fractures. The process of sequential forward modeling and postinversion analysis is exemplified using synthetic data.

scholarly journals Steady Large-Scale Ocean Flows in Spherical Coordinates

Oceanography ◽  
2018 ◽  
Vol 31 (3) ◽  
pp. 42-50 ◽  
Author(s):  
Adrian Constantin ◽  
◽  
Robin Johnson
Keyword(s):  
Large Scale ◽  
Spherical Coordinates ◽  
Ocean Flows

Three-dimensional magnetotelluric axial anisotropic forward modeling and inversion

2018 ◽  
Vol 153 ◽  
pp. 75-89 ◽  
Author(s):  
Hui Cao ◽  
Kunpeng Wang ◽  
Tao Wang ◽  
Boguang Hua
Keyword(s):  
Three Dimensional ◽  
Forward Modeling ◽  
And Inversion

Efficient 3D large-scale forward modeling of gravity anomaly in space-wavenumber mixing domain

2019 ◽  
Author(s):  
Dongdong Zhao ◽  
Xiaoying Hu ◽  
Shikun Dai* ◽  
Deqiang Tao ◽  
Yinming Zhou ◽  
...  
Keyword(s):  
Gravity Anomaly ◽  
Large Scale ◽  
Forward Modeling
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