Multi-scale parallel simulation of arbitrary waveforms for time-domain electromagnetic data

Cheng，Ming; Yang，Dikun

10.1190/segam2021-3594999.1

2021

1052-3812

1949-4645

SEG Technical Program Expanded Abstracts

2021-September

543-547

The simulation of time-domain electromagnetic fields often uses the technique of time stepping. A time stepping is a sequential computing process, as early times must be stepped through before late times. In this paper, we propose an approach to parallelize the calculation in time domain for an improved efficiency. Our approach, based on the theory of survey decomposition and the concept of scale matching, computes the time-domain responses of each time channel separately in parallel. The computational efficiency comes from two ideas. First, time-domain EM fields diffuse at later times, so each time channel can be stepped at a step length adapted to its temporal scale. Second, simulation of the entire on-time waveform may not be necessary - early time channels only need a narrow portion of the pulse width. Exploiting those two properties, our approach first empirically determines a characteristic step length (Δt) for a particular time channel. Then a step-off response is obtained by stepping at a constant Δt; the discrete impulse response can be calculated by differentiating the step-off response by Δt. Finally, the discrete impulse response is convolved with the effective part of the source waveform discretized by Δt. By experimenting with four airborne TEM waveforms and a large number of random models, we obtain a set of empirical parameters for Δt and for the effective pulse width. The improvement in efficiency is demonstrated by a 3D time-domain EM example.

第一 ; 通讯

英语

EI

20215011324759

Computation theory ; Computational efficiency ; Efficiency ; Electromagnetic fields ; Time domain analysis

Electricity and Magnetism:701 ; Computer Theory, Includes Formal Logic, Automata Theory, Switching Theory, Programming Theory:721.1 ; Production Engineering:913.1 ; Mathematics:921

2-s2.0-85120975743

Scopus

Department of Earth and Space Sciences,Southern University of Science and Technology,China

Cheng，Ming,Yang，Dikun. Multi-scale parallel simulation of arbitrary waveforms for time-domain electromagnetic data[C],2021:543-547.